Endangered and Threatened Wildlife and Plants; Threatened Species Status for the Elfin-woods Warbler, 58674-58688 [2015-24775]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 80, Number 189 (Wednesday, September 30, 2015)]
[Proposed Rules]
[Pages 58674-58688]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-24775]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket. No. FWS-R4-ES-2015-0144; 4500030113]
RIN 1018-BA94


Endangered and Threatened Wildlife and Plants; Threatened Species 
Status for the Elfin-woods Warbler

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the elfin-woods warbler (Setophaga angelae), a bird species in 
Puerto Rico, as a threatened species under the Endangered Species Act 
(Act). If we finalize this rule as proposed, it would extend the Act's 
protections to this species.

DATES: We will accept comments received or postmarked on or before 
November 30, 2015. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59 
p.m. Eastern Time on the closing date. We must receive requests for 
public hearings, in writing, at the address shown in FOR FURTHER 
INFORMATION CONTACT by November 16, 2015.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter FWS-R4-ES-2015-0144, 
which is the docket number for this rulemaking. Click the Search 
button. Then, in the Search panel on the left side of the screen, under 
the Document Type heading, click on the Proposed Rules link to locate 
this document. You may submit a comment by clicking on ``Comment Now!''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R4-ES-2015-0144; U.S. Fish and Wildlife 
Service, MS: BPHC, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Public Comments, below, for more information).

FOR FURTHER INFORMATION CONTACT: Marelisa Rivera, Deputy Field 
Supervisor, U.S. Fish and Wildlife Service, Caribbean Ecological 
Services Field Office, P.O. Box 491, Road 301 Km. 5.1, Boquer[oacute]n, 
PR 00622; telephone 787-851-7297; facsimile 787-851-7440. Persons who 
use a telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Endangered Species Act 
(Act), if we determine that a species is an endangered or threatened 
species throughout all or a significant portion of its range, we are 
required to promptly publish a proposal in the Federal Register and 
make a determination on our proposal within 1 year. Listing a species 
as an endangered or threatened species can only be completed by issuing 
a rule.
    This rulemaking proposes the listing of the elfin-woods warbler 
(Setophaga angelae) as a threatened species. The elfin-woods warbler is 
a candidate species for which we have on file sufficient information on 
biological vulnerability and threats to support preparation of a 
listing proposal, but for which development of a listing rule has until 
now been precluded by other higher priority listing activities. We are 
also proposing a rule under section 4(d) of the Act to provide for 
conservation measures for the elfin-woods warbler.
    The basis for our action. Under the Act, we may determine that a 
species is a threatened species based on any of five factors: (A) The 
present or threatened destruction, modification, or curtailment of its 
habitat or range; (B) overutilization for commercial, recreational, 
scientific, or educational purposes; (C) disease or predation; (D) the 
inadequacy of existing regulatory mechanisms; or (E) other natural or 
manmade factors affecting its continued existence. We propose to list 
this species, which is currently at risk throughout all of its range 
due to threats related to habitat modification on private lands under 
agricultural and other land use requiring vegetation clearance (Factor 
A). In addition, other natural or manmade factors, such as restricted 
distribution and lack of connectivity, genetic drift, hurricanes, and 
climate change, are considered threats (Factor E).
    We will seek peer review. We will seek comments from independent 
specialists to ensure that our determination is based on scientifically 
sound data, assumptions, and analyses. We will invite these peer 
reviewers to comment on this listing proposal.

Information Requested

Public Comments

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from other concerned governmental agencies, the 
scientific community, industry, or any other interested parties 
concerning this proposed rule. We particularly seek comments 
concerning:
    (1) The biology, range, and population trends of the elfin-woods 
warbler, including:
    (a) Habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns;
    (d) Historical and current population levels, and current and 
projected trends (especially in El Yunque National Forest and Carite 
Commonwealth Forest); and
    (e) Past and ongoing conservation measures for the species, its 
habitat or both.
    (2) Factors that may affect the continued existence of the species, 
which may include habitat modification or destruction, overutilization, 
disease, predation, the inadequacy of existing

[[Page 58675]]

regulatory mechanisms, or other natural or manmade factors.
    (3) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species and existing regulations 
that may be addressing those threats.
    (4) Additional information concerning the historical and current 
status, range, distribution, and population size of this species, 
including the locations of any additional populations of this species.
    (5) The appropriateness and scope of the proposed 4(d) rule, 
including any other actions that should be considered for inclusion.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Please note that submissions merely stating support for or 
opposition to the action under consideration without providing 
supporting information, although noted, will not be considered in 
making a determination, as section 4(b)(1)(A) of the Act (16 U.S.C. 
1531 et seq.) directs that determinations as to whether any species is 
an endangered or threatened species must be made ``solely on the basis 
of the best scientific and commercial data available.''
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We request 
that you send comments only by the methods described in the ADDRESSES 
section.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the Web site. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov. 
Please include sufficient information with your comments to allow us to 
verify any scientific or commercial information you include.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Caribbean Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).
    Because we will consider all comments and information we receive 
during the comment period, our final determination may differ from this 
proposal.

Public Hearing

    Section 4(b)(5) of the Act provides for one or more public hearings 
on this proposal, if requested. Requests must be received within 45 
days after the date of publication of this proposed rule in the Federal 
Register. Such requests must be sent to the address shown in the FOR 
FURTHER INFORMATION CONTACT section. We will schedule public hearings 
on this proposal, if any are requested, and announce the dates, times, 
and places of those hearings, as well as how to obtain reasonable 
accommodations, in the Federal Register and local newspapers at least 
15 days before the hearing.

Peer Review

    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), we will seek the expert 
opinions of four appropriate and independent specialists regarding this 
proposed rule. The purpose of peer review is to ensure that our listing 
determination is based on scientifically sound data, assumptions, and 
analyses.

Previous Federal Action

    The elfin-woods warbler was identified as a Category 2 species in 
the candidate notice of review (CNOR) published in the Federal Register 
on December 30, 1982 (47 FR 58454). Category 2 species were defined as 
species for which we had information that proposed listing was possibly 
appropriate, but for which conclusive data on biological vulnerability 
and threats were not available to support a proposed rule at the time. 
The species remained a Category 2 in subsequent annual CNORs (50 FR 
37958, September 18, 1985; 54 FR 554, January 6, 1989; 56 FR 58804, 
November 21, 1991; 59 FR 58982, November 15, 1994). The February 28, 
1996, CNOR (61 FR 7596) redefined candidates to include only species 
for which we have information needed to propose them for listing; as a 
result, elfin-woods warbler was removed from the candidate list.
    On October 25, 1999, we published a CNOR in the Federal Register 
(64 FR 57535) again classifying the elfin-woods warbler as a candidate 
species. Candidates are those fish, wildlife, and plants for which we 
have on file sufficient information on biological vulnerability and 
threats to support preparation of a listing proposal, but for which 
development of a listing regulation is precluded by other higher 
priority listing activities. The elfin-woods warbler was added to the 
candidate list with a listing priority number (LPN) of 5, indicating 
that its threats were non-imminent, but high in magnitude. This listing 
priority system was developed to ensure that we have a rational system 
for allocating limited resources in a way that ensures those species in 
greatest need of protection are the first to receive such protection. 
The listing priority system considers magnitude of threat, immediacy of 
threat, and taxonomic distinctiveness in assigning species numerical 
listing priorities on a scale from 1 to 12. In general, a smaller LPN 
reflects a greater need for protection than a larger LPN. The elfin-
woods warbler was included, and retained an LPN of 5, in our CNORs from 
2001 through 2004 (66 FR 54808, October 30, 2001; 67 FR 40657, June 13, 
2002; 69 FR 24876, May 4, 2004).
    On May 11, 2004, the Center for Biological Diversity (CBD) 
petitioned the Service to list the elfin-woods warbler as an endangered 
species under the Act (CBD 2004, pp. 34-38). The elfin-woods warbler 
was already considered a candidate species at the time the petition was 
received. Because the petition did not provide new information 
regarding the status of or threats to the species, the petition was 
addressed in the May 11, 2005 CNOR (70 FR 24870). An LPN of 5 was 
retained in the 2005 CNOR (70 FR 24870, May 11, 2005) and in subsequent 
CNORs through 2008 (71 FR 53756, September 12, 2006; 72 FR 69034, 
December 6, 2007; 73 FR 75176, December 10, 2008). The LPN was changed 
to 11 in the November 9, 2009, CNOR (74 FR 57804), reflecting that the 
magnitude of threats was moderate to low because the severity of 
threats to the species were not as strong as previously believed, and 
the threats were not currently occurring in most of the elfin-woods 
warbler's habitat; hence, the threats were non-imminent. The elfin-
woods warbler retained an LPN of 11 in the 2010 through 2014 CNORs (75 
FR 69222, November 10, 2010; 76 FR 66370, October 26, 2011; 77 FR 
69994, November 21, 2012; 78 FR 70104, November 22, 2013; 79 FR 72450, 
December 5, 2014).
    The 2011 Multi-District Litigation (MDL) settlement agreement 
specified that the Service will systematically, over a period of 6 
years, review and address the needs of 251 candidate species to 
determine if they should be added to the Federal Lists of Endangered 
and Threatened Wildlife and Plants. The elfin-woods warbler was on that 
list of candidate species. Therefore, the Service is making this 
proposed listing determination in order to comply with

[[Page 58676]]

the conditions outlined in the MDL agreement.

