Federal Register: June 18, 2008 (Volume 73, Number 118)
DOCID: fr18jn08-23 FR Doc E8-13840
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
CFR Citation: 50 CFR Part 17
FWS ID: [FWS-R7-ES-2008-0004; 1111 FY07 MO-B2]
NOTICE: PROPOSED RULES
ACTION: Endangered and Threatened Wildlife and Plants:
DOCUMENT ACTION: Notice of 90-day petition finding.
Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Long-Tailed Duck (Clangula hyemalis) as Endangered
DATES: The finding announced in this document was made on June 18, 2008. You may submit new information concerning this species for our consideration at any time.
We, the U.S. Fish and Wildlife Service (Service), announce a
90day finding on a petition to list the longtailed duck (Clangula
hyemalis) as endangered under the Endangered Species Act of 1973, as
amended (Act). We find that the petition does not present substantial
scientific or commercial information indicating that listing the species may be warranted.
Therefore, we will not initiate a further status review in response to this petition. We ask the public to submit to us any new information that becomes available concerning the status of the longtailed duck or threats to it or its habitat at any time. This information will help us monitor and encourage the conservation of the species.
Long-tailed Duck (Clangula hyemalis),
Section 4(b)(3)(A) of the Act (16 U.S.C. 1531 et seq.) requires that we make a finding on whether a petition to list, delist, or reclassify a species presents substantial scientific or commercial information to indicate that the petitioned action may be warranted. We are to base this finding on information provided in the petition, supporting information submitted with the petition, and information otherwise available in our files at the time we make the determination. To the maximum extent practicable, we are to make this finding within 90 days of our receipt of the petition, and publish our notice of this finding promptly in the Federal Register.
Our standard for substantial information within the Code of Federal Regulations (CFR) with regard to a 90day petition finding is ``that amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted'' (50 CFR 424.14(b)). If we find that substantial information was presented, we are required to promptly commence a review of the status of the species.
In making this finding, we based our decision on information provided by the petitioner and otherwise available in our files at the time of the petition review, and we evaluated this information in accordance with 50 CFR 424.14(b). Our process for making a 90day finding under section 4(b)(3)(A) of the Act and 50 CFR 424.14(b) of our regulations is limited to a determination of whether the information in the petition meets the ``substantial information'' threshold. Petition
On February 10, 2000, we received an undated petition from Nancy Hillstrand, Homer, Alaska, to list the longtailed duck as endangered and to designate critical habitat in southcentral and southeastern Alaska, including Kodiak and the Aleutians, the YukonDelta National Wildlife Refuge, and the National Petroleum Reserve. The petition itemizes threats to the species based on personal observations. The petition references, but does not provide supporting data on, multiple threats to the longtailed duck and other species of the Tribe Mergini. As the petition does not specify the particular population to be listed as endangered, the Service assumed the petitioned action was to list the species as endangered throughout its entire range. On March 10, 2000, the Service informed the petitioner that funds available for listing activities were fully allocated to higherpriority actions associated with statutory requirements and active litigation, and that we would address the petition as funding became available. We also concluded in our March 10, 2000, letter that emergency listing of the longtailed duck was not indicated. Responding to the petition was further delayed due to the high priority of responding to court orders and settlement agreements regarding other species, until funding recently became available to respond to the petition. This finding fulfills the Service's obligation under 16 U.S.C. 1533(b)(3)(A) and its implementing regulations at 50 CFR 424.14(b).
Biology and Distribution
The longtailed duck (Clangula hyemalis) (Order Anseriformes, Family Anatidae) is a small to mediumsized sea duck, with a long tail, steep forehead, flattened crown, small stout bill, and strongly contrasting plumages of white, black, and brown. It is most similar to the harlequin duck (Histrionicus histrionicus) and Steller's eider (Polysticta stelleri). Adults weigh roughly 750 to 1,000 grams (1.7 to 2.2 pounds) and measure roughly 38 to 53 centimeters (15 to 21 inches) in length. Average male body mass and size is greater than that of the female.
