Endangered and Threatened Wildlife and Plants; Listing the Medium Tree Finch (Camarhynchus pauper) as Endangered Throughout Its Range, 74434-74445 [E8-28998]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 73, Number 236 (Monday, December 8, 2008)]
[Proposed Rules]
[Pages 74434-74445]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-28998]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R9-IA-2008-0108; 96100-1671-0000-B6]
RIN 1018-AW01


Endangered and Threatened Wildlife and Plants; Listing the Medium 
Tree Finch (Camarhynchus pauper) as Endangered Throughout Its Range

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the medium tree finch (Camarhynchus pauper) as endangered under 
the Endangered Species Act of 1973, as amended (Act). This proposal, if 
made final, would extend the Act's protection to this species. The 
Service seeks data and comments from the public on this proposed rule.

DATES: We will accept comments received or postmarked on or before 
February 6, 2009. We must receive requests for public hearings, in 
writing, at the address shown in the FOR FURTHER INFORMATION CONTACT 
section by January 22, 2009.

ADDRESSES: You may submit comments by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the instructions for submitting comments.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R9-IA-2008-0108; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, 
Suite 222; Arlington, VA 22203.
We will not accept comments by e-mail or fax. We will post all comments 
on https://www.regulations.gov. This generally means that we will post 
any personal information you provide us (see the Public Comments 
section below for more information).

FOR FURTHER INFORMATION CONTACT: Monica A. Horton, Division of 
Scientific Authority, U.S. Fish and Wildlife Service, 4401 N. Fairfax 
Drive, Room 110, Arlington, VA 22203; telephone 703-358-1708; facsimile 
703-358-2276. If you use a telecommunications device for the deaf 
(TDD), call the Federal Information Relay Service (FIRS) at 800-877-
8339.

SUPPLEMENTARY INFORMATION:

Public Comments

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, we request 
comments or suggestions on this proposed rule. We particularly seek 
comments concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species and regulations that may 
be addressing those threats.
    (2) Additional information concerning the range, distribution, and 
population size of this species, including the locations of any 
additional populations of this species.
    (3) Any information on the biological or ecological requirements of 
the species.
    (4) Current or planned activities in the areas occupied by the 
species and possible impacts of these activities on this species.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We will not 
consider comments sent by e-mail or fax or to an address not listed in 
the ADDRESSES section.
    If you submit a comment via https://www.regulations.gov, your entire 
comment--including any personal identifying information--will be posted 
on the Web site. If you submit a hardcopy comment 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 comments on https://www.regulations.gov.
    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, Division of Scientific Authority, 4401 N. Fairfax 
Drive, Room 110, Arlington, VA 22203; telephone 703-358-1708.

Background

    Section 4(b)(3)(A) of the Act requires us to make a finding (known 
as a ``90-day finding'') on whether a petition to add a species to, 
remove a species from, or reclassify a species on the Federal List of 
Endangered and Threatened Wildlife and Plants has presented substantial 
information indicating that the requested action may be warranted. To 
the maximum extent practicable, the finding must be made within 90 days 
following receipt of the petition and published promptly in the Federal 
Register. If we find that the petition has presented substantial 
information indicating that the requested action may be warranted (a 
positive finding), section 4(b)(3)(A) of the Act requires us to 
commence a status review of the species if one has not already been 
initiated under our internal candidate assessment process. In addition, 
section 4(b)(3)(B) of the Act requires us to make a finding within 12 
months following receipt of the petition on whether the requested 
action is warranted, not warranted, or warranted but precluded by 
higher priority listing actions (this finding is referred to as the 
``12-month finding''). Section 4(b)(3)(C) of the Act requires that a 
finding of warranted but precluded for petition species should be 
treated as having been resubmitted on the date of the warranted but 
precluded finding, and is, therefore, subject to a new finding within 1 
year and subsequently thereafter until we take action on a proposal to 
list or withdraw our original finding. The Service publishes an annual 
notice of resubmitted petition findings (annual notice) for all foreign 
species for which listings were previously found to be warranted but 
precluded.

Previous Federal Actions

    On May 6, 1991, we received a petition (hereafter referred to as 
the 1991 petition) from the International Council for Bird Preservation 
(ICBP) to add 53 species of foreign birds to the List of Endangered and 
Threatened Wildlife (50 CFR 17.11(h)), including the medium tree finch, 
which is the subject of this proposed rule. In response to the 1991 
petition, we published a positive 90-day finding on December 16, 1991 
(56 FR 65207), for all 53 species, and announced the initiation of a 
status review. On March 28, 1994 (59 FR 14496), we published a 12-month 
finding on the 1991 petition, along with a proposed rule to list 30 
African birds under the Act (16 U.S.C. 1531 et seq.). In that document, 
we proposed listing 15 of the 53 bird species included in the 1991 
petition, and announced our finding that listing the remaining 38 
species from the 1991 petition, including the medium tree finch, was 
warranted but precluded because of other listing activity.
    On May 21, 2004 (69 FR 29354) and April 23, 2007 (72 FR 20184), we 
published in the Federal Register notices announcing our annual 
petition findings for foreign species. In those

[[Page 74435]]

notices, we made warranted but precluded findings for all outstanding 
foreign species from the 1991 petition, including the medium tree 
finch, which is the subject of this proposed rule.
    Per the Service's listing priority guidelines (September 21, 1983; 
48 FR 43098), our 2007 annual notice of review (ANOR) (April 23, 2007; 
72 FR 20184) identified the listing priority numbers (LPNs) (ranging 
from 1 to 12) for all outstanding foreign species, including the medium 
tree finch, which was designated with an LPN of 11. The medium tree 
finch does not represent a monotypic genus. As reported in the 2007 
ANOR, the magnitude of threat to the species was moderate, as the 
species was common in the forested highlands and its habitat had not 
been highly degraded. The immediacy of threat was not imminent because 
the species' habitat is protected by the area's National Park and World 
Heritage Site status.
    On January 23, 2008, the United States District Court ordered the 
Service to propose listing rules for five foreign bird species, actions 
which had been previously determined to be warranted but precluded: 
Andean flamingo (Phoenicoparrus andinus), black-breasted puffleg 
(Eriocnemis nigrivestis), Chilean woodstar (Eulidia yarrellii), medium 
tree finch (Camarhynchus pauper), and St. Lucia forest thrush 
(Cichlherminia lherminieri sanctaeluciae). The court ordered the 
Service to issue proposed listing rules for these species by the end of 
2008.
    On July 29, 2008 (73 FR 44062), we published in the Federal 
Register a notice announcing our annual petition findings for foreign 
species. In that notice, we announced that proposing 30 taxa for 
listing under the Act is warranted. In order to comply with the recent 
court order, the medium tree finch was included as one of the 30 taxa 
for which listing is warranted.