Background

Species Information

Species Description and Taxonomy
    The elfin-woods warbler was originally classified under the genus 
Dendroica, but is now recognized as Setophaga (Lovette et al. 2010, p. 
765). Angela and Cameron Kepler discovered the species in 1971, in the 
Dwarf forest type at El Yunque National Forest (EYNF) (Kepler and 
Parkes 1972, p. 3-5). The bird is about 12.5 centimeters (cm) (5 inches 
(in)) in length (Raffaele 1998, p. 406). The adult's upper body is 
predominantly black and white, with a stripe above the eyes, and 
conspicuous white patches on the ear coverts and sides of the neck. The 
elfin-woods warbler is often mistaken for the black and white warbler 
(Mniotilta varia), but the elfin-woods warbler is distinguished by its 
incomplete white eye-ring and entirely black crown. Immature elfin-
woods warblers are similar to adults, except that they are grayish-
green on the back, and yellowish-green on the head and underparts 
(Raffaele 1989, p. 168). The bird's call comprises a series of short, 
rapidly uttered, unmusical notes in one pitch, increasing in volume and 
ending with a short series of distinct double notes (Curson et al. 
1994, p. 156).
Life History
    Little detailed information has been published on the life history 
of the elfin-woods warbler. Some authors noted that the elfin-woods 
warbler is an extremely active warbler, moving among the dense vines of 
forest strata with more foliage cover or smaller branch tips, foraging 
insects, usually at intermediate foliage heights of 3 to 15 meter (m) 
(10 to 50 feet (ft)) (Col[oacute]n-Merced 2013, p. 2). Opportunistic 
observations indicate the elfin-woods warbler feeds on moths, 
dragonflies, and other types of insects; however, its specific diet 
remains unknown (Col[oacute]n-Merced 2013, p. 2). Raffaele et al. 
(1998, p. 406) indicated that the breeding season of the species occurs 
from March to June. Delannoy (2009, p. 1) reported that four pairs 
banded between 2004 and 2008 remained together in their territories in 
the Maricao Commonwealth Forest (MCF), suggesting that the species is 
monogamous. In addition, he reported that the elfin-woods warbler 
maintained territorial defense throughout the year and documented that 
calling activity increases from January to April and declines 
considerably during the time pairs are incubating eggs or brooding 
nestlings. Arroyo-V[aacute]zquez (1992, p. 363) reported the first 
detailed observation of two nests found in March and April of 1990 in 
aerial leaf litter at heights between 1.3 to 7.6 m (4.3 to 25 ft) and 
documented a clutch size of two to three eggs. Also, he observed that 
the pair's cup nest was woven from rootlets and fibers obtained from 
tree ferns and lined with grass leaves and down feathers. Raffaele et 
al. (1998, p. 406) further described the nest of the elfin-woods 
warbler as a compact cup, usually close to the trunk and well-hidden 
among epiphytes of a small tree. Rodr[iacute]guez-Mojica (2004, p. 22) 
reported the first nesting event inside a rotten tree stump of Palo 
Colorado (Cyrilla racemiflora) 7.0 m (23.3 ft) above ground in an 
abandoned camping area at the MCF. He described the nest structure as 
consisting of a tightly woven cup of fine plant fibers with dry leaves 
on its outside and noted that cavity-nesting is not common in warblers. 
Arroyo-V[aacute]zquez (1992, p. 363) and Rodr[iacute]guez-Mojica (2004, 
p. 22) suggested that the species selected aerial leaf litter and 
cavity-nesting sites to avoid predation. Some authors have suggested 
that elfin-woods warbler nest predators may include the pearly-eyed 
thrasher (Margarops fuscatus), Puerto Rican tanager (Nesospingus 
speculiferus), Puerto Rican screech owls (Megascops nudipes), Puerto 
Rican boa (Chilabothrus inornatus, listed as Epicrates inornatus), 
Puerto Rican racer (Alsophis portoricensis), and feral cats (Felis 
catus) (Delannoy 2009, p. 2). Other potential predators of immature and 
adult individuals include the Indian mongoose (Herpestes auropunctatus) 
and black rat (Rattus rattus) (Arroyo-V[aacute]zquez 1992, p. 364).
Historical and Current Distribution
    The elfin-woods warbler is endemic to the island of Puerto Rico and 
was initially thought to occur only in the Luquillo Mountains at EYNF 
in eastern Puerto Rico (Kepler and Parks 1972, pp. 5-6; P[eacute]rez-
Rivera 1979, p. 58). During the early 1970s, the species was reported 
in the MCF in western Puerto Rico (P[eacute]rez-Rivera 1979, p. 58; 
Cruz and Delannoy 1984, p. 92). In addition, the elfin-woods warbler 
was reported in the Toro Negro Commonwealth Forest in the Cordillera 
Central (central mountain range) (P[eacute]rez-Rivera 1979, p.58), and 
in the area of Guavate in the Carite Commonwealth Forest in east-
central Puerto Rico (P[eacute]rez-Rivera and Maldonado 1977, p. 134). 
More recently, Miranda-Castro et al. (2000, pp. 119-123) and 
Anad[oacute]n-Irizarry (2006, p. 34) conducted elfin-woods warbler 
surveys in other forests of the Cordillera Central (i.e., Tres 
Picachos, Carite, Toro Negro, Sus[uacute]a, and Guilarte Commonwealth 
Forests, and Bosque del Pueblo in Adjuntas), but did not detect the 
species.
    Between 2011 and 2013, the Service, in collaboration with the 
Puerto Rican Ornithological Society, Inc., and BirdLife International, 
conducted a study using a habitat suitability model and a single-season 
occupancy modeling approach to assess the current geographic 
distribution of the elfin-woods warbler. The project included surveys 
during the species breeding season (between January and July) within 
habitat currently occupied by the species in the MCF and predicted 
habitat within the Cordillera Central (Anad[oacute]n-Irizarry 2013, p. 
2). The predicted habitat included public and private lands within the 
municipalities of Jayuya, Ciales, Adjuntas, Ponce, Orocovis, and Juana 
D[iacute]az. The species was detected only in the MCF and adjacent 
private lands (Service 2014, p. 12).
    The elfin-woods warbler is particularly difficult to survey because 
of its small size, its constant moving behavior, and the dense 
vegetation of areas where it is found (Raffaele 1989, p. 168). In fact, 
Kepler and Parkes (1972 pp. 5-6) attribute the belated discovery of 
elfin-woods warbler to the above factors and their similarity to the 
black and white warbler. Even the vocalization of the elfin-woods 
warbler can be easily mistaken with other species. Although the 
presence of the elfin-woods warbler in the forests of the Cordillera 
Central of Puerto Rico cannot be disregarded based on the previous 
facts, the available information suggests that the current distribution 
of the species is now restricted to two populations in (1) EYNF and (2) 
MCF and adjacent private lands (Anad[oacute]n-Irizarry 2006, p. 5; 
Delannoy 2007, p. 4; Gonz[aacute]lez 2008, p. 19). The EYNF and the MCF 
are located about 150 kilometers (km) (93 miles (mi)) from each other 
(Arendt et al. 2013, p. 2). These habitats are considered essential to 
elfin-woods warbler abundance and are very important for maintaining 
healthy populations of the species (Delannoy 2007, p. 24) as they are 
the only currently know areas where the species still occurs. Although 
there is suitable habitat for the species between these two forests 
(Col[oacute]n-Merced 2013, p.51), the probability of dispersal for the 
species is low because EYNF is isolated from the central mountain range 
of Puerto Rico. Urban areas around EYNF increased by more than 2,000 
percent between 1936 and 1988, and continue to encroach on forested 
areas today

[[Page 58677]]

(Thomlinson and Rivera 2000, p. 17). Between 1988 and 1993, 
urbanization around this forest increased by 31 percent and represented 
a 5 percent loss in vegetative cover, more than 80 percent of which was 
dense forest (Thomlinson and Rivera 2000, p. 17).
Habitat
    El Yunque National Forest--EYNF is located in the Sierra de 
Luquillo in eastern Puerto Rico and covers 11,310 hectares (ha) (28,000 
acres (ac)) of the island's area (Weaver 2012, p. 1). This forest was 
proclaimed as a Crown Reserve by Spain in 1876, and as a Forest Reserve 
by the U.S. Government since 1903. It is considered the oldest forest 
reserve and largest protected area in Puerto Rico, and is managed by 
the U.S. Forest Service (USFS). Elevations of this forest range from 
100 to 1,075 m (328 to 3,526 ft) and temperatures change with altitude, 
ranging between 23.5 and 27 degrees Celsius ([deg]C) (74 to 81 degrees 
Fahrenheit ([deg]F)) at the base of the mountain to between 17 and 20 
[deg]C (63 to 68 [deg]F) on the mountain peaks (Garc[iacute]a-
Martin[oacute] et al. 1996, p. 414). Mean annual rainfall ranges from 
approximately 245 cm/year (96 in/year) at lower elevations to 
approximately 400 cm/year (157 in/year) at higher elevations (Brown et 
al. 1983, p. 11). The EYNF contains five of the six Holdridge Life 
Zones found in Puerto Rico (Ewel and Whitmore 1973, pp. 32-49). These 
five zones are the lower montane wet forest, lower montane rain forest, 
subtropical moist forest, subtropical wet forest, and subtropical rain 
forest. In 1951, Wadsworth recognized four major forest types at EYNF: 
Dwarf, Palo Colorado, Tabonuco, and Sierra Palm (Anad[oacute]n-Irizarry 
2006, p. 9).
    At EYNF, the elfin-woods warbler was originally discovered in the 
Dwarf forest (Kepler and Parkes 1972, pp. 3-5). This forest type falls 
within the lower montane rain forest life zone (Ewel and Whitmore 1973, 
p. 49) and occupies 368 ha (909 ac) of EYNF (Weaver 2012, p. 5). It is 
found on exposed peaks with short, stunted vegetation above 900 m 
(2,952 ft) elevation (Weaver 2012, p. 58). In general, the Dwarf forest 
is not well populated with birds (Snyder et al. 1987, p. 61).
    Later, the species was documented at lower elevations in the Palo 
Colorado, Tabonuco, and Sierra Palm forests (Wiley and Bauer 1985, pp. 
12-18). The Palo Colorado forest occurs within the lower montane rain 
forest life zone, between approximately 600 and 900 m (1,968 and 2,952 
ft) (Weaver 2012, p. 1). This forest type covers about 3,441 ha (8,502 
ac) of the EYNF (Weaver 2012, p. 5). This forest is mainly composed of 
fast-growing trees with height not more than 24 m (78 ft) (Lugo 2005, 
p. 506).
    The Tabonuco forest is found between 150 and 600 m (492 and 1,968 
ft) elevation, and occupies 5,663 ha (13,993 ac) of the EYNF (Weaver 
2012, p. 5). This forest is dominated by the Tabonuco tree (Dacryodes 
excelsa), which grows primarily on the subtropical wet forest life 
zones (Ewel and Whitmore 1973, p. 32). The understory of this forest is 
sparsely vegetated, and the canopy is rich in aerial plants (e.g., 
bromeliads, orchids, vines, and arboreal ferns) (Ewel and Whitmore 
1973, p. 32).
    The Sierra Palm forest (also known as palm breaks) may reach canopy 
heights of 15 m (50 ft) with 17 cm (7 in) average diameters at breast 
height (dbh) and grows mainly on steep slopes at approximately 450 m 
(1,476 ft) elevation, covering about 1,838 ha (4,541 ac) of the EYNF 
(Weaver 2012, pp. 5 and 56). The Sierra Palm forest occurs on steep 
windward slopes and poorly drained riparian areas (Lugo 2005, p. 496). 
This forest is dominated by the Sierra palm (Prestoea montana) and 
occurs within the subtropical rain forest life zone (Ewel and Whitmore 
1973, p. 4).
    Maricao Commonwealth Forest and Adjacent Lands--The main population 
of the elfin-woods warbler in western Puerto Rico occurs within the 
MCF, located between the municipalities of Maricao, San Germ[aacute]n, 
Sabana Grande, and Mayag[uuml]ez (Ricart-Pujals and Padr[oacute]n-
V[eacute]lez 2010, p. 1). This forest is currently administered by the 
Puerto Rico Department of Natural and Environmental Resources (PRDNER) 
and covers about 4,168 ha (10,543 ac) with elevations ranging between 
150 and 875 m (492 and 2870 ft) above sea level. Annual average 
temperature is 21.7 [deg]C (71 [deg]F) and annual average rainfall is 
233 cm/year (92 in/year) (Silander et al. 1986, p. 210). Three of the 
six life zones reported for Puerto Rico occur on the MCF: subtropical 
moist forest, subtropical wet forest, and lower montane wet forest 
(Ricart-Pujals and Padr[oacute]n-V[eacute]lez 2010, p. 8). The habitats 
where the elfin-woods warbler has been found within the MCF include 
Podocarpus Forest, Exposed Woodland Forest, Timber Plantations, and Dry 
Slopes Forest.
    The Podocarpus Forest occupies only 80 ha (197 ac) of the MCF and 
is located on the slopes and highest peaks (600-900 m (1,968-2,952 ft)) 
within the lower montane wet forest life zone (Department of Natural 
Resources (DNR) 1976, p. 185). Podocarpus Forest is dominated by 
Podocarpus coriaceus trees and has closed canopies and well-developed 
understories composed of tree ferns (Cyathea spp.), Sierra palms, and 
vines (Tossas and Delannoy 2001, pp. 47-53; Anad[oacute]n-Irizarry 
2006, p. 53; Gonz[aacute]lez 2008, pp. 15-16).
    The Exposed Woodland Forest occupies 2,711 ha (6,700 ac) of the MCF 
and is found in valleys, slopes, and shallow soils with a more or less 
continuous canopy (Gonz[aacute]lez 2008, pp. 15-16). These forest 
associations are found at elevations ranging from 470 to 800 m (1,542 
to 2,624 ft) within the subtropical wet forest life zone (DNR 1976, p. 
185).
    Timber Plantations occupy approximately 1,111 ha (2,745 ac) of the 
MCF in elevations ranging from 630 to 840 m (2,066 to 2,755 ft) within 
the subtropical wet forest and the subtropical moist forest life zones 
(DNR 1976, p. 185). This habitat--dominated by the Mar[iacute]a trees 
(Calophyllum calaba), eucalyptus (Eucalyptus robusta), and Honduran 
pine (Pinus caribaea)--was planted in areas that were completely 
deforested for agriculture (Delannoy 2007, p. 9; Gonz[aacute]lez 2008 
p. 5).
    Dry Slopes Forest occupies approximately 1,367.3 ha (3,377 ac) of 
the MCF in elevations ranging from 120 to 300 m (394 to 984 ft) within 
the subtropical moist forest life zone (DNR 1976, p. 185). This habitat 
is found in shallow and excessively drained serpentine-derived soils 
dominated by xerophytic vegetation, thin trees and a low open canopy. 
This forest type is more common in the southern and southeastern slopes 
of the MCF (DNR 1976, p. 185).
    Outside the MCF, the elfin-woods warbler has been detected within 
secondary forests and existing shade-grown coffee plantations 
(Gonz[aacute]lez 2008, pp. 15-16). Secondary forests are found at 
elevations ranging from 130 to 750 m (426 to 2,460 ft), and the shade-
grown coffee plantations are found at elevations ranging from 300 to 
600 m (984 to 1,968 ft) (Gonzalez 2008, p. 59; Puerto Rico Planning 
Board 2015). Also, the elfin-woods warbler has been documented at very 
low densities outside the MCF in pasturelands, Gallery forests, and 
rural residential areas, but not in sun-grown (unshaded) coffee 
plantations (Gonz[aacute]lez 2008, pp. 15-16). Young secondary forests 
developed as a result of abandonment of agriculture during the 20th 
century. These forests are less than 25 years old with an open canopy 
height of 12 to 15 m (40 to 50 ft) (Gonz[aacute]lez 2008, p. 6) and are 
found within the subtropical moist and subtropical wet forest life 
zones (DNR 1976, p. 185). Their understories