The longtailed duck is Holarctic in distribution, breeding in tundra and taiga regions around the globe as far north as 80 degrees north latitude. With a worldwide population of more than seven million birds, this species may be the most abundant Arctic sea duck. The following information regarding the description and natural history of the longtailed duck has been condensed from Robertson and Savard (2002) and Wilbor (1999). Specific references are cited for data of particular relevance to this finding.
In North America, the longtailed duck breeds from the northern coast of Alaska east across Canada to Ellesmere and Baffin Islands and northern Labrador south to southern and central Alaska, northwestern British Columbia, eastern and southcentral Ontario, and Hudson and James Bays (Robertson and Savard 2002, p. 3). This species winters on both coasts of North America and on the Great Lakes. In western North America, it winters throughout the Aleutian Islands and Kodiak Island and along coastal southern Alaska, the entire British Columbia coast, the Puget Sound, and coastal Washington State south to northern Oregon (Robertson and Savard 2002, p. 3). It is rare along the Oregon and California coasts and present throughout all western provinces and States east to Colorado and Utah and south to Gulf of California, Mexico. On the east coast of North America, it winters from southern Labrador, Newfoundland, St. Lawrence estuary, Gulf of St. Lawrence, Prince Edward Island, Nova Scotia, Gulf of Maine, and along the New England coast and Chesapeake Bay south to Cape Hatteras, North Carolina. It is common south to the north shore of the Gulf of Mexico and Atlantic Coast to Florida and rare as far south as Bermuda. Inland, it winters on all five Great Lakes. Small numbers are scattered throughout many water bodies in eastern North America. It remains in northern areas as long as open water is available.
In the Palearctic, the breeding range of the longtailed duck is
circumpolar, including all of coastal Greenland (except the far north),
Iceland, northern Scandinavia, the north coast of continental arctic
Russia to the Chukotska Peninsula, and most offshore islands. It
winters in southwest Greenland and throughout most of Iceland. Large numbers winter in the
Baltic Sea and Finland, and in the North Sea and coastal Norway. In the Pacific, the species winters along eastern and southern Kamchatka Peninsula, along Commander Island, Bering Strait, and northern Anadyr Gulf.
Longtailed ducks breed over a vast range and at low densities, making comprehensive surveys of their abundance difficult. They are even more difficult to monitor in winter due to their offshore distribution. Although incomplete survey coverage reduces reliability of population size and trend estimates, current population estimates suggest they are the most abundant Arctic sea duck. The North American population may number up to two million birds (USFWS 2001, p. 45). Approximately 200,000 birds breed in Alaska; the remainder breeds in Canada (USFWS 2003, p. 50). Miyabayashi and Mundkur (1999, p. 118) estimate 500,000 to 1,000,000 birds breed and winter in eastern Asia. Nearly 150,000 birds breed in Iceland and Greenland (Wetlands International 2002, p. 97), and an estimated 4,600,000 breed in western Siberia and northern Europe (Scott and Rose 1996, p. 208). The size of the prebreeding population (birds less than 3 years old) is unknown.