Species Information

    The medium tree finch (Camarhynchus pauper) is endemic to the 
island of Floreana in the Galapagos Islands, Ecuador (BirdLife 
International 2008; Harris 1982, p. 150; Sibley and Monroe 1990, p. 
771). It is one of the 14 species of Darwin's finches, collectively 
named in recognition of Charles Darwin's work on the theory of 
evolution (Grant 1986, p. 6), and is approximately 12.5 centimeters 
(cm) (5 inches (in)) in length (BirdLife International 2008; Harris 
1982, p. 150). Medium tree finches have wings and tails that are short 
and rounded, and often hold their tail slightly cocked in a wren-like 
manner (Jackson 1985, p. 188). Males have a black head, neck, and upper 
breast (Fitter et al. 2000, p. 78; Harris 1982, p. 150; Jackson 1985, 
p. 188), and an underside that is gray-brown, and white or yellowish in 
color (BirdLife International 2008). Their tail and back is olive green 
(Fitter et al. 2000, p. 78). Females have a head that is more gray-
brown (BirdLife International 2008), and a body that is generally 
olive-green above and pale yellowish below (Fitter et al. 2000, p. 78). 
It is similar to the large and small tree finches of the same genus, 
but differs from the large tree finch (Camarhynchus psittacula) 
primarily due to its significantly smaller and less parrot-like beak, 
and from the small tree finch (Camarhynchus parvulus) because of its 
larger beak (BirdLife International 2008; Harris 1982, p. 150). It is 
also known as the Charles tree finch, the Santa Maria tree finch, and 
the Floreana tree finch (Sibley and Monroe 1990, p. 771), due to the 
fact that the island of Floreana is also referred to as Charles Island 
or Santa Maroa Island, the official Spanish name of the island (Grant 
1986, Appendix; Harris 1973, p. 265). The species is locally known as 
``Pinz[oacute]n Mediano de [Aacute]rbol'' (Castro and Phillips 1996, p. 
130). The species was first taxonomically described by Ridgeway in 1890 
(Sibley and Monroe 1990, p. 771).

Habitat and Life History

    Floreana, one of the 19 principal islands that make up the 
Galapagos archipelago (McEwen 1988, p. 234), is 173 square kilometers 
(km2) (67 square miles (mi2)) in area, and has a 
maximum elevation of 640 meters (m) (2,100 feet (ft)) (Swash and Still 
2005, p. 10).
    The medium tree finch mainly occurs in the moist highland forests 
(i.e., the Scalesia zone, named for the dominant plants, Scalesia spp., 
found in this zone) (Christensen and Kleindorfer 2008, in preparation; 
Stewart 2006, p. 193), primarily above 300 m (984 ft) (Castro and 
Phillips 1996, p. 130). The Scalesia zone begins at an altitude between 
180 (Wiggins and Porter 1971, p. 22) and 200 m (591-656 ft), and ends 
at approximately 600 m (1,968 ft) (Stephenson 2000, p. 34), and is the 
first of the moist zones found on the Galapagos Islands (Fitter et al. 
2000, p. 137).
    On Floreana, the Scalesia zone is a lush evergreen cloud forest 
dominated by Scalesia pedunculata (daisy tree), the largest of the 20 
species of Scalesia found in the Galapagos (Fitter et al. 2000, p. 137; 
Jackson 1985, p. 95). Scalesia form dense stands (Fitter et al. 2000, 
p. 137), with S. pedunculata frequently reaching 15 m (49 ft) in 
height, and can reach up to 20 m (66 ft) or more given good 
environmental conditions (Fitter et al. 2000, p. 137; Wiggins and 
Porter 1971, p. 22).
    The Scalesia zone on Floreana is also dominated by the endemic 
trees Croton scouleri (Gal[aacute]pagos croton) and Zanthoxylum fagara 
(lime prickly-ash), with other dominant plants including Phoradendron 
henslowii (mistletoe), the shrub Macraea laricifolia, and introduced 
fruit species such as Citrus limetta, Passiflora edulis, and Psidium 
guajava (Christensen and Kleindorfer 2008, in preparation). Beneath the 
top of the canopy, epiphytes (plants that live on another plant without 
causing harm to the host plant) cover trunks, branches, twigs, and even 
the leaves of some plant species (Fitter et al. 2000, p. 137; Wiggins 
and Porter 1971, p. 24). Common epiphytes found in the Scalesia zone 
are mosses, liverworts, ferns, Peperomia, bromeliads (such as 
Tillandsia), and orchids (Fitter et al. 2000, p. 137; Jackson 1985, p. 
60; Wiggins and Porter 1971, pp. 22, 24). Epiphytes are a prominent 
feature of the moist zones of the Galapagos Islands because of the 
large amount of time that clouds and mist cover the upper elevations of 
the higher islands (Fitter et al. 2000, p. 137).
    A large amount of the Scalesia zone has been destroyed on the 
inhabited islands because it is the best area for agriculture (Fitter 
et al. 2000, p. 137; Jackson 1985, p. 61). The gar[uacute]a (dense sea 
mist that sometimes blankets the highlands) keeps the area well-watered 
during the cool season (Fitter et al. 2000, p. 137; Jackson 1985, p. 
61), which makes the area ideal for agricultural use.
    Stotz et al. (1996) reported that the elevational zone in which the 
medium tree finch is most common is ``Hill Tropical,'' described as 
hills and lower slopes, between 500-900 m (1,640-2,953 ft) (pp. 121, 
262). The species reaches its minimum elevation in relatively low-
relief lowland areas and reaches its maximum elevation at 600 m (1,969 
ft) (Stotz et al. 1996, p. 262). As a result, one can infer from this 
data that the medium tree finch is predominantly found at the highest 
end of its elevational distribution, between 500 and 600 m (1,640 and 
1,969 ft).
    According to Stotz et al. (1996), the medium tree finch uses more 
than one level at which it forages within its habitat; specifically, 
they noted that it can be found foraging from the understory 
(undergrowth) to the canopy (pp. 120, 262). In addition, Bowman (1963) 
reports that Camarhynchus species spend a little less than 25 percent 
of their time foraging at the

[[Page 74436]]

ground level, while spending the majority of their time foraging above 
ground (p. 132). The medium tree finch uses its powerful tip-biting 
bill to search under twigs and foliage, probe crevices in the bark of 
trees, and cut into tough woody tissues in search of insect larvae 
(Bowman 1963, pp. 117, 125), which is its primary food source (Bowman 
1963, p. 121). The species also feeds, to a lesser extent, on seeds 
(Bowman 1963, p. 121), nectar, young buds, and leaves (Castro and 
Phillips 1996, p. 130).
    The peak breeding season for the medium tree finch is February-
April (O'Connor et al. 2008b, in preparation). The species prefers to 
nest in the tree Scalesia pedunculata (O'Connor et al. 2008b, in 
preparation), and has an average clutch size of two to four eggs 
(O'Connor et al. 2008a, in preparation). The nests of Darwin's finches 
are similar in construction from one species to another; the male 
builds a dome-shaped nest, made from twigs, grass, pieces of bark, 
lichens, feathers, and other materials, with a small, round, side 
entrance (Jackson 1985, p. 191). In a study of the nesting success of 
the small tree finch in the highlands of Santa Cruz Island in the 
Galapagos, Kleindorfer (2007) found that all nests were located 6 to 10 
m (20 to 33 ft) above the ground, on horizontal branches of Scalesia 
pedunculata, and positioned by interweaving surrounding smaller twigs 
and leaves (p. 796).

Range and Distribution

    According to BirdLife International (2008), the current range of 
the medium tree finch is estimated to be 23 km\2\ (9 mi\2\). The 
species' range encompasses the entire highland area of Floreana; 
however, the medium tree finch is restricted to fragmented forest 
patches within the highlands, which total approximately 12 km\2\ (4.5 
mi\2\) to 17 km\2\ (6.5 mi\2\) of available habitat (O'Connor et al. 
2008b, in preparation). Harris (1982) reported that the species was 
common in the highlands on Floreana and uncommon to rare on the coast 
(p. 150).
    Population numbers of this species are poorly known, with an 
indirect estimation at 1,000 to 2,499 birds in the year 2000 (BirdLife 
International 2008). Fessl et al. (2006a) reported that there were 
about 300 breeding pairs remaining on Floreana (p. 745). In a study by 
O'Connor et al. (2008b, in preparation), they compared bird abundance 
survey data from 2004 and 2008 in order to estimate the population 
density of the medium tree finch in the highlands of Floreana. Based on 
the results of their study, O'Connor et al. (2008b, in preparation) 
estimate that the total medium tree finch population currently consists 
of 860-1,220 individuals (72 birds/km\2\ (28 birds/mi\2\), calculated 
as an average over the 4 survey sites in 2008). Their study also showed 
that the population density of the species at Cerro Pajas, the largest 
patch of prime Scalesia habitat (9 km\2\ (3.5 mi\2\)), decreased from 
154 birds/km\2\ (59 birds/mi\2\) in 2004 to 60 birds/km\2\ (23 birds/
mi\2\) in 2008 (O'Connor et al. 2008b, in preparation).