[[Page 58678]]

are well-developed and dominated by grasses, vines, and other early-
successional species (Gonz[aacute]lez 2008, p. 6). Mature secondary 
forests are over 25 years old and develop on humid to very humid, 
moderate to steep slopes. They are characterized by their closed 
canopies, reaching heights of 20 to 30 m (66 to 100 ft), and sparse to 
abundant understories (Gonz[aacute]lez 2008, p. 6). Some of these 
forests were used in the past for cultivation of shade-grown coffee and 
survived untouched because landowners abandoned agriculture activities 
(Delannoy 2007, p. 10). The shade-grown coffee plantations are covered 
with tall mature forests dominated mostly by guaba (Inga vera) and 
guaraguao (Guarea guidonia) trees. Found on moderate to steep, humid 
mountain sides, these trees reach heights of 15 to 20 m (50 to 66 ft) 
and their understories constantly develop without grasses 
(Gonz[aacute]lez 2008, p. 6). Shade-grown coffee plantations are stable 
agro-ecosystems that provide habitat, nesting, and feeding for many 
native, endemic, and migratory species. Some of the best examples of 
this habitat are found in north, northwest, and northeast MCF (Delannoy 
2007, p. 10). Studies have shown that biodiversity of plants, insects, 
reptiles, birds, and some mammals are higher in shade-grown than in 
sun-grown coffee plantations (Borkhataria et al. 2012, p. 165).
    Carite Commonwealth Forest--The Carite Commonwealth Forest (CCF) is 
within the known historical range of the elfin-woods warbler; however, 
the species was last observed in this forest about 15 years ago 
(P[eacute]rez-Rivera 2014, pers. comm.). The CCF has been managed for 
conservation by PRDNER since 1975 (DNR 1976, p. 169). This forest 
covers about 2,709 ha (6,695 ac), and ranges between 620 and 900 m 
(2,034 and 2,952 ft) in elevation (DNR 1976, p. 169). The CCF contains 
four forest types: Dwarf, Palo Colorado, Plantations, and Secondary 
(Silander et al. 1986, p. 188). These forest types are similar to the 
forests utilized by elfin-woods warbler in EYNF and MCF.
    Although the elfin-woods warbler has not been recently observed in 
this forest (Anad[oacute]n-Irizarry 2006, p. 54; Anad[oacute]n-Irizarry 
2014, pers. comm.), the habitat suitability model developed for the 
species (Col[oacute]n-Merced 2013, p. 51) suggests CCF still provides 
suitable habitat for the species due to its similarity in elevation, 
climatic conditions, and vegetation associations with EYNF and MCF. The 
CCF's similarity to EYNF and MCF suggests that this forest could 
provide habitat for the expansion of the elfin-woods warbler's current 
range to maintain the species' historical geographical and ecological 
distribution.
Population Status
    El Yunque National Forest--Kepler and Parkes (1972, p. 15) 
estimated the elfin-woods warbler population at fewer than 300 pairs 
occurring in 450 ha (1,111 acres) at EYNF. Waide (1995, p. 9) reported 
an estimated population of 138 pairs in 329 ha (812 ac) in the Dwarf 
forest at EYNF. According to Anad[oacute]n-Irizarry (2006, p. 24), the 
species' mean abundance was highest (0.48 individuals (ind)/point 
count) in the Palo Colorado forest, slightly lower (0.42 ind/point 
count) in the Dwarf forest, lowest (0.01 ind/point count) in the 
Tabonuco forest, and none were recorded in Sierra Palm forest. Arendt 
et al. (2013, p. 8) conducted bird surveys approximately monthly from 
1989 to 2006, and reported a decline of the elfin-woods warbler 
population in EYNF over that period of 17 years. The species showed a 
significant general decline from 0.2 ind/ha to 0.02 ind/ha in the Dwarf 
forest, and from 1 ind/ha to 0.2 ind/ha in the Palo Colorado forest 
(Arendt et al. 2013, p. 9).
    Maricao Commonwealth Forest and Adjacent Lands--Cruz and Delannoy 
(1984, p. 92) suggested that the elfin-woods warbler was not uniformly 
distributed throughout the MCF and that it was found in different 
habitats within three studied sites. Anad[oacute]n-Irizarry (2006, p. 
27) conducted a survey from 2003 to 2004, in 102.4 ha (253 ac) of MCF 
and recorded 778 elfin-woods warblers in 18 counts for an average of 
0.42 ind/ha/count. Gonz[aacute]lez (2008, pp. 23-28) reported the most 
recent population estimate for the elfin-woods warbler at the MCF and 
adjacent areas. Gonz[aacute]lez (2008, p. 18) estimated 97.67 elfin-
woods warbler individuals in an area of 203.2 ha (0.48 ind/ha) within 
the MCF. In areas adjacent to the MCF, he estimated 43.02 individuals 
in an area of 374.4 ha (0.11 ind/ha).
    Additionally, Gonz[aacute]lez (2008, p. 27) reported that the 
highest densities of elfin-woods warbler recorded per point-count 
stations in MCF were within the Podocarpus Forest (0.88 ind/ha). 
Moderate densities were recorded in Exposed Woodland (0.53 ind/ha), 
Timber Plantations (0.38 ind/ha), and Dry Slope Forest (0.06 ind/ha) 
(Gonz[aacute]lez 2008 p. 27). Gonz[aacute]lez (2008 p. 27) stated these 
results are similar to estimates obtained by previous studies in the 
same type of forests. In lands adjacent to the MCF, the shade-grown 
coffee plantations exhibited the highest elfin-woods warbler abundance 
(0.24 ind/ha) (Gonz[aacute]lez 2008, p. 24).
    Based on the studies mentioned above, in 2010, BirdLife 
International estimated the overall elfin-woods warbler population in 
Puerto Rico to be at least 1,800 mature individuals (Arendt et al. 
2013, p. 2).
    Carite Commonwealth Forest--In 1977, P[eacute]rez-Rivera and 
Maldonado (1977, p. 134) reported the species for the first time in the 
CCF. Two years later, P[eacute]rez-Rivera (1979, pp. 5-8) indicated 
that the species was more common than was expected when discovered. 
However, he mentioned that because the species appeared to be 
specialized to certain types of habitats, any kind of habitat 
disturbance or modification would cause a rapid species decline 
(P[eacute]rez-Rivera 1979, p. 58). The species was later recorded by 
P[eacute]rez-Rivera during the 1980s and 1990s in the following areas: 
Cerro La Santa, Camino El Seis, first recreation area near the forest 
entrance, private land near Barrio Farall[oacute]n, and Fincas Las 300 
(Delannoy 2007, pp. 22-23). Based on P[eacute]rez-Rivera's observations 
within these areas, the species seemed to be an uncommon and rare in 
CCF (i.e., 1 or 2 sightings every 10 visits) (Delannoy 2007, pp. 22-
23). The species was later detected occasionally by P[eacute]rez-Rivera 
within the same areas until it was last observed by him more than 15 
years ago (P[eacute]rez-Rivera 2014, pers. comm.).
    The surveys conducted by Anad[oacute]n-Irizarry between 2003 and 
2004, and between 2012 and 2013, failed to detect the species within 
the CCF. The study conducted during the period of 2003-2004 
(Anad[oacute]n-Irizarry 2006, p. 54) included traditional areas 
previously searched by P[eacute]rez-Rivera, and the surveys were 
conducted along 5.0 km (3.1 mi) of existing trails. The most recent 
surveys, conducted between 2012 and 2013, avoided the use of existing 
trails and included nontraditional areas, but they also failed to 
detect the species (Anad[oacute]n-Irizarry 2014, pers. comm.). However, 
during these surveys, the amount of surveyed area within nontraditional 
habitat was not significant (i.e., 15 survey stations).
    Although these studies failed to detect the species, Anad[oacute]n-
Irizarry (2006, p. 54; 2014, pers. comm.) suggested the possibility 
that the species is still present in isolated pockets of forest that 
were not searched during the studies (Delannoy 2007, p. 22). The 
apparent persistent and relatively sedentary behavior of this species 
to inhabit certain small and isolated pockets of the forest might have 
led these authors to suggest that it is possible that CCF may harbor 
undetected elfin-woods warblers (Anad[oacute]n-Irizarry 2006, p. 54; 
Delannoy

[[Page 58679]]

2007, pp. 22-23; P[eacute]rez-Rivera 2014, pers. comm.). Anad[oacute]n-
Irizarry (2006, p. 54), Delannoy (2007, pp. 22-23), and P[eacute]rez-
Rivera (2014, pers. comm.) have suggested that the species was 
extirpated from the traditional areas searched by them during the 
1980s, 1990s, and between 2003 and 2004 due to habitat modification 
activities (i.e., transmission antenna development and road 
development) that occurred in those years. If this is the case, a 
comprehensive assessment of the status of this population will require 
extensive searches covering a much larger area into the fragmented 
landscape of the CCF (Delannoy 2007, pp. 22-23). Therefore, the Service 
has contracted for a survey to include traditional and nontraditional 
areas within and beyond EYNF's and CCF's boundaries. These surveys will 
extend from September 2015 to March 2016, and will at least double the 
number of survey stations previously surveyed within CCF and will also 
include suitable habitat identified by the habitat suitability model 
outside EYNF and CCF.