Although the Icelandic breeding population experienced a marked decline in the early 20th century, the breeding populations in Iceland and Greenland are now thought to be stable (Wetlands International 2002, p. 97). Scott and Rose (1996, p. 208) indicated that post breeding numbers on the tundra of western and central Siberia and breeding populations in northern Europe were stable between 1972 and 1989. In contrast, several surveys suggest declining longtailed duck populations in some parts of Alaska and Canada. The North American Waterfowl Breeding Population Survey indicated an average annual decline of 5.3 percent from 1973 to 1997 (USFWS 2001, p. 45), and Conant and Groves (2005, p. 5) report a 29year downward trend for longtailed ducks in Alaska and the Yukon Territory. Larned, et al. (2005, p. 7) reported an insignificant decline in longtailed duck numbers on the Arctic Coastal Plain in Alaska, and Mallek, et al. (2006, p. 4) reported a significant downward 20year trend for the same area. However, existing breeding population surveys must be interpreted with caution. Both Conant and Groves (2005, p. 9) and Larned, et al. (2005, p. 7) suggest that survey timing relative to spring arrival (whether early or late) may account for the lower abundances detected in recent years. The North American Waterfowl Breeding Population Survey does not include major breeding grounds in Canada and Alaska, its transect lines are not located systematically throughout all habitat strata, and it is unlikely that birds are evenly distributed in the sampled area. Such incomplete survey coverage represents an obstacle to providing reliable population and trend estimates for species like the longtailed duck that occur over vast regions at low densities (USFWS 2001, p. 45). In contrast to suggested population declines in northern Alaska, the YukonKuskokwim Delta Coastal Zone Survey indicated significantly increasing populations for longtailed ducks since 1988 (Platte and Stehn 2005, p. 6).
Longtailed ducks have the most complex molt of any waterfowl species, with three different plumages (basic, supplemental, and alternate) during the year; plumage is changing almost continuously. In winter and spring, male plumage is mainly white with a black ear patch, black collar around the breast, completely dark wings, and dark central tail feathers; the male has a short dark bill with a pink subterminal band. In early spring and early summer, males appear mostly dark, with a pale gray facial patch. By midsummer, males have gray flanks and buff on their wings. The pattern of plumage change in the female is similar to that of the male, lighter in winter and darker in summer, but lacks the sharp contrast of dark and white, thus appearing darker than the male in winter plumage. Females also do not possess long central tail feathers. Juveniles resemble females but are duller, and the white areas are less distinct than in adult plumages. There are no recognized subspecies or geographic variations.
Longtailed ducks nest in small clusters in subarctic and arctic wetlands on lake islands and by ponds in open tundra and taiga, rarely to tree line; offshore islands with freshwater ponds and tundralike vegetation are also used. Nests are usually in upland habitat, concealed in vegetation, and close to fresh water with emergent vegetation (Arctophila spp. or Carex spp.) for cover, and open deep water for feeding. Nest site selection may be influenced by predation pressure from foxes (Vulpes spp. and Alopex spp.), gulls (Larus spp.), ravens (Corvus corax), and jaegers (Stercorarius spp.). Longtailed ducks avoid nesting on ponds where herring gulls (Larus argentatus), Pacific loons (Gavia pacifica), and common eiders (Somateria mollissima) nest (Robertson and Savard 2002, pp. 5, 1213).
While male longtailed ducks defend a territory, females are not territorial at any stage. Although information on the mating system is scarce, site fidelity of males and females to breeding grounds suggests longterm monogamy. Data from Hudson Bay (Alison 1975, pp. 10, 43) indicate that females show a strong tendency to return to their previous nest area and suggest some level of subadult female philopatry to natal breeding areas as well.
A diurnal feeder, the longtailed duck dives for food and has a highly variable diet of animal prey, focusing on locally abundant food items. Diving to depths greater than 60 meters (196.8 feet), it is probably the deepest diver among waterfowl (Robertson and Savard 2002, p. 6). On breeding grounds, its diet consists mainly of larval and adult aquatic insects, crustaceans, fish roe, and vegetable matter. On marine wintering grounds, epibenthic crustaceans, amphipods, mysids, isopods, bivalves, gastropods, fish, and fish eggs are important in the diet; amphipods, fish, mollusks, and oligochaete worms make up the diet on freshwater wintering grounds (Robertson and Savard 2002, p. 7).