Conservation Status

    The medium tree finch is identified as a ``critically endangered'' 
species under Ecuadorian law, Decree No. 3,516--Unified Text of the 
Secondary Legislation of the Ministry of Environment (ECOLEX 2003b). 
This poorly known species is considered ``Vulnerable'' by the 
International Union for Conservation of Nature (IUCN) because it has a 
very small range and is restricted to a single island where introduced 
species are considered a potential threat to the species and its 
habitat (BirdLife International 2008).
    Stotz et al. (1996) described the conservation priority for the 
medium tree finch as ``high,'' which they defined as a species that is 
``threatened,'' usually because of range or habitat restriction, and 
already showing signs of serious population decline (p. 262).

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR 424, set forth the procedures for adding species 
to the Federal Lists of Endangered and Threatened Wildlife and Plants. 
A species may be determined to be an endangered or threatened species 
due to one or more of the five factors described in section 4(a)(1) of 
the Act. The five factors are: (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; and (E) other natural or manmade 
factors affecting its continued existence.

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

    Floreana has the longest history of human habitation of any of the 
Galapagos Islands (Fitter et al. 2000, p. 207; Schofield 1989, p. 229); 
it was first settled in 1832, three years before Darwin's historic 
visit (Jackson 1985, p. 3; Stewart 2006, pp. 55, 68; Sulloway 2008a, in 
litt.). Human settlement has resulted in changes to the habitat on 
Floreana, including clearing of native vegetation for agriculture and 
ranching, as well as the introduction of nonnative animals and plants 
(Grant et al. 2005, p. 501).
    The medium tree finch prefers to nest and forage in the tree 
Scalesia pedunculata (O'Connor et al. 2008b, in preparation). 
Currently, S. pedunculata only occurs in small patches in the highlands 
of Floreana because the highlands have been cleared for agriculture, 
destroyed by introduced mammals, and outcompeted by invasive plants 
(O'Connor et al. 2008b, in preparation). Although the Galapagos 
National Park covers 97 percent of the land on the Galapagos Islands, a 
disproportionate amount of the limited moist highlands falls in the 
remaining 3 percent (Stewart 2006, p. 105). As a result, a large amount 
of this area has been cleared or altered for farming, and the rest has 
been degraded or destroyed by the introduction of animals and plants 
(Stewart 2006, p. 105). Currently, only 12 km\2\ (4.5 mi\2\) to 17 
km\2\ (6.5 mi\2\) of habitat for the medium tree finch remains in the 
highlands of Floreana, and the amount of suitable habitat continues to 
decline due to the factors described below.

Agriculture and Ranching

    Birds, such as the medium tree finch, are currently facing problems 
in the highlands of inhabited islands like Floreana, due to the 
extensive destruction and degradation of habitat resulting from 
agriculture (BirdLife International 2008; Castro and Phillips 1996, pp. 
22-23; Fitter et al. 2000, p. 74). On Floreana, the highlands (or 
Scalesia zone) cover an area of approximately 21 km\2\ (8 mi\2\) 
(O'Connor et al. 2008b, in preparation). Within this highland forest, 
approximately 4 km2 (1.5 mi2) has been cleared for agriculture 
(O'Connor et al. 2008b, in preparation). Agriculture is concentrated at 
higher elevations because of the availability of richer soil and 
greater moisture (Schofield 1989, p. 233). The Scalesia zone is the 
richest zone in terms of soil fertility and productivity (Jackson 1985, 
p. 61), and, therefore, has been extensively cleared for agricultural 
and cattle ranching purposes (Grant 1986, p. 30; Harris 1982, p. 37; 
Jackson 1985, pp. 61, 233). When the forest is cleared for agriculture 
and ranching, or when cattle are allowed to roam freely within native 
vegetation, nesting and foraging sites of the medium tree finch are 
destroyed, which can have a negative effect on the species (Stotz et 
al. 1996, p. 121).

[[Page 74437]]

Introduced Species

    Introduced species are currently considered a major threat to the 
native species of the Galapagos Islands (Causton et al. 2006, p. 121; 
Fitter et al. 2000, p. 218). Since the early 1800s, humans have 
introduced animals and plants to the Galapagos Islands that have 
threatened the native vegetation (Schofield 1989, pp. 227, 233).