Summary of Factors Affecting the Species

    Section 4 of the Act, and its implementing regulations at 50 CFR 
part 424, set forth the procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
4(a)(1) of the Act, we may list a species based on:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    Listing actions may be warranted based on any of the above threat 
factors, singly or in combination.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

    The majority of extant elfin-woods warbler populations are 
restricted to two disjunct primary habitats in montane forests at EYNF 
and at MCF and private lands adjacent to MCF. Although the elfin-woods 
warbler has not been recently observed in CCF, this forest and adjacent 
lands still contains suitable habitat for the species. The elfin-woods 
warbler needs suitable forested habitats for essential behaviors such 
as foraging, breeding, and sheltering (Anad[oacute]n-Irizarry 2006, pp. 
5-8).
    In the past, the majority of the forested areas in Puerto Rico, 
EYNF, MCF, and CCF were impacted by agricultural practices; extraction 
of timber for construction and charcoal (Dominguez-Cristobal 2000, pp. 
370-373; Dominguez-Cristobal 2008, pp. 100-103); development of 
infrastructure for utilities and communications; and construction of 
roads, recreational facilities, and trails, negatively affecting elfin-
woods warbler habitat (DNR 1976, p. 169; Waide 1995, p. 17; Delannoy 
2007, p. 4; Anad[oacute]n-Irizarry 2006, p. 28; P[eacute]rez-Rivera 
2014, pers. comm.). Currently, each agency manages these forests for 
conservation purposes operating under its authorities and mandates to 
promote habitat conservation (see Factor D. The Inadequacy of Existing 
Regulatory Mechanisms, below); habitat modification pressures from 
agriculture practices and the development of new infrastructure within 
the forests are currently very low. However, typical forest management 
of existing disturbed areas (e.g., trail maintenance, road maintenance, 
transmission antenna maintenance, and recreational facility 
improvements) and research activities (e.g., species surveys, 
endangered species reintroductions) still occur within these forests. 
The maintenance performed on roads, trails, transmission antenna 
facilities, and recreational facilities is not presently affecting 
elfin-woods warbler habitat within these forests. When a management or 
research activity is conducted, both USFS and the PRDNER closely 
coordinate with the Service during design and planning stages. These 
planning efforts minimize possible adverse effects on the species and 
its habitat. However, in contrast, the expansion of existing facilities 
(i.e., transmission antennas, access roads, access gates, 
administration buildings, utilities) within the forests is still a 
possibility and may result in the degradation of suitable habitat of 
elfin-woods warbler.
    Although the threats to the species and its habitat have been 
minimized within the lands managed and administrated by USFS and PRDNER 
within EYNF, MCF, and CCF, respectively, the species is still also 
threatened with habitat destruction, fragmentation, and degradation in 
15 percent of its suitable occupied habitat within private lands 
adjacent to MCF. The private lands adjacent to MCF are known to be 
susceptible to habitat modification caused by unsustainable 
agricultural practices and other land uses requiring vegetation 
clearance (e.g., deforestation, monoculture of minor fruits, livestock 
related activities, human-induced fires, residential use, road 
improvements). Although not known to be currently occupied, the areas 
outside EYNF and CCF are also vulnerable to these threats because they 
are not within the protected lands. In the Municipality of Maricao, the 
Puerto Rico Department of Agriculture (PRDA) has identified 301 
properties (8,442 acres) with potential to be developed as agricultural 
lands for coffee and citrus plantations (Resoluci[oacute]n Conjunta del 
Senado 2014, p. 2). Although the conversion of forested areas to sun-
grown coffee plantations is still occurring on private lands adjacent 
to MCF, the magnitude of this activity is localized and at a lower 
level than it was in the past. However, PRDA has expressed their 
intentions to increase the acreages of coffee plantations in Puerto 
Rico to 16,000 acres by 2016 (PRDA 2015, no page number). PRDA's goal 
is to provide incentives to landowners (i.e., $1,300/acre) for the 
establishment of new planting areas of sun-grown or partially shaded 
coffee (i.e., 1,000 coffee trees per acre) (Regulation 6372, p. 3-6; 
Regulation Governing the Incentives Programs of the Coffee Production 
Industry in Puerto Rico). Some of these areas, previously used for 
agriculture, were abandoned and are currently forested. The majority of 
the sun-grown coffee plantations were converted several decades ago, 
resulting in the elimination of native forest, thus reducing the 
habitat value for wildlife, including the elfin-woods warbler (Delannoy 
2007, p. 20). The most recent studies conducted in MCF and adjacent 
lands (i.e., Delannoy 2007, p. 15; Gonz[aacute]lez 2008, p. 59) did not 
detect elfin-woods warblers in sun-grown coffee plantations on 
privately owned lands adjacent to the forest. The establishment of a 
sun-grown coffee plantation requires the deforestation of the area, 
removing habitat that elfin-woods warblers are or could be using.
    The increase of urban development in private lands adjacent to EYNF 
and CCF has negatively affected elfin-woods warbler suitable habitat 
around these forests. Gould et al. (2007, pp. 29-31) suggested there is 
an increasing urbanization trend of the limited land area of eastern 
Puerto Rico where these forests are located. Urban development in this 
region increased more than 15 percent between 1991 and 2003 (Gould et 
al. 2007, pp. 29-31). Martinuzzi et al. (2007, pp. 294-296) reported 
that almost 52 percent of the island is classified under either Urban 
use (i.e., 16 percent; 142,562 ha) or Densely Populated Rural

[[Page 58680]]

use (i.e., 36 percent; 320,219 ha) classes. The urban-use class 
enhances the contiguity between the compact urban areas across the 
island, and gives an accurate view of how an ``urban ring'' encircles 
interior mountainous and protected areas like EYNF and CCF (Martinuzzi 
et al. 2007, p. 294). The densely populated rural-use class surrounds 
the urban-use areas and represents most of the territory where human 
developments expand out from the urban centers following secondary 
routes (Martinuzzi et al. 2007, p. 294). Although the most evident 
land-use changes in the last 25 years have been the intensification of 
urbanization that surrounds these forests (Helmer 2004, pp. 33-35, 
Gould et al. 2007, pp. 29-31, Martinuzzi et al. 2007, p. 294), it is 
not known how much of these lands currently contain habitat suitable 
for elfin-woods warbler.
Conservation Efforts To Reduce the Present or Threatened Destruction, 
Modification, or Curtailment of Its Habitat or Range
    In 2014 the Service developed a candidate conservation agreement 
(CCA) with USFS and PRDNER to promote the conservation of the elfin-
woods warbler. The purpose of the CCA is to implement measures to 
conserve, restore, and improve elfin-woods warbler habitat and 
populations within EYNF and MCF (Service 2014, p. 6). The CCA provides 
that PRDNER and USFS will promote, develop, and implement the best 
management practices to avoid any potential threat to suitable and 
occupied elfin-wood warbler habitat and populations. It also provides 
that both agencies will implement restoration and habitat enhancement 
efforts within degraded areas of EYNF and MCF. The agencies will also 
(1) determine the habitat use, movement, and activity patterns of the 
species; (2) design and establish long-term population monitoring 
programs; and (3) develop outreach and education programs to improve 
mechanisms to promote habitat conservation and restoration within 
private lands adjacent to both forests.
    Although the elfin-woods warbler also occurs on privately owned 
lands not covered by the CCA, these areas adjacent to MCF are part of a 
habitat restoration initiative in southwestern Puerto Rico implemented 
by the Service since 2010, through the Partners for Fish and Wildlife 
(PFW) and Coastal (CP) Programs. The PFW and CP are voluntary programs 
that provide technical and financial assistance to landowners to 
implement restoration and conservation practices on their lands for a 
particular amount of time. These programs promote the restoration of 
degraded habitat that was likely occupied by the species before the 
conversion to agricultural lands and that may be restored as suitable 
elfin-woods warbler habitat in the future. In some cases, occupied 
suitable habitat for the species is enhanced and protected through 
cooperative agreements with the private landowners.
    Between 2010 and 2014, a total of 522 ha (1,290 acres) of degraded 
tropical upland forest and 21 km (13 miles) of riparian buffers have 
been restored and conserved through these programs in collaboration 
with the Natural Resources Conservation Service (NRCS), Farm Service 
Agency (FSA), PRDNER, Envirosurvey Inc. (a local nongovernmental 
organization), and other partners. Although this initiative promotes 
the restoration and enhancement of degraded habitat adjacent to the MCF 
and may potentially provide suitable habitat for the elfin-woods 
warbler, challenges such as limited resources and uncertainty about 
land owner participation may affect the implementation of management 
practices that mitigate impacts of agricultural practices.
Summary of Factor A
    The elfin-woods warbler's restricted distribution makes it 
vulnerable to habitat destruction and modification. The agricultural 
activities and development projects on private lands adjacent to EYNF, 
MCF, and CCF may result in the loss or fragmentation of the species' 
suitable habitat. However, the elfin-woods warbler has been reported on 
private lands only outside MCF; private lands adjacent to EYNF and CCF 
need to be appropriately surveyed. The majority of extant elfin-woods 
warbler populations occur in public lands managed for conservation 
purposes where activities that may affect the species or its habitat 
are regulated, and measures to minimize or avoid those impacts are 
being implemented based on management plans or agencies management 
mandates. Therefore, we believe that habitat curtailment or 
modification is a threat to the elfin-woods warbler.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    Based on the available information, this factor has not been 
documented as a threat to the elfin-woods warbler.