Nest sites, selected by the female, are generally close to water on islands in freshwater ponds, on mainland tundra, in marshy habitat, in scrubland (Salix spp. and Betula spp.), and in dry uplands. Alison (1975, p. 43) documented nest reuse for three successful females. Between six and eight smooth, pale gray to olive buff eggs are laid between late June and late July, depending on location and weather, particularly snow melt. Hatching occurs after 2429 days of incubation (by the female only), between early July and early August. Ducklings are precocial, and leave the nest 12 days after hatching, feeding on material that surfaces when the female dives. The female will lead broods to new ponds when food resources become depleted in the occupied pond. Hens and broods tend to use lakes without fish and may use 1020 different ponds during the prefledging period. Young birds fledge 35 40 days after hatching. Renesting following nest failure is not documented in this species and is unlikely at high latitudes.
Mean annual survival rate of adult females in Alaska is estimated
to be 75 percent (+8 Standard Error (SE)) (Robertson and Savard 2002,
p. 15). In Iceland, mean annual survival of banded adults is 72 percent
(Robertson and Savard 2002, p. 15). Although little information is
available, first breeding is thought to begin at age 2 years, but first
attempts to breed are likely unsuccessful. Periodic nonbreeding may
occur, although it is poorly documented. Longtailed ducks are thought to be longlived; band recovery
data include a male at least 15 years old recovered alive and a male at least 18 years old that had been harvested.
Very little data are available on percent of eggs that eventually result in fledged young, fledging success of hatched young, or mean number of young fledged per nest attempt. Nest success ranges from 41.3 percent in western Alaska to 58.9 percent in northern Manitoba (Robertson and Savard 2002, p. 14). Duckling success in western Alaska is reported to average 9 percent (Robertson and Savard 2002, p. 14). In North America during years with warmer arctic temperatures, more immature birds are harvested, suggesting that temperatures influence reproductive success. In northern Sweden, the proportion of females that reared at least one brood to fledging was higher in years with abundant small rodents (Lemmus spp. and Microtus spp.) (Robertson and Savard 2002, p. 15).
The longtailed duck is a shorttomediumdistance migrant that stages in the thousands at traditional coastal locations before migrating north. Northerly movements begin in late February in western North America and late March on the east coast of North America (Robertson and Savard 2002, p. 4; Wilbor 1999, p. 16). Northward migration from the Great Lakes area begins in late February. Birds travel along the northeast Alaska coast from late May to midJune, and move inland to nesting areas from Baffin Bay during midto late June. Large flocks make use of ice leads in the Arctic until breeding areas become available for nesting. Birds arrive on the breeding grounds from midMay in southerly areas to June in arctic Alaska, Baffin Island, and Ellesmere Island (Robertson and Savard 2002, p. 4).
Postbreeding males begin moltingmigration midJune in Manitoba and late June along the north Alaska coast. Subadults leave Arctic Coastal Plain breeding areas by late June. Females migrate to molting sites several weeks after males in midto late August. Small molting populations are thought to occur throughout most of the breeding range. Major molting habitats in the Beaufort Sea occur near St. Lawrence Island and in coastal lagoons on the west and north coasts of Alaska. Other important molting sites, with concentrations numbering 30,000 to 40,000 individuals, are located between Prudhoe Bay and Demarcation Bay. A large number of birds molt along the coasts of western Baffin Bay. North American breeders may also molt in coastal eastern Russia and northwestern Greenland (Robertson and Savard 2002, p. 5).
Longtailed ducks winter in either offshore marine habitat or inland freshwater areas. Southerly migration begins in late fall with arrival at the Pacific coast, Great Lakes, and Atlantic coast wintering areas in October. Resident populations may exist in Alaska and Hudson Bay (Robertson and Savard 2002, p. 4). Migration routes are both marine (coastal and up to 160 kilometers (km) (99.4 miles (mi)) from offshore) (Fischer, et al. 2002, p. 76) and overland. Few longtailed ducks have been banded, making it difficult to determine affiliations between breeding and wintering locations. Breeding birds banded in northern Manitoba were found to winter primarily in the Great Lakes and to a lesser extent on the Atlantic Coast (Chesapeake Bay). Birds banded in Alaska have never been recovered on the Atlantic Coast (Robertson and Savard 2002, p. 5).