Animals

    When settlers arrived on the Galapagos Islands, they brought with 
them domestic animals, some of which escaped and started feral 
populations (Jackson 1985, p. 233). On Floreana, introduced animals 
include goats (Capra hircus), donkeys (Equs asinus), cattle, and pigs 
(Christensen and Kleindorfer 2008, in preparation; Jackson 1985, p. 
232). These animals impact the island by significantly altering the 
habitat (Grant et al. 2005, p. 501; Schofield 1989, pp. 229-233). This 
impact, as well as predation of endemic species by cats (Felis catus) 
and rats (Rattus rattus) (discussed under Factor C), has been linked 
with the extinction of at least four bird species on the island of 
Floreana: the large ground finch (Geospiza magnirostris), the sharp 
beaked ground finch (Geospiza difficilis), the Floreana mockingbird 
(Nesomimus trifasciatus) (Christensen and Kleindorfer 2008, in 
preparation; Grant et al. 2005, p. 501; Harris 1982, pp. 36-37; 
Sulloway 1982, pp. 68-69, 88-89), and, most recently, the warbler finch 
(Certhidea fusca) (Grant et al. 2005, p. 501).
    Introduced animals magnify the detrimental effects of clearing 
large areas of native vegetation on Floreana for agriculture and 
ranching (Grant 1986, p. 30), by further degrading and destroying the 
habitat (Grant et al. 2005, p. 501). The habitat of the medium tree 
finch continues to be altered by herbivore degradation caused by free-
ranging, domestic livestock (BirdLife International 2008; Jackson 1985, 
p. 110; Lawesson 1986, p. 12). Lawesson (1986) reported that the 
Scalesia forest on Floreana is under the most immediate threat from 
introduced animals (p. 13).
    Goats: Of all the introduced animals on the Galapagos Islands, 
goats are the most destructive animals (Fitter et al. 2000, p. 218; 
Schofield 1989, p. 227) and the most serious threat to Galapagos 
ecosystems (Harris 1982, p. 38; Smith 2005, p. 304). Goats were 
probably introduced to the Galapagos Islands in the 19th century by 
whalers, fisherman, and pirates, who were looking for an alternative 
source of meat (Charles Darwin Research Station 2006a; Fitter et al. 
2000, p. 218). They were also brought to the islands by settlers as 
livestock (Charles Darwin Research Station 2006a).
    Goats adapt to varying conditions extremely well, and they thrive 
at all elevations on the Galapagos Islands (Schofield 1989, p. 229), 
from the arid lowlands to the moist highlands (Fitter et al. 2000, p. 
218), where the medium tree finch occurs. They have a rapid 
reproductive rate, which has allowed their population to flourish at 
the expense of native animals and vegetation (Jackson 1985, pp. 232-
233).
    Goats destroy native vegetation by eating plants down to the ground 
(Smith 2005, p. 304), converting forests into barren grasslands and 
causing erosion (Charles Darwin Research Station 2006a). Their ability 
to eat almost anything has allowed goats to quickly eat their way 
across an island (Smith 2005, p. 304). A study of goats on Santiago 
Island in the Galapagos showed that at higher elevations, grazing by 
goats had eliminated young trees of Scalesia pedunculata, Zanthoxylum 
fagara, and Psidium galapageium, in addition to the forest understory 
(Schofield 1989, p. 229). On Floreana, Schofield (1989) reports that 
approximately 77 percent of the plant species, other than cacti, were 
either reduced in number or completely eliminated by goats (p. 229). 
Although feral goats have caused considerable damage to the vegetation 
in the highlands of Floreana, where the medium tree finch occurs 
(O'Connor 2008, in litt.), an eradication program begun in 2006 has 
most likely eliminated goats from the island of Floreana (Gardener 
2008, in litt.; O'Connor 2008, in litt.).
    Cattle: Cattle were introduced to Floreana in 1832 (Hoeck 1984, as 
cited in Schofield 1989, p. 231). Initially, cattle were kept at lower 
elevations, but with inadequate moisture available in the lower zones, 
they were allowed to move into the highlands (Kastdalen 1982, p. 9), 
where the medium tree finch occurs. Cattle trample and heavily graze 
upon native vegetation (Hamann 1981 and Van der Werff 1979, as cited in 
Schofield 1989, p. 231). When allowed to roam freely through highland 
forests, they essentially destroy the understory layer (Stotz et al. 
1996, p. 121). On Santa Cruz Island, cattle inhibited growth of 
Scalesia pedunculata (Kastdalen 1982, p. 8). Schofield (1989) reported 
that no organized effort had been made to eliminate cattle, but the 
Galapagos National Park Service does encourage ranchers to fence in 
herds on Floreana (p. 232). Although most cattle have been removed from 
within the boundaries of the Galapagos National Park (Gardener 2008, in 
litt.), cattle are still present in the highlands of Floreana and 
regularly roam freely within the habitat of the medium tree finch 
(O'Connor 2008, in litt.)
    Donkeys: In 1887, large numbers of donkeys (Equus asinus) were seen 
grazing on hillsides and at the summit on Floreana (Slevin 1959, as 
cited in Schofield 1989, p. 232). By 1932, donkeys had already tramped 
out regular paths through the vegetation on Floreana (Wittmer 1961, as 
cited in Schofield 1989, p. 232). On Santa Cruz, Kastdalen (1982) noted 
that they followed cattle into the humid highlands (p. 9). Studies have 
shown that donkeys on Floreana have depleted some populations of 
Scalesia spp. and Alternanthera nesiotes, another endemic plant 
(Eliasson 1982, p. 10). Today, donkeys still persist in the highlands 
of Floreana (Gardener 2008, in litt.; O'Connor 2008, in litt.), where 
the medium tree finch occurs.
    Pigs: Pigs (Sus scrofa) have lived on the Galapagos Islands for 
over 150 years (Schofield 1989, p. 232). In 1835, Darwin remarked upon 
the many wild pigs he observed in the forests on Floreana (Schofield 
1989, p. 232). Pigs live primarily at higher elevations, where abundant 
forage is available year-round (Schofield 1989, p. 232). Pigs destroy 
native vegetation (Jackson 1985, p. 233) directly by digging up and 
eating plants (Hoeck 1984, as cited in Schofield 1989, p. 232). 
Currently, pigs continue to be maintained in the agricultural areas of 
the highlands of Floreana (O'Connor 2008, in litt.), where the medium 
tree finch occurs.
    Eradication Programs: Since the Galapagos National Park and the 
Charles Darwin Foundation were established in 1959, efforts to control 
and eradicate introduced animals have been ongoing (Galapagos 
Conservancy n.d.(a)). In 1965, the Charles Darwin Research Station 
began the first eradication program to rid the Galapagos island of 
Santa Fe of goats (Fitter et al. 2000, p. 218). Ten years after the 
program began, the last goat was culled, and now the vegetation on the 
island has recovered and native species are beginning to thrive once 
again (Fitter et al. 2000, p. 218). Over the years, many of these 
control programs have been successful in eradicating introduced animals 
from some of the Galapagos Islands, including exterminating 25,000 
feral pigs on Santiago Island (Smith 2005, p. 305); removing goats from 
Espanola, Plaza Sur, Santa Fe, Marchena and Rabida Islands (Smith 2005, 
p. 305); and the very successful ``Project Isabela,''

[[Page 74438]]

which recently eliminated goats from Pinta Island, donkeys and goats 
from northern Isabela Island, and donkeys, goats, and pigs from 
Santiago Island (Galapagos Conservancy n.d.(b)).
    As a result of the success of Project Isabela, the Charles Darwin 
Foundation is planning several projects, in partnership with the 
Galapagos National Park Service, including eradication of goats and 
donkeys from Floreana (Charles Darwin Foundation n.d.(c)). In December 
2006, the Galapagos National Park started a project with the goal of 
restoring the ecology of Floreana (Galapagos Conservation Trust News 
2007). The first phase of ``Project Floreana'' is to eradicate some of 
the introduced animals, such as goats and donkeys, in order to stop the 
continuing degradation of the vegetation of the island and allow some 
of the native and endemic plant species to recover (Galapagos 
Conservation Trust News 2007).
    From the experience gained during Project Isabela, the program was 
able to eradicate 98 percent of the donkeys and goats on Floreana in 22 
days (Galapagos Conservation Trust News 2007). Currently, goats have 
been unofficially eradicated from Floreana; however, the elimination of 
donkeys is still in progress (Gardener 2008, in litt.). A follow-up 
census and control effort will be conducted next year to determine the 
results of this eradication program (Gardener 2008, in litt.). Due to 
the removal of these invasive species, it is expected that within the 
next few years the benefits to the ecosystem on Floreana will be seen 
(Galapagos Conservation Trust News 2007). This is expected to result in 
an increase in native flora and fauna, and the repopulation by native 
flora and fauna of areas previously destroyed on Floreana by herbivore 
degradation (Galapagos Conservation Trust News 2007). However, at this 
time, we believe that introduced species still pose a threat to the 
medium tree finch and its habitat.