Factor C. Disease or Predation

    Delannoy (2009, p. 2) indicated that Puerto Rican sharp-shinned 
hawk (Accipiter striatus venator) infrequently prey on elfin-woods 
warbler. Other potential elfin-woods warbler nest predators may include 
the pearly-eyed thrasher, Puerto Rican tanager, Puerto Rican screech 
owl, Puerto Rican boa, Puerto Rican racer, and feral cat (Delannoy 
2009, p. 2). Additionally, Arroyo-V[aacute]zquez (1992, p. 364) noted 
that the Indian mongoose and black rat are potential egg and nestling 
predators. Nonetheless, we are not aware of any scientific or 
commercial information that predation of elfin-woods warblers is having 
an adverse effect on the species, and therefore we believe that 
predation is not a threat to the elfin-woods warbler. Similarly, we 
have no evidence of any disease affecting the species.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    In 1999, the Commonwealth of Puerto Rico approved the Law No. 241-
1999, known as the New Wildlife Law of Puerto Rico (Nueva Ley de Vida 
Silvestre de Puerto Rico). The purpose of this law is to, among other 
things, protect, conserve, and enhance both native and migratory 
wildlife species; declare as property of Puerto Rico all wildlife 
species within its jurisdiction; issue permits; regulate hunting 
activities; and regulate exotic species. In 2004, the Commonwealth of 
Puerto Rico approved the Regulation Governing the Management of 
Vulnerable and Endangered Species on the Commonwealth of Puerto Rico 
(Regulation 6766; Reglamento para Regir el Manejo de las Especies 
Vulnerables y en Peligro de Extinci[oacute]n en el Estado Libre 
Asociado de Puerto Rico). Regulation 6766 prohibits collecting, 
killing, or harming species listed under Territorial law, as well as 
possessing, transporting, or selling items derived from listed species, 
and requires authorization from the PRDNER Secretary for any action 
that may affect designated critical habitat of listed species under 
this regulation (Departamento de Recursos Naturales y Ambientales 2004, 
pp. 9, 18). In 2004, the Commonwealth of Puerto Rico included the 
elfin-woods warbler in Regulation 6766 as a ``vulnerable species'' (a 
species that, although is not listed as endangered or critically 
endangered, faces a high risk of extinction in a foreseeable future).
    In addition to laws that specifically protect the elfin-woods 
warbler, MCF and CCF are protected under Puerto Rico's Forests Law (Law 
No. 133-1975;

[[Page 58681]]

Ley de Bosques de Puerto Rico), as amended in 2000, which prohibits 
causing damage to and collection of flora and fauna in public forests. 
Moreover, all Commonwealth forests are designated as Critical Wildlife 
Areas (CWA) by PRDNER. The CWA designation constitutes a special 
recognition by this agency with the purpose of providing information to 
other Commonwealth and Federal agencies about the conservation needs of 
these areas, and assisting permitting agencies in precluding negative 
impacts as a result of permit approvals or endorsements (PRDNER 2005, 
p. 6).
    The Migratory Bird Treaty Act (MBTA) (16 U.S.C. 703-712) provides 
protection for the elfin-woods warbler, which is defined as a migratory 
bird under the MBTA. The MBTA makes it unlawful to pursue; hunt; take; 
capture; kill; attempt to take, capture, or kill; possess; offer for 
sale; sell; offer to barter; barter; offer to purchase; purchase; 
deliver for shipment; ship; export; import; cause to be shipped, 
exported, or imported; deliver for transportation; transport or cause 
to be transported; carry or cause to be carried; or receive for 
shipment, transportation, carriage, or export, any migratory bird, or 
any part, nest, or egg of such bird, or any product, whether or not 
manufactured, which consists of, or is comprised in whole or part, of 
any such bird, or any part, nest, or egg thereof. However, no 
provisions in the MBTA prevent habitat destruction unless direct 
mortality or destruction of active nests occurs.
    Finally, the elfin-woods warbler co-occurs with other species that 
are listed under the Act. In the EYNF, the species co-occurs with the 
Puerto Rican sharp-shinned hawk (Accipiter striatus venator), Puerto 
Rican boa, Puerto Rican broad-winged hawk (Buteo platypterus 
brunnescens), Puerto Rican parrot (Amazona vittata), and several 
federally listed plants: Styrax portoricensis, uvillo (Eugenia 
haematocarpa), Lepanthes eltoroensis, Pleodendron macranthum, capa rosa 
(Callicarpa ampla), Ternstroemia luquillensis, Ternstroemia 
subsessilis, and Ilex sintenisii. In the MCF, the species co-occurs 
with the Puerto Rican sharp-shinned hawk, Puerto Rican boa, and several 
federally listed plants: Cranichis ricartii, Gesneria pauciflora, palo 
de rosa (Ottoschulzia rhodoxylon), Ternstroemia luquillensis, higuero 
de sierra (Crescentia portoricensis), and Cordia bellonis. Because of 
the occurrence of these federally listed species within the same 
habitat where elfin-woods warblers occur, any Federal action, funding, 
or permit within these forests or in private lands adjacent to these 
forests that may affect these listed species requires a section 7 
consultation under the Act. Therefore, the elfin-woods warbler may 
benefit from indirect protection of these listed species (i.e., 
implementation of habitat restoration practices and habitat 
protection).
    Based on the information currently available to us, the Federal and 
Commonwealth regulatory mechanisms are being implemented and are 
functioning as designed. Lack of enforcement of these laws and 
regulations has not been identified as having a negative impact to the 
species or exacerbating other negative effects to the species. 
Therefore, we do not find the existing regulations to be inadequate.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Hurricanes and Climate Change
    The geographic location of islands in the Caribbean Sea makes them 
prone to hurricane impacts (Wiley and Wunderle 1993, p. 320). In fact, 
the frequency of hurricane occurrences is higher in the southeastern 
United States and the Caribbean than other regions of the world (Wiley 
and Wunderle 1993, p. 320). Hurricanes can have both direct and 
indirect effects on bird populations, which may determine the 
characteristics of local avifauna (Wauer and Wunderle 1992, p. 656; 
Wunderle et al. 1992, p. 323). Arendt et al. (2013, p. 2) suggested 
that catastrophic weather events such as hurricanes can negatively 
affect the elfin-woods warbler due to its restricted distribution and 
low number of individuals. Some species may cope with hurricane-induced 
changes by selecting different prey items, while others may switch 
their foraging behavior and locations (Wauer and Wunderle 1992, p. 657; 
Wunderle et al. 1992, pp. 323-326).
    The frequency of hurricane-induced damage equivalent to F3 (severe) 
on the Fujita scale (Fujita 1971) is at least three times greater in 
the northeastern quadrant of Puerto Rico, where EYNF and CCF are 
located, compared to the rest of the island (White et al. 2014, p. 30). 
In contrast, the western side of Puerto Rico, where MCF is located, is 
subject to different hurricane trajectories and risks than the eastern 
portion of the island (White et al. 2010, p. 16). For example, in 1998, 
Hurricane Georges struck MCF, which previously had been spared from 
hurricanes since 1932 (Tossas 2006, p. 81). Hence, studies of the 
effects of hurricanes on bird populations in Puerto Rico are limited to 
the northeastern region and little is known about how bird species are 
affected elsewhere on the island (Tossas 2006, p. 81).
    Delannoy (2007, p. 24) suggested that elfin-woods warbler 
populations at MCF appeared to be stable. However, studies conducted 
from 1989 to 2006 at EYNF documented a declining trend of the elfin-
woods warbler population during the study period (Arendt et al. 2013, 
pp. 8-9). Arendt et al. (2013, p. 8) stated that this documented 
downward population trend could be related to intrinsic causes (e.g., 
physiological, genetic). Nonetheless, they further suggest that it is 
more likely that natural habitat conversion and degradation, resulting 
from cyclonic events, are playing an important role in the species' 
decline at EYNF. Direct effects of hurricanes on habitat include 
massive defoliation, snapped and wind-thrown trees, massive tree 
mortality, and landslides (Lugo 2008, p. 368). For example, Hurricane 
Hugo (1989) and Hurricane Georges (1998) caused extensive damage in 
EYNF, which damage may have adversely impacted the elfin-woods 
warbler's primary habitat (Arendt et al. 2013, pp. 8-9). Arroyo (1991, 
p. 55) noted that the species was not recorded during 1990 from areas 
it was reported from previously at EYNF. This forest was heavily 
damaged by Hurricane Hugo, with more than 80 percent of the forest 
completely defoliated (Boucher 1990, p. 164). In contrast, at the MCF, 
Arroyo (1991, pp. 55-56) recorded an apparent vertical migration 
pattern of the species during months of heaviest rains. Moreover, 
Tossas (2006, p. 84) found that the elfin-woods warbler was one of two 
species that recovered within a year to pre-hurricane population levels 
after Hurricane Georges. This finding suggested that warblers abandoned 
defoliated sites immediately after the hurricane and shifted to 
protected patches with adequate foraging substrate and prey until the 
defoliated sites recovered (Tossas 2006, p. 84). Arendt et al. (2013, 
p. 9) indicated that these contrasting findings may be the result of 
disproportionate damage caused by storms in the respective forests. 
Moreover, the landscape at EYNF is different from that of the MCF in 
that at EYNF there is no continuous forested vegetation beyond the 
forest boundaries mainly due to conversion of agricultural lands and 
lowland broadleaf forests to urbanized areas (Lugo et al. 2004, p. 29). 
Therefore, the probability of dispersion to undamaged areas within and 
outside EYNF would be reduced for the elfin-

[[Page 58682]]