Although there may be two or more geographic populations of long tailed ducks in North America that are separated by the breeding and wintering distribution, the delineation of these populations is not documented (USFWS 2001, p. 45). Traditional band recovery data are insufficient to determine the relationship between breeding, molting, migrating, and wintering groups of longtailed ducks across their distribution.
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: (A) The present or threatened destruction, modification, or curtailment of habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. In making this finding, we evaluated whether threats to the longtailed duck presented in the petition and other information available in our files at the time of the petition review reasonably indicate that listing the longtailed duck may be warranted. Our evaluation of these threats is presented below. In the discussion below, we have evaluated the threats listed in the petition under the most appropriate listing factor.
Certain aspects of longtailed duck ecology and demography should be considered when evaluating the species' status and threats. When compared with dabbling (Anatini) and diving (Aythyini) ducks, long tailed ducks are considered Kselected species. Healthy populations of Kselected species are characterized by delayed sexual maturity, low annual recruitment, relatively low and variable breeding propensity, and high adult survival. Low annual productivity rates and high annual survival rates balance to ensure that individuals replace themselves with offspring that survive to recruit into the breeding population. Although factors that compromise productivity can cause populations to decline, population growth rates are most sensitive to changes in adult survival (Goudie, et al. 1994, p. 30). Kselected species will decline in abundance most rapidly if adults are removed from the population prior to replacing themselves (i.e., if adult survival is decreased). A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
The petitioner listed, but did not discuss in detail or provide supporting biological data, the following reasons for the petition that may be addressed under Factor A: increasing oil exploration and development and associated oil spills, removal of biomass from the marine environment by fishing in the North Pacific, and ``mussel beds.'' Only the indirect, habitatrelated effects to longtailed ducks of oil spills and operational waste discharges are discussed under Factor A; direct effects to longtailed ducks from exposure to oil and operational wastes will be discussed in Factor E. Lacking more specific information, we interpreted the term ``mussel beds'' to refer to potential competition with nearshore marine aquaculture facilities. The petitioner provided no supporting information to support these claims; therefore, we relied on information in Service files to clarify these potential threats.
No direct measures of habitat degradation are available (Robertson and Savard 2002, p. 18), nor is habitat loss (nesting, molting, or wintering) implicated as a factor influencing the Bering/Pacific or North American longtailed duck population decline (Wilbor 1999, p. 49).
Several sources cite oil pollution as a threat to marine birds in
general and longtailed ducks in particular [in Alaska (Wilbor 1999, p.
51; USFWS 2003, p. 51); in the North Sea (International Council for the [[Page 34690]]
Exploration of the Sea 2004, p. 24); in the Baltic Sea (Laine and Backer 2002, p. 2); in Britain and Ireland (Kirby, et al. 1993, p. 123); and globally (Robertson and Savard 2002, p. 17)]. However, most are concerned with the acute mortality phase of exposure to oil (to be discussed under Factor E), and none reported any evidence of longterm effects on longtailed duck populations due to habitat degradation.
Franson, et al. (2004, p. 504) analyzed blood from longtailed ducks collected at nearshore islands in the vicinity of Prudhoe Bay and at a reference site for trace elements to compare contaminant levels in sea ducks using the marine environment near the Prudhoe Bay oil fields. In marine ecosystems, persistent contaminants, including trace elements and organochlorines, reach their greatest concentrations in coastal regions, and, except for selenium, concentrations of metals in blood were low and were not consistently higher at one location (Franson, et al. 2004, pp. 504505).
Flint, et al. (2003, p. 38) utilized nearshore and offshore aerial surveys, as well as groundbased studies, in both industrialized and control areas to evaluate how longtailed ducks may be affected by industrialization. Their data demonstrated that, even when flightless, longtailed ducks moved considerable distances. There was little evidence of displacement of individuals associated with disturbance; rather, patterns of movements were thought to be primarily influenced by weather conditions, particularly wind direction. Further, declines in duck numbers in the seismic area could not be attributed to underwater seismic activities, as similar changes in aerial survey counts and lagoon movements were observed in both the industrial and control areas (Flint, et al. 2003, p. 55).