Plants

    Introduced plants outcompete native vegetation for sunlight, water, 
and nutrients (Smith 2005, p. 304). Since agriculture is concentrated 
at higher elevations because of the rich soil and moisture available in 
these areas, introduced plants are more frequently found in the humid 
highland forests and often escape from cultivated areas into native 
vegetation (Schofield 1989, p. 233). Schofield (1989) found that 
accidental escape of introduced plant species, as well as the 
purposeful introduction of these species, had altered the highland 
habitat where tree finches occur (pp. 233-235).
    Christensen and Kleindorfer (2008, in preparation) found that the 
medium tree finch frequently forages on introduced fruit species. They 
report that this observation may suggest that the species is able to 
adapt to and potentially benefit from this change in their environment 
(Christensen and Kleindorfer 2008, in preparation). However, they did 
not observe any species of tree finch, including the medium tree finch, 
nesting in an introduced plant species (Christensen and Kleindorfer 
2008, in preparation). A further study by O'Connor et al. (2008b, in 
preparation) found that the majority (99 percent) of nests built by 
medium tree finches were constructed in native species, Scalesia 
pedunculata (83 percent), Zanthoxylum fagara (14 percent), and Croton 
scouleri (2 percent), with 1 percent of the nests built in an 
introduced species, guava (Psidium guajava).
    On Floreana, small populations of Scalesia forest still exist in 
the highlands, but these areas are under pressure and competition from 
the aggressive Psidium guajava and Lantana camara (Lawesson 1986, p. 
13).
    Guava: The cultivated guava (Psidium guajava) with its edible 
fruits is the most widespread introduced plant species on the Galapagos 
Islands (Schofield 1989, p. 233). Guava has been characterized as out 
of control and invading vast areas of native vegetation in the humid 
highlands on Floreana (Eckhardt 1972, p. 585; Eliasson 1982, p. 11; 
Tuoc 1983, p. 25). It is an aggressive, introduced plant that covers 
8,000 ha (19,768 ac) on Floreana (Parque Nacional Gal[aacute]pagos 
n.d.(a)).
    The dispersal of guava is aided by introduced cattle, which eat the 
fruits, and then wander from the farm into the National Park and 
excrete the seeds in their dung (De Vries and Black 1983, p. 19; Tuoc 
1983, p. 25). In addition, as cattle graze, they trample other 
vegetation, providing the open spaces and abundant light needed for the 
germination of guava seeds (Van der Werff 1979, as cited in Schofield 
1989, p. 233). Once guava becomes established in an open habitat, they 
grow quickly and shade seedlings of native species like Scalesia 
pedunculata, thus preventing their growth (Parque Nacional 
Gal[aacute]pagos n.d.(a); Perry 1974, p. 12).
    One obvious step to take in order to minimize the further spread of 
guava is to fence cattle (De Vries and Black, p. 19; Tuoc 1983, p. 25). 
Although some residents have already done this, herds of free-ranging 
cattle are unable to be restricted in this manner (Schofield 1989, pp. 
233-234). In 1971, a campaign was started to cut down guava trees on 
Santa Cruz Island (Schofield 1989, p. 234). One report indicated that 
more than 95,000 guava trees were eliminated between 1980 and 1981 
(Tuoc 1983, p. 25). Schofield (1989) believes that this program should 
be expanded to other islands with large populations of guava (p. 234). 
Currently, we have no information to indicate that a program to 
eliminate guava has occurred on Floreana.
    Other Plant Species: Floreana is also impacted by other introduced 
plant species. Lantana camara was introduced as an ornamental on 
Floreana in 1832, and now covers 3,000 ha (7,413 ac) (Parque Nacional 
Gal[aacute]pagos n.d.(a)). It is a quick spreading, tropical shrub that 
displaces native vegetation, and is now found on Floreana from the arid 
region up to the Scalesia forest (Hamann 1984, as cited in Schofield 
1989, p. 234). Citrus trees (Citrus spp.) have been reported as 
``common'' (Eliasson 1982, p. 11) and have invaded the native 
vegetation at higher elevations on Floreana (Eliasson 1982, p. 11; 
Porter 1973, p. 276). Cattle and pigs aid in the further spread of 
citrus trees (Citrus spp.) by feeding on the fruits and dispersing 
seeds in new locations (Wittmer 1961, as cited in Schofield 1989, p. 
234).

Summary of Factor A

    The medium tree finch is found primarily in the moist highland 
forests (i.e., the Scalesia zone) on the island of Floreana. Since the 
island was first settled in 1832, the habitat of the medium tree finch 
has been cleared for agriculture and ranching, and further degraded by 
introduced animals and plants. Herbivores, such as donkeys, cattle, and 
pigs, continue to destroy the species' habitat by trampling and grazing 
heavily on native vegetation, including Scalesia pedunculata, the tree 
primarily used by the medium tree finch for nesting and foraging. In 
addition, cattle and pigs help to spread introduced plants, such as 
guava and citrus trees, by feeding on the fruits and depositing the 
seeds into native vegetation. These introduced plants outcompete native 
species, such as Scalesia pedunculata, reducing the availability of 
nest sites for the medium tree finch. Although an eradication program 
was started in December 2006 to eliminate goats and donkeys from 
Floreana, we are not aware of any current programs to remove cattle and 
pigs from the island. As a result, these introduced species will 
continue to destroy and degrade the habitat of the

[[Page 74439]]

medium tree finch, which has already been reduced to an area of only 12 
km2 (4.5 mi2) to 17 km2 (6.5 
mi2). Therefore, we find that habitat destruction of the 
moist highland forests of Floreana, as a result of agriculture and 
introduced species, is a threat to the continued existence of the 
medium tree finch.

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

    We are not aware of any scientific or commercial information that 
indicates overutilization of the medium tree finch for commercial, 
recreational, scientific, or educational purposes poses a threat to 
this species. As a result, we are not considering overutilization to be 
a contributing factor to the continued existence of the medium tree 
finch.