woods warbler depending on the damages to the vegetation. The lack of 
suitable habitat around the EYNF also reduces the probability of elfin-
woods warbler re-colonization from the MCF, which is 150 km (93 mi) 
away (Arendt et al. 2013, p. 2).
    Anad[oacute]n-Irizarry (2006, p. 54), Delannoy (2007, p. 24), and 
Anad[oacute]n-Irizarry (2014, pers. comm.) have suggested the elfin-
woods warbler no longer exists within CCF. P[eacute]rez-Rivera (2014, 
pers. comm.) has suggested that the habitat modification caused by 
Hurricane Hugo and Hurricane Georges at CCF may have had a negative 
effect on the elfin-woods warbler. However, he acknowledged that before 
concluding the species was extirpated from the forest due to these 
climatological events, a formal and extensive survey should be 
conducted to include nontraditional areas within and outside of CCF 
(P[eacute]rez-Rivera 2014, pers. comm.). He suggested hurricanes might 
be detrimental to low densities and habitat-specialized species, but at 
the same time might benefit insectivorous species like the elfin-woods 
warbler. In 1989, a month after Hurricane Hugo, P[eacute]rez-Rivera 
(1991, pp. 474-475) recorded the Antillean euphonia (Euphonia musica) 
shifting its feeding and foraging behavior in CCF as a result of the 
habitat disturbance following the hurricane. Some authors (i.e., Wauer 
and Wunderle 1992, p. 657; Wunderle et al. 1992, pp. 323-326) have 
suggested that the frequency of hurricanes in the Caribbean may be 
determining some of the characteristics of the local avifauna, such as 
the shifting into new habitats due to hurricane-induced changes.
    Hurricanes can have positive effects on forest and bird ecology by 
temporarily increasing forest productivity (Wiley and Wunderle 1993, p. 
337), particularly for species with ample distribution (White et al. 
2014, p. 31). However, the immediate negative effects of these powerful 
atmospheric events for a species with demographically vulnerable 
populations, such as the elfin-woods warbler, outweigh the benefits 
accrued via short-term primary productivity of vegetation (White et al. 
2014, p. 31). This might explain the declining elfin-woods warbler 
population trend documented by Arendt et al. (2013, pp. 8-9) at EYNF.
    Studies predict an increase in hurricane intensity in the Atlantic, 
with higher wind speeds and greater amounts of precipitation, but a 
reduction in the overall number of storms (Jennings et al. 2014, p. 8). 
As mentioned above, hurricanes may result in direct negative effects to 
the species and its habitat.
    Based on the above information, it is possible that the elfin-woods 
warbler could experience local extinction with these catastrophic 
weather events. While the species appears to have the ability to 
temporarily move to undisturbed areas and survive in MCF, such 
dispersal ability has not been documented at EYNF. Having two 
geographically separate populations on both ends of Puerto Rico may 
benefit the elfin-woods warbler since, based on the history of 
hurricanes striking the Island, it is unlikely for both EYNF and MCF to 
be impacted by the same weather system at once. However, the fact that 
there are only two known populations left makes the species more 
vulnerable to extinction if one is lost due to a catastrophic weather 
event. It is important to note, however, that there are no specific 
studies corroborating hurricanes as a main cause of elfin-woods warbler 
population declines at EYNF and MCF, nor that they caused the apparent 
extirpation of the species from CCF.
    Regarding climate, general long-term changes have been observed, 
including changes in amount of precipitation, wind patterns, and 
extreme weather events (e.g., droughts, heavy precipitation, heat 
waves, and the intensity of tropical cyclones) (Intergovernmental Panel 
on Climate Change (IPCC) 2007, p. 30). For example, projected decreases 
in precipitation in the Caribbean suggest drier wet seasons, and even 
drier dry seasons (Jennings et al. 2014, p. 1).
    As previously mentioned, the elfin-woods warbler is currently known 
only from specific habitat types at EYNF and MCF, which makes the 
species susceptible to the effects of climate change. It has been 
stated that higher temperatures, changes in precipitation patterns, and 
any alteration in cloud cover will affect plant communities and 
ecosystem processes in EYNF (Lasso and Ackerman 2003, pp. 101-102). In 
fact, the distribution of tropical forest life zones in the Caribbean 
is expected to be altered due to both intensified extreme weather 
events and progressively drier summer months (Wunderle and Arendt 2011, 
p. 44). At EYNF, such alteration may allow low-elevation Tabonuco 
forest species to colonize areas currently occupied by Palo Colorado 
forest (Scatena and Lugo 1998, p. 196). Dwarf forests at EYNF also are 
very sensitive to climate change because of their occurrence in 
narrowly defined environmental conditions (Lasso and Ackerman 2003, p. 
95). Dwarf forest epiphytes may experience moisture stress due to 
higher temperatures and less cloud cover with a rising cloud base, 
affecting epiphyte growth and flowering (Nadkarni and Solano 2002, p. 
584). As previously mentioned, both the Palo Colorado and Dwarf forests 
have been reported to have the highest elfin-woods warbler mean 
abundance (Anad[oacute]n-Irizarry 2006, p. 24). Although the available 
information predicting changes in habitat due to climate change 
pertains to EYNF, similar changes would be expected for the MCF and 
CCF, which lies within two of the same life zones as EYNF.
    As indicated above, such climate changes are likely to alter the 
structure and distribution of the habitat used by the elfin-woods 
warbler. According to Arendt et al. (2013, p. 9), approximately 50 
percent of the Caribbean birds show medium to high vulnerability to 
climate change. Based on that information, species that are dependent 
on specific habitat types, and that have limited distribution or have 
become restricted in their range, like the elfin-woods warbler, will be 
most susceptible to the impacts of climate change. However, while 
continued change is expected, the magnitude and rate of that change is 
unknown in many cases. In tropical and subtropical forests, significant 
knowledge gaps exist in predicting the response of natural systems to 
climate change, and uncertainties exist with studies forecasting trends 
in climate (Jennings et al. 2014, p. 33). Moreover, regionally 
downscaled climate models projecting temperature and precipitation 
patterns at fine scales are not readily available for locations within 
the Caribbean region, including Puerto Rico (Jennings et al. 2014, p. 
33). While existing large-scale global climate models are useful in 
determining potential future trends (Angeles et al. 2007, p. 556), the 
lack of fine-scale data in Puerto Rico's mountainous regions is 
especially troublesome, as variations in climate with elevation over 
short horizontal distances cannot be captured by existing climate 
models, especially in predictions of extreme events (Meehl et al. 2007, 
p. 477).
Human-Induced Fires
    Fires are not part of the natural processes for subtropical and 
moist forests in Puerto Rico (Santiago-Garcia et al. 2008, p. 604). In 
fact, M[eacute]ndez-Tejeda et al. (2015, p. 363) concluded that the 
majority of forests fires in Puerto Rico are produced by human actions. 
However, as annual rainfall decreases over time in the Caribbean 
region, longer periods of drought are expected in the future (Breshears 
et al. 2005, pp. 146-147; Larsen 2000, pp. 510-512). In 2000, Flannigan 
et al.

[[Page 58683]]

(2000, pp. 225-226) projected an increase of the global fire occurrence 
over the next century due to climate change. In Puerto Rico, historical 
evidence suggests fire frequency is increasing (Burney et al. 1994, p. 
277; Robbins et al. 2008, pp. 530-531). Moreover, the interactions 
between climate warming and drying, and increased human development, 
are considered to have the potential to increase the effects of fires 
(Robbins et al. 2008, pp. 530-531).
    In EYNF, CCF, and adjacent lands to these forests, fires are not 
considered common. The tropical rain and moist forest conditions of 
EYNF and CCF (i.e., average annual rainfall of 304.8 cm (120 in) or 
more) and the very high humidity during most of the year are not 
conditions conducive to fires as they are in the dry, temperate 
climates encountered in other regions. The last fire incident in EYNF, 
recorded in 1994, was categorized as a ``minimal fire'' that was 
quickly controlled by USFS staff (USFS 2015, no page number). In the 
CCF area, fires are considered human-induced and occur in a low 
frequency along the road PR-184 (Monsegur 2015, pers. comm.). Although 
the road-side fires are considered minimal, they have the potential to 
extend to forested lands within CCF and adjacent private lands 
affecting suitable elfin-woods warbler habitat.
    In the Maricao area (i.e., Municipalities of Sabana Grande and San 
Germ[aacute]n), fires occur more frequently on the southern dry slopes 
of MCF and adjacent private lands, particularly during the dry season 
(Avila 2014, pers. comm.). Human-induced fires modify the landscape and 
ecological conditions of the habitat by promoting growth of nonnative 
trees and grasses (Brandeis and Woodall 2008, p. 557). These landscape 
modifications may reduce the quality and quantity of potential elfin-
woods warbler habitat. Moreover, these fires alter the habitat, 
decreasing the ability of the species to disperse to other forested 
habitats. Although the primary habitat for the species in MCF (i.e., 
Podocarpus forest) (Gonz[aacute]lez 2008, pp. 20-21) is not prone to 
fire disturbance because it is located on the highest peaks within the 
lower montane wet forest life zone, suitable habitat at lower 
elevations might be in danger if these fires extend to forested lands 
within the forest or private lands. Severe fires in moist tropical 
forests have the potential to alter microclimates, allowing atypical 
forest species to invade, increasing the chance of recurrent fires 
(Sherman et al. 2008, p. 536).
    Based on the above information, other natural or manmade factors, 
such as hurricanes, climate change, and human-induced fires, are 
considered threats to the elfin-woods warbler.
Conservation Efforts To Reduce Other Natural or Manmade Factors 
Affecting the Continued Existence of the Species
    As discussed under Factor A above, a CCA was signed in 2014 by the 
Service, USFS, and PRDNER to implement strategic conservation actions. 
In the context of Factor E, these actions include the development and 
implementation of programmatic reforestation and habitat enhancement 
efforts within areas degraded by hurricanes to improve the recovery of 
the elfin-woods warbler within EYNF and MCF (Service 2014, pp. 18-19). 
Additionally, the CCA will help develop and design studies to gather 
information on the elfin-woods warbler (e.g., habitat needs, habitat 
use, movement and activity patterns, responses to biotic and abiotic 
factors, and genetic variation) in order to better design and implement 
conservation strategies for the recovery of the species.
Summary of Factor E
    Based on the information available and limited distribution of the 
elfin-woods warbler, we believe that this species is currently 
threatened by natural or manmade factors such as hurricanes and human-
induced fire. Climate change may exacerbate these threats by increasing 
intensity and frequency of hurricanes and environmental effects, 
although information is lacking on the specific extent of these 
effects. Thus, we consider Factor E to be a threat to this species.

Proposed Determination

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to elfin-woods warbler. Current available information indicates that 
the elfin-woods warbler has a limited distribution, with only two known 
populations occurring within EYNF and MCF, including the private lands 
adjacent to MCF, and at least one extirpated population from CCF. As 
discussed in the Summary of Factors Affecting the Species section of 
this proposed rule, threats to the elfin-woods warbler include loss, 
fragmentation, and degradation of habitat on private lands adjacent to 
MCF (Factor A). Some of these lands are subjected to habitat 
modification caused by unsustainable agricultural practices (i.e., sun-
grown coffee plantations), small residential development, and livestock 
related activities. Moreover, the increase of urban development on 
private lands adjacent to EYNF and CCF has also negatively affected 
suitable elfin-woods warbler habitat around these forests. The 
activities result in the elimination of native forest, thus reducing 
the suitable habitat available and the habitat value for the elfin-
woods warbler.
    Other natural or manmade factors (i.e., hurricanes, climate change, 
human-induced fires; Factor E) also have been identified as threats to 
the species. Elfin-woods warblers could experience local extinction as 
a result of catastrophic weather events such as hurricanes. While the 
species appears to have the ability to temporarily migrate to 
undisturbed areas and survive in MCF, such dispersal ability has not 
been documented at EYNF. Having two known elfin-woods warbler 
populations that are geographically separate may benefit the species to 
some degree, as it is unlikely that the same hurricane would affect 
both EYNF and MCF. However, the fact that there are only two known 
remaining populations makes the species more vulnerable to extinction 
if one is lost due to a catastrophic weather event.
    Climate change also is expected to alter the structure and 
distribution of the habitat used by the elfin-woods warbler, which may 
be particularly susceptible because of the limited distribution and 
specific forest types used by the species. Available information 
indicates that while continued change is expected, the magnitude and 
rate of that change is currently unknown. Therefore, the immediate 
impact from climate change on the elfin-woods warbler is uncertain.
    Human-induced fires have been reported in the Maricao area mostly 
within the lower southern slopes of the MCF and adjacent private lands, 
particularly during the dry season, and in the CCF area in a low 
frequency along the road PR-184. These fires can modify the landscape 
and ecological conditions, and reduce the quality and quantity of 
potential elfin-woods warbler habitat. Habitat disturbance caused by 
human-induced fires may also affect the ability of the species to 
disperse to other forested habitats. However, in MCF, the areas that 
are more prone to human-induced fires are not the primary habitat for 
the species, which is the Podocarpus forest. This forest type is not 
prone to fire disturbance because it is located on highest peaks within 
the lower montane wet forest life zone. Although the primary habitat 
for the species in MCF, EYNF, and CCF is not prone to fire disturbance, 
potential suitable habitat at