The potential for competition with mussel aquaculture in the nearshore environment is limited to areas where overwintering long tailed ducks and marine aquaculture overlap, and is anticipated to be low due to the broad diversity of the winter diet of the species (Robertson and Savard 2002, p. 7). Additionally, aquaculture sites may present an attractive foraging site for longtailed ducks.
The removal of biomass from the marine environment through overfishing of herring and other species may reduce the availability of spawn for migrating longtailed ducks (Robertson and Savard 2002, p. 18); however, no correlation between these indirect impacts and long tailed duck population trends has been documented.
Increasing oil exploration and development and associated oil
spills, removal of biomass from the marine environment by fishing in
the North Pacific, and ``mussel beds,'' as identified by the
petitioner, are all potential habitatrelated threats to the long
tailed duck. However, no evidence of longterm effects on longtailed
duck populations due to habitat degradation or loss has been
documented. We find that the petition does not present substantial
scientific or commercial information indicating that listing the long
tailed duck as endangered may be warranted due to the present or
threatened destruction, modification, or curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
The petitioner asserts that subsistence harvest is increasing, and collection by museums continues despite population declines. The petitioner provided no information to support these statements; therefore, we relied on information in Service files to clarify these potential threats.
The majority of longtailed ducks harvested during the migratory game bird season are taken on the Atlantic Coast. Alaska accounts for approximately 2 percent of the total harvest of approximately 14,500 birds (Trost and Drut 2002, p. 28), which is less than 1 percent of the world population. Wilbor (1999, p. 51) estimated the total longtailed duck subsistence harvest in the Alaska/Pacific flyway to be 11,000 birds annually (plus 1,000 during the migratory game bird season); however, Service data (Alaska Migratory Bird CoManagement Council 2007) and Trost and Drut (2002, p. 28) reported much lower harvest levels: fewer than 5,000 (subsistence) and fewer than 500 (sport). Based on an annual take of 12,000 birds, Wilbor (1999, p. 51) estimated that about 2 percent of the total Bering/Pacific longtailed duck population is harvested annually and concluded that the impact on the population dynamics of this segment of the population was low. Although the longtailed duck is believed to be an important species in the eastern Russian commercial sea duck harvest (Goudie, et al. 1994, p. 36), no information is available on the Russian and Japanese harvests. A review of migratory game bird harvest data reported by Trost and Drut (2002, p. 28) indicates that harvest of longtailed ducks in Alaska has remained relatively stable between 1966 and 2001, as has subsistence harvest of the species in Alaska (Wentworth and Wong 2001, p. 96). Finally, Robertson and Savard (2002, p. 18) report scientific research activities have no obvious impacts.
Accordingly, we find that the petition does not present substantial scientific or commercial information indicating that listing the long tailed duck as endangered may be warranted due to overutilization of longtailed ducks for commercial, recreational, scientific, or educational purposes.
C. Disease or Predation
The petition does not provide information or state that disease or predation is a threat to the species. In addition, there is no information in our files to indicate that disease or predation is a threat to the longtailed duck.
D. Inadequacy of Existing Regulatory Mechanisms
The petitioner lists lack of protection under the Migratory Bird Treaty Act (16 U.S.C. 703712), inadequacy of existing regulatory mechanisms, increased hunting pressure on longtailed ducks due to bag limit reductions on dabbler and goose species, unchanged bag limits despite population declines, and legalization of the spring subsistence hunt as threats to the species. The petitioner provided no additional evidence to support these claims; therefore, we relied on information in Service files to clarify these potential threats.
The longtailed duck is not currently listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), nor is it included on the International Union for the Conservation of Nature (IUCN) Red List (Threatened Animals of the World) (Wilbor 1999, p. 3). No specific State or provincial designation has been given to the longtailed duck in the United States, Northwest Territories, Yukon Territory, Canada, or Russia (Wilbor 1999, p. 4).