C. Disease or Predation

Disease
    The recent discovery of an introduced parasitic fly (Philornis 
downsi) on Floreana Island (Kleindorfer, pers. comm., as cited in Grant 
et al. 2005, p. 502; Wiedenfeld et al. 2007, p. 17) has raised concerns 
about the impact this parasite might be having on the medium tree finch 
(Dudaniec et al. 2008; Fessl et al. 2006b, p. 59). In March 1997, 
Fessl, Couri, and Tebbich observed the presence of Philornis downsi in 
the nests of Darwin's finches on the Galapagos Islands for the first 
time (Fessl and Tebbich 2002, p. 445).
    Philornis downsi was sampled by the entomologists S.B. and J. Peck, 
and B.J. Sinclair, in 1989, although the fly was not formally 
identified until the collections were examined in detail in 1998 (Fessl 
and Tebbich 2002, p. 445; Fessl et al. 2001, p. 318). However, it now 
appears that P. downsi was present on the Galapagos Islands at least 40 
years ago, as it was recently identified from collections made on Santa 
Cruz Island in 1964 (Causton et al. 2006, pp. 134, 143). We are not 
aware of any information indicating when P. downsi may have been 
introduced to the island of Floreana.
    Philornis downsi is a Muscidae (fly) from a genus of obligate bird 
parasites (Couri 1985, as cited in Fessl and Tebbich 2002, p. 445; 
Fessl et al. 2001, p. 317), depending entirely on a host for its 
survival. The adult fly is non-parasitic, and feeds on fruits, flowers, 
and decaying material (Fessl et al. 2001, p. 317; Fessl et al. 2006b, 
p. 56). Larvae of P. downsi belong to the group of external 
haematophages (bloodsuckers); first, second, and third instar 
(developmental stage) larvae are blood feeders, believed to suck blood 
from nestlings during the night and then retreat to the bottom of the 
nest during the day (Dodge and Aitken 1968 and Skidmore 1985, as cited 
in Fessl et al. 2006b, p. 56). Adult flies lay eggs inside the nasal 
cavities of newly hatched nestlings (usually 1 to 3 days old), which 
hatch into first instar larvae (Muth 2007, as cited in Dudaniec et al. 
2008; Fessl et al. 2006a, p. 744). As the larvae reach their second 
instar stage, they exit the nasal cavities of nestlings and begin to 
live as nest-dwelling haematophagous larvae (Fessl et al. 2006a, p. 
744). Second and third instar larvae of P. downsi seem to be 
exclusively external (Fessl et al. 2006b, p. 59), feeding on the blood 
and tissues of nestlings (Dudaniec and Kleindorfer 2006, pp. 15-16). 
The majority of larvae reach their third instar stage at the time of 
host fledging (Dudaniec et al. 2008). At this stage, the larvae of P. 
downsi detach from the nestling and form their pupae at the bottom of 
the nesting material, remaining for approximately 2 weeks before 
emerging as adult flies (Dudaniec and Kleindorfer 2006, p. 16; Fessl et 
al. 2006b, p. 56).
    Philornis downsi occurs in finch nests on Floreana (Wiedenfeld et 
al. 2007, p. 17), and has been shown to significantly lower fledgling 
success of the finches (Fessl and Tebbich 2002, pp. 448-450). A number 
of studies have associated Philornis parasitism with mortality (Fessl 
and Tebbich 2002, p. 448), reduced nestling growth and development 
(Fessl et al. 2006b, p. 58), and a reduction in hemoglobin level 
(Dudaniec et al. 2006, p. 88).
    A study by Fessl and Tebbich (2002) on Santa Cruz Island found that 
97 percent of finch nests were infected with the Philornis downsi 
parasite, both in the lower arid zone and the higher Scalesia zone of 
the island (p. 449). Parasitism by P. downsi caused complete brood loss 
in approximately 19 percent of the infected finch nests and partial 
brood loss (defined as the successful fledging of one or two nestlings) 
in an additional 8 percent of the finch nests studied (Fessl and 
Tebbich 2002, p. 448). They also found that in parasitized nests, the 
percentage of successful fledglings differed significantly depending 
upon brood size; nests with only one nestling always failed, nests with 
two nestlings successfully fledged nestlings 50 percent of the time, 
and nests with three or four nestlings successfully fledged nestlings 
75-85 percent of the time (Fessl and Tebbich 2002, p. 448). The high 
nestling mortality in small broods may be the result of the high 
parasite-to-nestling ratio, as compared to larger broods (Fessl and 
Tebbich 2002, p. 449). Since P. downsi infects nests regardless of the 
number of nestlings (Fessl and Tebbich 2002, p. 450), large broods may 
be able to spread the larval load among more nestlings, thereby 
reducing the number of larvae affecting each individual nestling.
    In an experimental study conducted on Santa Cruz Island, Fessl et 
al. (2006b) found that high mortality of nestlings was directly 
attributable to parasitism by Philornis downsi, as evidenced by a near 
threefold increase in fledgling success in a parasite-reduced group 
(86.6 percent) versus a parasite-infested control group (33.9 percent) 
(pp. 58-59). They also found that within 4 days, mass gain was 
significantly higher (an almost two-fold positive difference) in the 
parasite-reduced group than in the parasite-infested control group 
(Fessl et al. 2006b, p. 58). In studies of other avian species, 
fledgling body mass has been found to be a key factor for juvenile 
survival (Magrath 1991, pp. 343-344; Tinbergen and Boerlijist 1990, pp. 
1123-1124). As a result, Fessl et al. (2006b) concluded that the 
results of their study showed that given the significant difference in 
body mass between the two groups, parasitized nests will likely provide 
less recruitment into the breeding population (p. 59). Further, because 
species with small broods have been found to suffer higher parasite 
loads and higher nestling mortality (Fessl and Tebbich 2002, pp. 445, 
449-450), infestation of P. downsi on species with naturally low clutch 
sizes, such as the medium tree finch, is of particular concern (Fessl 
et al. 2006b, p. 59).
    Dudaniec et al. (2006) found a significant negative correlation 
between Philornis downsi parasite intensity and hemoglobin 
concentrations, and a positive correlation between parasite intensity 
and immature red blood cell counts, in small ground finches studied on 
Santa Cruz and Floreana Islands (pp. 88, 90, 92). Small ground finch 
nestlings with higher P. downsi intensities suffered from lower 
hemoglobin concentrations and reduced fledging success (Dudaniec et al. 
2006, p. 92). Furthermore, nestlings with lower parasite intensity had 
higher hemoglobin levels and increased fledging success (Dudaniec et 
al. 2006, p. 93). Dudaniec et al. (2006) also found a negative 
correlation between the number of immature red blood cells and 
hemoglobin levels in nestlings (p. 92).
    The fitness impacts to nestlings of lower hemoglobin levels are 
likely to be significant (Dudaniec et al. 2006, p. 93). The results of 
a study by O'Brien et al. (2001) showed that low hemoglobin levels in 
nestlings reduce the transport

[[Page 74440]]