[[Page 58684]]

lower elevations might be in danger if these fires extend to forested 
lands within the forests or private lands.
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as any species ``that is likely to 
become endangered throughout all or a significant portion of its range 
within the foreseeable future.'' We find that the elfin-woods warbler 
is not presently in danger of extinction throughout its entire range 
based on the low to moderate severity and non-immediacy of threats 
currently impacting the species. The available information indicates 
that elfin-woods warbler populations appear to be stable in MCF and 
that there are no immediate threats precipitating a demographic decline 
of the elfin-woods warbler in that forest. In Maricao, the species has 
been reported adjacent to the Commonwealth forest in shade-grown coffee 
plantations, demonstrating that the species may tolerate some degree of 
habitat disturbance. At EYNF, the most current information reported a 
declining trend of the elfin-woods warbler population, mainly 
attributed to hurricanes striking that forest. However, there are no 
specific studies corroborating that hurricanes are in fact the main 
cause of elfin-woods warbler population declines at EYNF and other 
factors may be influencing the decline (e.g., population low densities 
and patchy spatial arrangement). Although the species appears to be 
stable at the MCF, it may be declining at EYNF and extirpated from CCF. 
The cumulative effects of habitat modification by human actions (e.g., 
unsustainable agricultural practices) and natural events such as 
hurricanes would make the two known populations more vulnerable to 
extinction due to their restricted distribution, limited population 
numbers, and specific ecological requirements. Therefore, on the basis 
of the best available scientific and commercial information, we propose 
listing the elfin-woods warbler as threatened in accordance with 
sections 3(20) and 4(a)(1) of the Act. We find that an endangered 
species status is not appropriate for elfin-woods warbler because the 
species is not currently in imminent danger of extinction.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. Because we have determined that 
elfin-woods warbler is threatened throughout all of its range, no 
portion of its range can be ``significant'' for purposes of the 
definitions of ``endangered species'' and ``threatened species.'' See 
the Final Policy on Interpretation of the Phrase ``Significant Portion 
of Its Range'' in the Endangered Species Act's Definitions of 
``Endangered Species'' and ``Threatened Species'' (79 FR 37577; July 1, 
2014).

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness, and 
conservation by Federal, State, Tribal, and local agencies; private 
organizations; and individuals. The Act encourages cooperation with the 
States and other countries and calls for recovery actions to be carried 
out for listed species. The protection required by Federal agencies and 
the prohibitions against certain activities are discussed, in part, 
below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act calls for the Service to develop 
and implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed and preparation of a draft and final 
recovery plan. The recovery outline guides the immediate implementation 
of urgent recovery actions and describes the process to be used to 
develop a recovery plan. The plan may be revised to address continuing 
or new threats to the species, as new substantive information becomes 
available. The recovery plan also identifies recovery criteria for 
review of when a species may be ready for reclassification from 
endangered to threatened or for delisting and methods for monitoring 
recovery progress. Recovery plans also establish a framework for 
agencies to coordinate their recovery efforts and provide estimates of 
the cost of implementing recovery tasks. Recovery teams (composed of 
species experts, Federal and State agencies, nongovernmental 
organizations, and stakeholders) are often established to develop 
recovery plans. If this species is listed, the recovery outline, draft 
recovery plan, and the final recovery plan will be made available on 
our Web site (https://www.fws.gov/endangered), or from our Caribbean 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands. 
If this species is listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. In addition, 
pursuant to section 6 of the Act, the Commonwealth of Puerto Rico would 
be eligible for Federal funds to implement management actions that 
promote the protection or recovery of the elfin-woods warbler. 
Information on our grant programs that are available to aid species 
recovery can be found at: https://www.fws.gov/grants.
    Although the elfin-woods warbler is only proposed for listing as 
threatened under the Act at this time, please let us know if you are 
interested in participating in conservation efforts for this species. 
Additionally, we invite you to submit any new information on this 
species whenever it becomes available and any information you may have 
for conservation planning purposes (see FOR FURTHER INFORMATION 
CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as an 
endangered or threatened species and with respect to its critical 
habitat, if any is designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7 (a)(1) of the Act directs all Federal agencies to 
``utilize their authorities in furtherance of the

[[Page 58685]]

purposes of the Act by carrying out programs for the conservation of'' 
endangered and threatened species. Section 7(a)(4) of the Act requires 
Federal agencies to confer with the Service on any action that is 
likely to jeopardize the continued existence of a species proposed for 
listing or result in destruction or adverse modification of proposed 
critical habitat. If a species is listed subsequently, section 7(a)(2) 
of the Act requires Federal agencies to ensure that activities they 
authorize, fund, or carry out are not likely to jeopardize the 
continued existence of the species or destroy or adversely modify its 
critical habitat. If a Federal action may affect a listed species or 
its critical habitat, the responsible Federal agency must enter into 
consultation with the Service.
    Federal agency actions within the species' habitat that may require 
conference or consultation or both as described in the preceding 
paragraph include management and any other landscape-altering 
activities on Federal lands administered by the USFS; issuance of 
section 404 Clean Water Act (33 U.S.C. 1251 et seq.) permits by the 
U.S. Army Corps of Engineers; and construction and maintenance of roads 
or highways by the Federal Highway Administration.

Proposed 4(d) Rule

    Under section 4(d) of the Act, the Service has discretion to issue 
regulations that we find necessary and advisable to provide for the 
conservation of threatened wildlife. We may also prohibit by 
regulation, with respect to threatened wildlife, any act prohibited by 
section 9(a)(1) of the Act for endangered wildlife. 50 CFR 17.31(a) 
applies all the general prohibitions for endangered wildlife set forth 
at 50 CFR 17.21 to threatened wildlife; 50 CFR 17.31(c) states that 
whenever a 4(d) rule applies to a threatened species, the provisions of 
17.31(a) do not apply to that species. Permit provisions for threatened 
species are set forth at 50 CFR 17.32.
    Some activities that would normally be prohibited under 50 CFR 
17.31 and 17.32 will contribute to the conservation of the elfin-woods 
warbler because habitats within some of the physically degraded private 
lands adjacent to elfin-woods warbler existing populations must be 
improved before they are suitable for the species. Therefore, for the 
elfin-woods warbler, the Service has determined that species-specific 
exceptions authorized under section 4(d) of the Act may be appropriate 
to promote the conservation of this species. Like the proposed listing 
rule, this proposal will not be finalized until we have reviewed 
comments from the public and peer reviewers.
    As discussed above in the Summary of Factors Affecting the Species 
section of this proposed listing rule, threats to the species include 
loss, fragmentation, and degradation of habitat due to unsustainable 
agricultural practices and land use requiring vegetation clearance. 
Agricultural practices occurring on private lands adjacent to MCF, 
especially those involving habitat modification (e.g., deforestation 
and conversion of shade-grown coffee to sun-grown coffee plantations), 
can result in vegetation removal and habitat alteration, thereby 
degrading habitats used by elfin-woods warbler for feeding, sheltering, 
and reproduction.
    The private lands surrounding MCF are considered the most active 
coffee production lands in Puerto Rico. Sun-grown coffee plantations 
adjacent to MCF were converted several decades ago, resulting in the 
elimination of native forest overstory, reducing the habitat value for 
wildlife, including the elfin-woods warbler. Although the majority of 
the coffee-related agricultural lands were converted to sun-grown 
coffee plantations, several parcels of land surrounding MCF are 
currently part of a multi-agency habitat restoration initiative in 
southwestern Puerto Rico implemented by the Service and NRCS since 
2010, through the PFW, CP, and U.S. Department of Agriculture Farm Bill 
Programs. Activities that improve or restore physical habitat quality, 
such as the conversion of sun-grown coffee to shade-grown coffee, 
reforestation with native trees, riparian buffering, and forested 
habitat enhancement (i.e., exotic species removal, and native tree 
planting), would have a positive effect on elfin-woods warbler 
populations and would provide an overall conservation benefit to the 
species. The NRCS conservation practices promoted under this initiative 
are the Multi-Story Cropping (Practice 379) and Tree/Shrub 
Establishment (Practice 612) (USFWS 2011). The Multi-Story Cropping 
practice promotes the establishment of stands of trees or shrubs that 
are managed as overstory with an understory of woody and/or non-woody 
plants that are grown for a variety of products. The purpose of this 
practice is to improve crop diversity by growing mixed but compatible 
crops having different heights in the same area. This will improve soil 
quality, reduce erosion, enhance degraded areas, and provide habitat 
for wildlife species such as the elfin-woods warbler. The Tree/Shrub 
Establishment Practice promotes the establishment of woody plants by 
planting seedlings or cuttings, direct seeding, or natural 
regeneration. The purpose is to promote forest products such as timber, 
wildlife habitat, long-term erosion control, and improvement of water 
quality, and to improve or restore natural diversity.

Provisions of the Proposed 4(d) Rule

    Under this proposed 4(d) rule, all of the prohibitions set forth at 
50 CFR 17.31 and 17.32 would apply to the elfin-woods warbler, except 
that incidental take caused by the following activities conducted 
within habitats currently occupied by the elfin-woods warbler on 
private, Commonwealth, and Federal lands would not be prohibited, 
provided those activities (1) abide by the conservation measures in the 
rule, and (2) are conducted in accordance with applicable Commonwealth, 
Federal, and local laws and regulations:
    (1) The conversion of sun-grown coffee to shade-grown coffee 
plantations by the restoration and maintenance (i.e., removal of 
invasive, exotic, and feral species; shade and coffee tree seasonal 
pruning; shade and coffee tree planting and replacement; coffee bean 
harvest by hands-on methods; and the use of standard pest control 
methods and fertilizers within the plantations) of shade-grown coffee 
plantations and native forests associated with this type of crop. To 
minimize disturbance to elfin-woods warbler, shade and coffee tree 
seasonal pruning must be conducted outside the peak of the elfin-woods 
warbler's breeding season (July 1 through February 28). The Service 
considers the use of pest control methods (e.g., pesticides, 
herbicides) and fertilizers ``standard'' when it is used only twice a 
year during the establishment period of shade and coffee trees (i.e., 
the first 2 years). During this period, the structure of the 
agroforestry system is not mature enough to sustain the occurrence of 
elfin-woods warblers within these areas.
    Once the shade-grown coffee system reaches its functionality and 
structure (i.e., 3 to 4 years), little or no chemical fertilizers, 
herbicides, or pesticides are required, their use would be restricted 
under the proposed 4(d) rule. This is the time period when the shade-
grown coffee system is mature enough to support the presence of 
wildlife species. Researchers have found that the number of species of 
birds in coffee plantations with structurally and floristically diverse 
canopies is similar to the number of species in natural forest habitat 
and is higher than other agricultural landscapes without trees 
(Perfecto et al. 1996, pp. 603-605).