The longtailed duck is protected under the Migratory Bird Treaty
Act of 1918 (MBTA) in the United States, and is covered by treaties
with Canada, Russia, and Japan. Unless permitted by regulations, the
MBTA provides that it is unlawful to pursue, hunt, take, capture or
kill, possess, sell or purchase, or transport or export any migratory
bird, part, nest, egg or product. The MBTA grants the Secretary of the
Interior the authority to establish hunting seasons for any of the
migratory game bird species, including the longtailed duck, listed in
the MBTA. The Fish and Wildlife Service has determined that hunting is appropriate
only for those species for which hunting is consistent with population status and longterm conservation. The Fish and Wildlife Service annually publishes migratory game bird regulations in the Federal Register. State and provincial game laws formulated in conjunction with the Fish and Wildlife Service and Canadian Wildlife Service establish bag limits and seasons. In Canada and Russia, longtailed duck sport hunting is managed under hunting regulations set forth by the Canadian Wildlife Service and the Russian Ministry of Environment and Natural Resources, respectively.
Monitoring requirements of the MBTA, the fall/winter migratory game bird hunting regulations, and the spring/summer subsistence harvest regulations provide mechanisms to limit the harvest of longtailed ducks if necessary for population regulation. We have no documented information that these mechanisms will not adequately protect long tailed duck populations.
Accordingly, we find that the petition does not present substantial
scientific or commercial information indicating that listing the long
tailed duck as endangered may be warranted due to the inadequacy of existing regulatory mechanisms.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Threats listed by the petitioner that may be addressed under Factor E include increased oil spills due to offshore drilling and ``the climatic decadal oscillation.'' The discussion of oilrelated effects under this factor will be limited to the acute, direct effects to long tailed ducks from exposure to oil. Indirect effects of habitat degradation resulting from offshore oil development and oil spills are discussed above under Factor A. Furthermore, as the petitioner provided no additional information to support these claims, we relied on information in Service files to clarify these potential threats.
Stehn and Platte (2000, p. 1) constructed a spatial model by overlaying bird density estimates with predicted spill trajectories. Spills of various sizes were used to estimate the potential effects of an offshore spill from the proposed Liberty Project in the nearshore Beaufort Sea. Their model predicted that the average number of birds that would be exposed to oil in the event of a spill at the site was greatest for longtailed ducks (as high as 2,062) and that the average proportion of the total longtailed duck population in the study area that would be exposed to oil in the event of a spill at the site was between 3 percent and 9 percent, and may approach 19 percent.
The petitioner did not define the term ``Pacific Decadal Oscillation'' or identify specific concerns regarding the relationship between this mode of interdecadal climatic variation and longtailed duck populations. Hare and Mantua (2000, p. 105) describe the Pacific Decadal Oscillation (PDO) as a longlived El Ni[ntilde]o (ENSO)like pattern of Pacific climate variability that explains variations in the Pacific Basin and North American regions. The PDO is characterized by fluctuations between warm and coldwater regimes.
No data exist evaluating the relationship between longtailed duck productivity, survival, or population trends and largescale climate patterns. Species like the longtailed duck have the ability to exploit a wider range of habitats and food sources, are less sensitive to early stages of ice formation, and respond to persistent ice cover in the nearshore zone by concentrating in offshore areas (Zydelis 2001, p. 307). Zydelis and Ruskyte (2005, p. 139) found body condition and fat reserves in winter to be equivalent between longtailed ducks feeding primarily on mollusks and those feeding on mobile, energyrich food items such as crustaceans.