of oxygen to tissues (p. 75). Thus, fledglings that are anemic 
(hemoglobin deficient) from parasite feeding may have a reduced ability 
to sustain flight and, consequently, a reduced ability to escape 
predators and find food (O'Brien et al. 2001, p. 75). The high 
hemoglobin levels found by Dudaniec et al. (2006) in mature birds, 
combined with their observation that adult finches were never found to 
be actively parasitized, suggest that adult birds are not 
physiologically affected by Philornis downsi (p. 92).
    Fessl et al. (2006a) reported extremely high levels of blood loss 
in nestlings (18 to 55 percent) caused by Philornis downsi larvae (p. 
745). Daily blood loss over 10 percent is likely to have negative 
impacts on nestlings, including health problems and developmental 
deficiencies, while blood loss over 25 percent would become lethal 
(Kaneko, pers. comm., as cited in Gold and Dahlsten 1983, p. 569).
    In 2006, nesting success in the medium tree finch was examined for 
the first time (Fessl et al. 2006a, p. 746). The study by O'Connor et 
al. (2008a, in preparation) on tree finches in the highlands of 
Floreana showed that the medium tree finch had the highest Philornis 
downsi parasite intensity (an average of 52 parasites per nest), 
compared to small and large tree finches. Of 63 medium tree finch 
nests, only 16 nests had nestlings that survived to 6 days post-
hatching, and only 4 nests produced fledglings (O'Connor et al. 2008a, 
in preparation). Most nests failed to produce fledglings; 68.8 percent 
(11 of 16) of medium tree finch nests suffered total brood loss, while 
18.8 percent (3 of 16) of nests had partial brood loss (O'Connor et al. 
2008a, in preparation). Philornis downsi larvae or pupae were found in 
100 percent (16 of 16) of medium tree finch nests, and all nestlings 
had P. downsi parasites (O'Connor et al. 2008a, in preparation). The 
majority (54 percent) of nestling mortality in medium tree finches was 
due to parasitism by P. downsi (O'Connor et al. 2008a, in preparation). 
All nestlings found dead in nests had large open wounds on their bodies 
and significant loss of blood or body fluids, all of which are signs of 
P. downsi parasitism (O'Connor et al. 2008a, in preparation).
    O'Connor et al. (2008a, in preparation) discuss the reasons why the 
Philornis downsi parasite intensity is high in the medium tree finch. 
One possibility they explain is that the medium tree finch's preferred 
breeding habitat is next to an agricultural area, where the close 
proximity of the agriculture fields (with citrus trees and other 
fruits) act as a feeding location for the adult flies (O'Connor et al. 
2008a, in preparation). In addition, moist highlands favor consistent 
breeding of medium tree finches, thus providing flies with a dependable 
supply of nestlings for P. downsi larvae to feed upon (O'Connor et al. 
2008a, in preparation). Currently, the medium tree finch has the 
highest P. downsi parasite intensity of any finch species on Floreana, 
and the second highest of any finch species studied on the Galapagos 
Islands (O'Connor et al. 2008a, in preparation).
    A study by Wiedenfeld et al. (2007) found that there was a 
significant increase in the number of Philornis downsi parasites 
(larvae, pupae, or puparia) per nest at higher altitudes (i.e., in the 
humid highlands) (pp. 17-18). According to their study, the 
distribution of P. downsi seems to be related to the amount of humidity 
and moisture available on the islands (Wiedenfeld et al. 2007, p. 18). 
Although it appears that the fly does more poorly in dry conditions 
(either in the lowland, arid zone of islands, or during drought), birds 
also do more poorly in these situations (Wiedenfeld et al. 2007, p. 
18). In addition, during years of abundant rainfall when birds breed 
more successfully, the flies are also likely to be more plentiful, and, 
therefore, can cause higher mortality (Wiedenfeld et al. 2007, p. 18).
    It is believed that finches do not suffer from any type of endemic, 
haematophagous ectoparasite (a bloodsucking parasite that lives on the 
outside of its host, and not within the host's body) (Fessl et al. 
2006b, p. 56). Therefore, they have not developed an adaptive response 
to this kind of introduced pathogen (Altizer et al. 2003, as cited in 
Dudaniec and Kleindorfer 2006, p. 19). Because the medium tree finch is 
newly colonized by Philornis downsi, it may experience significant 
initial mortality since the host has not yet developed a strong 
behavioral or immunological defense mechanism against the parasite 
(Dudaniec and Kleindorfer 2006, pp. 18-19).
    As many of these studies show, finches have a slim chance of 
reproducing without avoiding effects of Philornis downsi mortality 
(Dudaniec and Kleindorfer 2006, p. 18; Wiedenfeld et al. 2007, p. 18). 
Causton et al. (2006) developed a system to evaluate the invasiveness 
of insect species introduced to the Galapagos Islands based on trophic 
functional role, distribution in the Galapagos, and their history of 
invasiveness elsewhere (p. 121). Philornis downsi was given the highest 
invasiveness ranking affecting fauna endemic to the Galapagos Islands, 
because P. downsi seriously impacts species of high conservation value 
in the Galapagos (Causton et al. 2006, pp. 123, 134). Grant et al. 
(2005) reported that the decline and possible local extinction of one 
of Darwin's finches, the warbler finch (Certhidea fusca), on Floreana 
by 2004 may have been partially caused by P. downsi (p. 502; Fessl et 
al. 2006b, p. 59), although there is no conclusive evidence (Dudaniec 
and Kleindorfer 2006, p. 13).
    It is best to eliminate invasive species before they are able to 
adapt to the local environment in which they have colonized (Frankham 
2005, p. 385). However, for Philornis downsi, this introduced parasitic 
fly has become firmly established in the Galapagos Islands, prompting 
the need for a long-term eradication program in conjunction with 
continuous quarantine and monitoring practices (Dudaniec et al. 2008).
    Programs to eradicate Philornis downsi from the Galapagos Islands 
are difficult and costly (Fessl et al. 2006b, p. 59). In the 
experimental study by Fessl et al. (2006b), they found that a single 
insecticide treatment of 1 percent pyrethrin solution (done at a 
nestling age of 4 days) was sufficient to reduce the number of 
parasites per nest to almost zero (pp. 57-59). This treatment offers 
one short-term solution to locally protect single nests of species of 
high conservation concern (Fessl et al. 2006b, p. 59). However, this 
treatment is not practicable as a long-term solution for controlling 
the fly throughout the Galapagos Islands because it would be extremely 
labor intensive and would require the nests of all host species to be 
treated on every island in the Galapagos where P. downsi is found (at 
least 11 islands; Wiedenfeld et al. 2007, p. 16).
    The Charles Darwin Foundation (CDF) has begun an effort to develop 
biological control approaches for Philornis downsi (Charles Darwin 
Foundation n.d.(c)). In 2008, CDF received $58,000 for Phase I of the 
CDF Priority Project: ``Control of the parasitic fly Philornis downsi'' 
(Charles Darwin Foundation n.d.(a)). This project will study the 
biology and life history of P. downsi, aiding in the development of 
effective, long-term control methods that will not harm other species 
(Charles Darwin Foundation 2007). CDF reports that control methods are 
urgently needed to eliminate the threat of extinction among bird 
species, such as the medium tree finch, affected by this parasite 
(Charles Darwin Foundation 2007).

[[Page 74441]]

Predation
    Floreana has a suite of introduced predators including black rats 
(Rattus rattus) and cats (Felis catus) (Kleindorfer et al. 2008, in 
preparation). These predators feed on eggs, nestlings, and even adult 
birds (Castro and Phillips 1996, p. 22), and have depleted native 
populations (Grant et al. 2005, p. 501; Jackson 1985, p. 232).
    Rats: Black rats are one of the worst introduced species to the 
Galapagos Islands, destroying bird nests and eggs, and consuming 
hatchlings (Charles Darwin Foundation n.d.(b); Charles Darwin Research 
Station 2006b). Rats arrived on the Galapagos Islands on ships 
beginning in the late 1600s, and currently are found on all inhabited 
islands, including Floreana (Charles Darwin Research Station 2006b). 
Rats are currently present in the highlands of Floreana, and can be 
seen running up and down trees, or along the forest floor in the 
habitat of the medium tree finch (O'Connor 2008, in litt.). Because 
rats can easily climb, they have been implicated in the population 
declines of tree-nesting birds, such as the mangrove finch 
(Camarhynchus heliobates) (Charles Darwin Research Station 2006b).
    The CDF's long-term plan is to successfully eradicate introduced 
rats on all islands, a necessary measure in order to restore the 
Galapagos Islands and its endemic species (Charles Darwin Research 
Station 2006b). Currently, a control program is ongoing in the 
highlands of Floreana to control rats in the nesting area of the 
Galapagos petrel (Pterodroma phaeopygia) (Gardener 2008, in litt.). The 
project is being conducted at Cerro Pajas (Cruz and Cruz 1996, pp. 25-
30), the site of the largest patch of prime Scalesia habitat (9 km\2\ 
(3.5 mi\2\)) (O'Connor 2008, in litt.), where the medium tree finch 
occurs. Although an eradication program has begun, it has not yet been 
completed, and therefore, rats remain a threat to the medium tree 
finch.
    A study of tree finches in the highlands of Floreana by O'Connor et 
al. (2008a, in preparation) found that one-third of medium tree finch 
nests experienced nestling predation (in both years, 2006 and 2008), 
and egg depredation was observed in 22 percent of the nests (but only 
in 2008). Although nest predation was not observed directly, the 
identity of the predators could be inferred from the condition of the 
nest (O'Connor 2008, in litt.). It is likely that rats were 
predominantly responsible for the predation (O'Connor 2008, in litt.). 
Because agricultural areas are close to the breeding sites of the 
medium tree finch, they provide support for the continued persistence 
and movement of introduced predators, mainly rodents (O'Connor et al. 
2008a, in preparation).
    Cats: Cats are highly predatory animals, targeting birds and other 
native species (Charles Darwin Foundation n.d.(b); Charles Darwin 
Research Station 2006c; Smith 2005, p. 304). Cats were introduced to 
the Galapagos Islands by ships and as domestic pets of settlers 
(Charles Darwin Research Station 2006c). Today, cats are currently 
found in the agricultural areas of the highlands of Floreana (Gardener 
2008, in litt.; O'Connor 2008, in litt.), where the medium tree finch 
occurs.
    Both feral and domestic cats prey upon and impact the survival of 
Darwin's finches, and are a threat to endemic species on Floreana 
(Charles Darwin Research Station 2006c). In the 19th century, cats may 
have caused significant declines in the populations of large ground 
finches, sharp-beaked ground finches, and mockingbirds, pushing them 
toward extinction on Floreana (Grant et al. 2005, p. 501).
    The Galapagos National Park Service and the CDF are working to 
control and eradicate domestic and feral cats on all of the islands 
(Charles Darwin Research Station 2006c). This plan includes working 
with communities to gain acceptance of and compliance with the 
sterilization or removal of domestic cats, and the development of an 
eradication program to eliminate feral cats from natural areas on all 
populated islands, such as Floreana (Charles Darwin Research Station 
2006c).