[[Page 58686]]

    The restoration of agricultural lands due to the planting of native 
trees to provide shade to coffee trees or by selective removal of 
exotic species creates physically stable and suitable habitats for the 
elfin-woods warbler. Moreover, the cultivation of shade-grown coffee 
has many other ecological and human-health benefits such as the 
reduction of soil erosion, moderation of soil temperatures, and reduced 
need for fertilizers and pesticides (Borkhataria et al. 2012, p.168). 
Therefore, restoration, conservation, and protection of shade-grown 
coffee plantations would provide suitable habitat for the feeding, 
sheltering, and reproduction activities of this species and may provide 
habitat to promote the elfin-woods warblers' dispersal and 
recolonization of lands adjacent to the existing populations.
    (2) Riparian buffer establishment through the planting of native 
vegetation and removal of exotic species may improve the habitat 
conditions of Gallery forests along the sub-watersheds associated with 
lands adjacent to the elfin-woods warbler's existing populations. 
Gallery forests serve as biological corridors that maintain 
connectivity between forested lands and associated agricultural lands, 
reducing the fragmentation in the landscape.
    (3) Reforestation and forested habitat enhancement projects within 
secondary forests (i.e., young and mature) that promote the 
establishment or improvement of habitat conditions for the species by 
the planting of native trees, selective removal of native and exotic 
trees, seasonal pruning of native and exotic trees, or a combination of 
these.
    The intent of these exceptions is to provide incentive for 
landowners to carry out these activities in a manner which we believe 
will provide benefits to the species such as (1) maintaining 
connectivity of suitable elfin-woods warbler habitats, allowing for 
dispersal between forested and agricultural lands; (2) minimizing 
habitat disturbance by conducting certain activities outside the peak 
of the elfin-woods warbler's breeding season (i.e., July 1 to February 
28); (3) maximizing the amount of habitat that is available for the 
species; and (4) improving habitat quality. While these activities may 
cause some temporary disturbance to the elfin-woods warbler or its 
habitat, we do not expect these activities to adversely affect the 
species' conservation efforts. In fact, we expect they will have a net 
beneficial effect on the species.
    Based on the rationale above, the provisions included in this 
proposed rule authorized under section 4(d) of the Act are necessary 
and advisable to provide for the conservation of the elfin-woods 
warbler. Nothing in this proposed 4(d) rule would change in any way the 
recovery planning provisions of section 4(f) of the Act, the 
consultation requirements under section 7 of the Act, or the ability of 
the Service to enter into partnerships for the management and 
protection of the elfin-woods warbler.
    We may issue permits to carry out otherwise prohibited activities 
involving threatened wildlife under certain circumstances. Regulations 
governing permits are codified at 50 CFR 17.32. With regard to 
threatened wildlife, a permit may be issued for the following purposes: 
For scientific purposes, to enhance the propagation or survival of the 
species, economic hardship, zoological exhibition, educational 
purposes, and for incidental take in connection with otherwise lawful 
activities. There are also certain statutory exemptions from the 
prohibitions, which are found in sections 9 and 10 of the Act.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act (for this species, those 
section 9 prohibitions that would be adopted through the proposed 4(d) 
rule). The intent of this policy is to increase public awareness of the 
effect of a proposed listing on proposed and ongoing activities within 
the range of species proposed for listing. Based on the best available 
information, the following actions are unlikely to result in a 
violation of section 9, if these activities are carried out in 
accordance with existing regulations and permit requirements. This list 
is not comprehensive:
    (1) Activities authorized, funded, or carried out by Federal or 
Commonwealth agencies (e.g., expansion or construction of communication 
facilities; expansion of recreational facilities; pipeline 
construction; bridge construction; road rehabilitation and maintenance; 
expansion, construction, or maintenance of aqueduct facilities; habitat 
management; Federal and Commonwealth trust species reintroductions; 
trail maintenance; camping areas maintenance; research, repair, and 
restoration of landslides; etc.), when such activities are conducted in 
accordance with the consultation and planning requirements for listed 
species under section 7 of the Act; and
    (2) Agricultural and silviculture practices implemented within 
existing agricultural lands (i.e., degraded habitat not suitable for 
the species) other than sun to shade-grown coffee conversion and 
maintenance, including herbicide, pesticide, and fertilizer use outside 
of coffee plantations, which are carried out in accordance with any 
Commonwealth and Federal existing regulations, permit and label 
requirements, and best management practices.
    We believe the following activities may potentially result in a 
violation of section 9 the Act. This list is not comprehensive:
    (1) Unauthorized collecting or handling of the species;
    (2) Destruction/alteration/fragmentation of habitat essential to 
fulfilling the lifecycle of the species; and
    (3) Introduction of nonnative species that compete with or prey 
upon the elfin-woods warbler.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Caribbean 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Critical Habitat
    Section 3(5)(A) of the Act defines critical habitat as (i) the 
specific areas within the geographical area occupied by the species, at 
the time it is listed . . . on which are found those physical or 
biological features (I) Essential to the conservation of the species 
and (II) which may require special management considerations or 
protection; and (ii) specific areas outside the geographical area 
occupied by the species at the time it is listed . . . upon a 
determination by the Secretary that such areas are essential for the 
conservation of the species. Section 3(3) of the Act (16 U.S.C. 
1532(3)) defines the terms ``conserve,'' ``conserving,'' and 
``conservation'' to mean to use and the use of all methods and 
procedures which are necessary to bring any endangered species or 
threatened species to the point at which the measures provided pursuant 
to this chapter Act are no longer necessary.
    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12), require that, to the maximum extent 
prudent and determinable, the Secretary shall designate critical 
habitat at the time the species is determined to be an endangered or 
threatened species. Our regulations (50 CFR 424.12(a)(1)) state that 
the designation of critical habitat is not prudent when one or both of 
the following situations exist:
    (1) The species is threatened by taking or other human activity, 
and

[[Page 58687]]

identification of critical habitat can be expected to increase the 
degree of threat to the species, or
    (2) Such designation of critical habitat would not be beneficial to 
the species.
    As discussed under Factor B above, there is currently no imminent 
threat of take attributed to collection or vandalism for this species, 
and identification and mapping of critical habitat is not expected to 
initiate any such threat. Therefore, in the absence of finding that the 
designation of critical habitat would increase threats to a species, if 
there are any benefits to a critical habitat designation, we must find 
that designation is prudent. Here, the potential benefits of 
designation include: (1) Triggering consultation under section 7 of the 
Act, in new areas for actions in which there may be a Federal nexus 
where it would not otherwise occur because, for example, it is 
unoccupied; (2) focusing conservation activities on the most essential 
features and areas; (3) providing educational benefits to State or 
county governments or private entities; and (4) reducing the potential 
for people to cause inadvertent harm to the species.
    Because we have determined that the designation of critical habitat 
will not likely increase the degree of threat to the species and may 
provide some measure of benefit, we determine that designation of 
critical habitat is prudent for the elfin-woods warbler.
    Our regulations (50 CFR 424.12(a)(2)) further state that critical 
habitat is not determinable when one or both of the following 
situations exists: (1) Information sufficient to perform required 
analysis of the impacts of the designation is lacking; or (2) the 
biological needs of the species are not sufficiently well known to 
permit identification of an area as critical habitat. On the basis of a 
review of available information, we find that critical habitat for 
elfin-woods warbler is not determinable because the specific 
information sufficient to perform the required analysis of the impacts 
of the designation is currently lacking.

Required Determinations

Clarity of the Rulemaking

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in the ADDRESSES section. To 
better help us revise the rule, your comments should be as specific as 
possible. For example, you should tell us the numbers of the sections 
or paragraphs that are unclearly written, which sections or sentences 
are too long, the sections where you feel lists or tables would be 
useful, etc.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act, need not be prepared in connection with 
listing a species as an endangered or threatened species under the 
Endangered Species Act. We published a notice outlining our reasons for 
this determination in the Federal Register on October 25, 1983 (48 FR 
49244).

References Cited

    A complete list of references cited in this rulemaking is available 
on the Internet at https://www.regulations.gov and upon request from the 
Caribbean Ecological Services Field Office (see FOR FURTHER INFORMATION 
CONTACT).

Authors

    The primary authors of this proposed rule are the staff members of 
the Caribbean Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17--[AMENDED]

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 4201-4245, 
unless otherwise noted.

0
2. Amend Sec.  17.11(h) by adding an entry for ``Warbler, Elfin-woods'' 
to the List of Endangered and Threatened Wildlife in alphabetical order 
under BIRDS to read as set forth below:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                        Species                                                    Vertebrate
--------------------------------------------------------                        population where                                  Critical     Special
                                                            Historic range       endangered or         Status      When listed    habitat       rules
           Common name                Scientific name                              threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
              Birds
 
                                                                      * * * * * * *
Warbler, elfin-woods.............  Setophaga angelae...  U.S.A. (PR)........  Entire.............  T               ...........           NA     17.41(e)
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
0
3. Amend Sec.  17.41 by adding paragraph (e) to read as follows:


Sec.  17.41  Special rules--birds.

* * * * *
    (e) Elfin-woods warbler (Setophaga angelae). (1) Prohibitions. 
Except as noted in paragraph (e)(2) of this section, all prohibitions 
and provisions of 50 CFR 17.31 and 17.32 apply to the elfin-woods 
warbler.
    (2) Exemptions from prohibitions. Incidental take of the elfin-
woods warbler will not be considered a violation of section 9 of the 
Act if the take results from any of the following when conducted within 
habitats currently occupied by elfin-woods

[[Page 58688]]

warbler provided these activities abide by the conservation measures 
set forth in this paragraph and are conducted in accordance with 
applicable State, Federal, and local laws and regulations:
    (i) The conversion of sun-grown coffee to shade-grown coffee 
plantations by the restoration and maintenance (i.e., removal of 
invasive, exotic, and feral species; shade and coffee tree seasonal 
pruning; shade and coffee tree planting and replacement; coffee bean 
harvest by hands-on methods; and the use of standard pest control 
methods and fertilizers within the plantations) of shade-grown coffee 
plantations and native forests associated with this type of crop. To 
minimize disturbance to elfin-woods warbler, shade and coffee tree 
seasonal pruning must be conducted outside the peak of the elfin-woods 
warbler's breeding season (i.e., July through February). The Service 
considers the use of pest control methods (e.g., pesticides, 
herbicides) and fertilizers ``standard'' when it is used only twice a 
year during the establishment period of shade and coffee trees (i.e., 
the first 2 years). Once the shade-grown coffee system reaches its 
functionality and structure (i.e., 3 to 4 years), little or no chemical 
fertilizers, herbicides, or pesticides may be used.
    (ii) Riparian buffer establishment though the planting of native 
vegetation and selective removal of exotic species.
    (iii) Reforestation and forested habitat enhancement projects 
within secondary forests (i.e., young and mature) that promote the 
establishment or improvement of habitat conditions for the species by 
the planting of native trees, selective removal of native and exotic 
trees, seasonal pruning of native and exotic trees, or a combination of 
these.
* * * * *

    Dated: September 17, 2015.
Stephen Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-24775 Filed 9-29-15; 8:45 am]
 BILLING CODE 4310-55-P