The possible effects of exposure to oil on longtailed ducks are thought to be localized, and have not been implicated in global population declines. Additionally, no localized longtailed duck declines have been documented. While climate patterns and oceanographic conditions are important factors influencing longtailed duck habitat, food resources, and distribution, the relative ecological plasticity of the species in selecting winter habitat and food suggests it is less sensitive to interannual and interdecadal climatic variability (Zydelis and Ruskyte 2005, p. 139) than other sea ducks. In spite of potential localized impacts resulting from oil spills, the longtailed duck remains the most abundant arctic sea duck and continues to occupy historical breeding and wintering ranges. For these reasons, we believe the impact of these potential threats on the population dynamics of this species is negligible. Therefore, we find that the petition does not provide substantial scientific or commercial information indicating that listing the longtailed duck as endangered may be warranted as a result of increased oil spills due to offshore drilling and ``the climatic decadal oscillation'' or any other natural or manmade factors affecting the species' continued existence.
Significant Portion of the Range
The petition does not specify a population of concern, it does not articulate that the longtailed duck should be listed in any particular portion of its range, and it does not specify any particular portion of the species' range that it maintains is significant. Therefore, we based our threats analysis on the entire range of the species. Nearly all of the threats identified in the petition appear to be potential threats which could occur, rather than actual threats, with no documented correlation between these potential threats and impacts on longtailed duck populations. Our threats analysis does not find substantial information to indicate that any of the five factors poses a threat to the longtailed duck. If we were to determine in the future that the longtailed duck is threatened or endangered in a significant portion of its range, we would add the species to the candidate list and propose its listing.
We have reviewed and evaluated the five listing factors with regard to the longtailed duck, based on the information in the petition and available in our files. On the basis of this review and evaluation, we conclude that the petition does not present substantial scientific or commercial information to indicate that listing the longtailed duck as endangered under the Act may be warranted.
While the petitioner did not provide detailed information on the
abundance or geographic distribution of the longtailed duck,
information in Service files indicates that the longtailed duck is
currently numerous and widespread. Its breeding range has not
contracted. The information provided in the petition on the potential
impacts to the species caused by offshore oil exploration and
development, removal of biomass due to fishing, and potential
competition with nearshore marine aquaculture is inadequate to
determine that these activities are destroying or modifying habitat in
a manner and at a level that affects the species to such an extent that
a reasonable person could conclude that listing may be warranted.
Likewise, evidence in our files concerning hunting (both sport and
subsistence), collecting by scientific institutions, and oil spill
losses does not provide substantial information to support a conclusion
that listing the species may be warranted. No data exist evaluating the
relationship between longtailed duck productivity, survival, or
population trends and largescale climate patterns such as Pacific [[Page 34692]]
Decadal Oscillation. We also found the evidence in our files inadequate to corroborate the petitioner's assertion that the MBTA may not be an effective regulatory mechanism, because under the MBTA, the harvest of longtailed ducks is regulated and monitored.
After reviewing and evaluating the petition and information available in our files, we find that the petition does not present substantial scientific or commercial information to indicate that listing the longtailed duck as endangered may be warranted at this time. Although we will not commence a status review in response to this petition, we will continue to monitor the longtailed duck population status and trends, potential threats, and ongoing management actions that might be important with regard to the conservation of the long tailed duck. If you wish to provide information regarding the long tailed duck, you may submit your information and materials to the Anchorage Fish and Wildlife Field Office (see ADDRESSES).
A complete list of all references cited in this document is available, upon request, from the Anchorage Fish and Wildlife Field Office (see ADDRESSES).
The primary author of this document is staff of the Anchorage Fish and Wildlife Field Office (see ADDRESSES).
The authority for this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.)
Dated: June 12, 2008.
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E813840 Filed 61708; 8:45 am]
BILLING CODE 431055P
FOR FURTHER INFORMATION CONTACT
Mr. Greg Balogh, Endangered Species Branch Chief, Anchorage Fish and Wildlife Field Office, (see ADDRESSES); by telephone at 9072712778; or by facsimile at 907271 2786. Persons who use a telecommunications devise for the deaf (TTD) may call the Federal Information Relay Service (FIRS) at 8008778339.