Summary of Factor C

    Philornis downsi, an introduced parasitic fly, poses a significant 
threat to the survival of the medium tree finch. The larvae feed on 
finch nestlings causing mortality, reduced nestling growth, lower 
fledgling success, and a reduction in hemoglobin levels, which all 
combine to severely affect the recruitment dynamics of the species. The 
medium tree finch has the highest P. downsi parasite intensity of all 
the finch species found on Floreana, and the second highest of any 
finch species studied on the Galapagos Islands. Although a project 
examining the biology of P. downsi and how to control it was begun in 
2008, a long-term control method for the parasitic fly has not yet been 
developed. As a result, the medium tree finch and its reproductive 
success will continue to be negatively impacted by P. downsi. 
Therefore, we find that parasitism by Philornis downsi is a significant 
threat to the continued existence of the medium tree finch.
    Introduced predators on Floreana, such as black rats and cats, feed 
on eggs and nestlings of birds, causing dramatic reductions in native 
populations. One study found that 33 percent of medium tree finch nests 
experienced nestling predation, while egg depredation was observed in 
22 percent of the nests. Although nest predation was not observed 
directly, rats are most likely responsible for much of the predation. 
In an effort to help restore endemic species on the Galapagos Islands, 
one goal of CDF was to develop programs to eradicate introduced rats 
and cats on all islands. Even though an effort to eliminate rats from 
the Galapagos petrel nesting area in the highlands of Floreana has 
begun, it has not yet been completed. Furthermore, we do not have any 
information to indicate that an eradication program for cats has begun 
on the island of Floreana. Therefore, we find that predation is a 
threat to the continued existence of the medium tree finch.

D. Inadequacy of Existing Regulatory Mechanisms

    The medium tree finch is identified as a ``critically endangered'' 
species under Ecuadorian law and Decree No. 3,516--Unified Text of the 
Secondary Legislation of the Ministry of Environment of 2002 (ECOLEX 
2003b). Decree No. 3,516 of 2002 summarizes the law governing 
environmental policy in Ecuador and provides that the country's 
biodiversity be protected and used primarily in a sustainable manner 
(ECOLEX 2003b). Appendix 1 of Decree No. 3,516 lists the Ecuadorian 
fauna and flora that are considered threatened or in danger of 
extinction. Species are categorized as critically endangered (En 
peligro cr[iacute]tico), endangered (En peligro), or vulnerable 
(Vulnerable).
    Resolution No. 105--Regulatory Control of Hunting Seasons and 
Wildlife Species in the Country and Agreement No. 143--Standards for 
the Control of Hunting Seasons and Licenses for Hunting of Wildlife, 
regulate and prohibit commercial and sport hunting of all wild bird 
species, except those specifically identified by the Ministry of the 
Environment or otherwise permitted (ECOLEX 2000; ECOLEX 2003a). The 
Ministry of the Environment does not permit commercial or sport hunting 
of the medium tree finch because of its status as a ``critically 
endangered'' species (ECOLEX 2003b). However, we do not consider 
hunting (Factor B) to be a threat to the medium tree finch, so this law 
does not address any of the threats to the species.
    The first legislation to specifically protect the Galapagos Islands 
and its

[[Page 74442]]

wildlife and plants was enacted in 1934 and further supplemented in 
1936, but effective legislation was not passed until 1959, when the 
Ecuadorian government passed new legislation declaring the islands a 
National Park (Fitter et al. 2000, p. 216; Jackson 1985, pp. 7, 230; 
Stewart 2006, p. 164). Ecuador designated 97 percent of the Galapagos 
land area as the National Park, leaving the remaining 3 percent 
distributed between the inhabited areas on Santa Cruz, San 
Crist[oacute]bal, Isabela, and Floreana Islands (Jackson 1985, p. 230; 
Schofield 1989, p. 236). A disproportionate amount of the limited moist 
highlands falls in the remaining 3 percent (Stewart 2006, p. 105). The 
land is divided into various zones signifying the level of human use 
(Parque Nacional Gal[aacute]pagos n.d.(b)). Although Floreana Island 
includes a large ``conservation and restoration'' zone, it does include 
a significant ``farming'' zone (Parque Nacional Gal[aacute]pagos 
n.d.(b)), where agricultural and grazing activities continue to impact 
the habitat.
    In March 1998, the National Congress and the Ecuadorian President 
enacted the Law of the Special Regimen for the Conservation and 
Sustainable Development of the Province of the Galapogos, which has 
given the islands some legislative support to establish regulations 
related to the transport of introduced species and implement a 
quarantine and inspection system (Causton et al. 2000, p. 10; Instituto 
Nacional Gal[aacute]pagos n.d.; Smith 2005, p. 304).
    As a result, in 1999, the Inspection and Quarantine System for 
Galapagos (SICGAL) was implemented (Causton et al. 2006, p. 121), with 
the aim of preventing introduced species from reaching the islands 
(Causton et al. 2000, p. 10; Charles Darwin Foundation n.d.(d)). 
Inspectors are stationed at points of entry and exit on the Galapagos 
Islands and Continental Ecuador, where they check freight and luggage 
for permitted and prohibited items (Charles Darwin Foundation n.d.(d)). 
The goal is to rapidly contain and eliminate newly arrived species 
(detected by SICGAL and early warning monitoring programs) that are 
considered threats for the Galapagos Islands (Causton et al. 2006, p. 
121). However, a scarcity of information on alien insect species 
currently on the Galapagos Islands prevents officials from knowing 
whether or not a newly detected insect is in fact a recent introduction 
(Causton et al. 2006, p. 121). Without the necessary information to 
make this determination, they cannot afford to spend the time and 
resources on a rapid response when the ``new introduction'' is actually 
a species that already occurs elsewhere on the Galapagos Islands 
(Causton et al. 2006, p. 121).
    The April 2007 World Heritage Centre-IUCN monitoring mission report 
assessed the state of conservation on the Galapagos Islands based on 
information gathered during their monitoring mission and multiple 
meetings, and found continuing problems (UNESCO World Heritage Centre 
2007). The report found deficiencies that preclude the full application 
and enforcement of the Special Law for Galapagos (UNESCO World Heritage 
Centre 2007). Also, although the risk from invasive species is rapidly 
increasing, the report found that the Agricultural Health Service of 
Ecuador (SESA) and SICGAL do not have adequate staff and capacity to 
deal with the nature and scale of the problem (UNESCO World Heritage 
Centre 2007). SICGAL estimates that 779 invertebrates entered the 
Galapagos Islands via aircraft in 2006 (UNESCO World Heritage Centre 
2007). In addition, the report found that the staff of the Galapagos 
National Park lack the capacity and facilities for effective law 
enforcement (UNESCO World Heritage Centre 2007).
    Previous UNESCO-IUCN Galapagos mission reports (in 2005 and 2006) 
to the World Heritage Committee have consistently outlined major 
threats to the long-term conservation of the Galapagos Islands, 
including the introduction of nonnative plant and animal species 
(UNESCO World Heritage Centre News 2007b). UNESCO World Heritage Centre 
reports that, despite an excellent legal framework, national government 
institutions encoun