Brachyramphus brevirostris

This species may be more closely related to B. marmoratus (marbled murrelet) than to B. perdix (long-billed murrelet) (AOU 1998).

Analyses of genetic data (allozymes, cytochrome b gene, and control region of mtDNA) suggest very low rates of immigration and emigration between Kittlitz's murrelets in the western Aleutian Islands and mainland birds from Kachemak Bay on the Kenai Peninsula (Friesen et al. 1996, MacKinnon 2005). Data presented by Birt et al. (2010) suggests that there may be significant differentiation among geographically separated populations.

Range confined mainly to Alaska; long-term survey efforts suggest that, in at least some areas, Kittlitz's murrelets have suffered significant population declines over past decades, but declines may be beginning to subside in some areas; potentially threatened by pollution and directly or indirectly by fishing; glacial retreat and oceanic regime shifts may have caused population declines.

Breeding range includes Alaska (supports the vast majority of the known population) and the Russian Far East (Day et al. 1999, USFWS 2010). Summer distribution often is associated with proximity to tidewater glaciers (Day et al. 1999), but this species also occurs in marine habitats not currently influenced by glaciers, such as around Kodiak Island, the Aleutian Islands, Bristol Bay, Seward Peninsula, Cape Lisburne, and the Chukotka and Kamchatka peninsulas in Russia (Day et al. 1999; USFWS 2010; J. Piatt, pers. Com., cited by USFWS 2010).

During the breeding season, Kittlitz's murrelets in Alaska primarily occur in four regions: Southeast Alaska, Southcentral Alaska, Aleutian Islands, and Alaska Peninsula; northwestern Alaska is likely an additional breeding season concentration area (USFWS 2010).

Distribution and abundance information for the Russian Far East is scarce. A small number of nests have been documented: on the Chukotka Peninsula, in northeastern Kamchatka, and on the coast of the Sea of Okhotsk (Kondratyev et al. 2000). In the late 1990s large numbers of Kittlitz's murrelets were reported from the Kamchatka Peninsula (Vyatkin 1999). The summer range extends from the coastal waters of Wrangel Island in the East Siberian Sea, along the coast of the Chukotka Peninsula, to the southern tip of Kamchatka, and westward to the Sea of Okhotsk (Kondratyev et al. 2000; Artukhin et al. 2010). During breeding season, Kittlitz's murrelets are commonly found along a 3-km-wide strip of coastal waters from the Chukotka to Kamchatka Peninsulas (Vyatkin 1999, Artukhin et al. 2010).

The winter range is not well known but is probably pelagic (open ocean) (Day et al. 1999). Occasional winter sightings occur in southeast and western Alaska, and the species may be locally common in a few locations in southcoastal Alaska (Kendall and Agler 1998, Day et al. 1999, Kissling et al. 2010). Kittlitz's murrelets have been observed in winter in the protected waters of Prince William Sound, Kenai Fjords, Kachemak Bay, Kodiak Island, Yakutat Bay, Sitka Sound, and the mid-shelf regions of the northern Gulf of Alaska (Kendall and Agler 1998, Day et al. 1999, Day and Prichard 2001, Stenhouse et al. 2008, Kissling et al. 2010). Polynyas (areas of open water surrounded by sea ice) southwest of St. Lawrence Island, as well as east of the Pribilof Islands and southeast of St. Matthew Island, may be important wintering areas (Kuletz and Lang 2010). Winter range in Asia is largely unknown, but observations have been reported from the Kamchatka Peninsula and the Kuril Islands in the Russian Far East (Flint et al. 1984). A few birds have been observed during late winter in the Sireniki polynya of southern Chukotka in Russia (Konyukhov et al. 1998). [Source: USFWS 2010]

The number of distinct occurrences (subpopulations) is poorly known. The remote and solitary nesting habits lead to extreme difficulty in finding nests. Low nesting densities and a preference for difficult-to-reach talus slope nesting areas contribute to the fact that about two dozen nests have been found (USFWS 2002).

USFWS (2010) summarized threats as follows: "At this time, the ultimate cause for the population decline of Kittlitz's murrelet is unknown. It appears the decline may be waning in some portions of its range in recent years. Major threats to Kittlitz's murrelets appear to be habitat based, caused by one or a combination of mechanisms including: change to forage fish quality and availability due to rapid atmospheric and/or decadal oceanic climate change, contamination of the marine environment, reduced nesting habitat due to primary succession following glacial recession, and reproductive failure as a result of weather, starvation, and predation pressures. Additive to this underlying stress to the population may be adult mortality from incidental bycatch in commercial fisheries, disturbance by tour boats, and adult predation."

Present threats include:

1) Marine oil pollution. This species is considered to be extremely sensitive to this form of pollution by the U.S. Fish and Wildlife Service.

2) Decreases in food stock. Changes in the forage-fish populations from the North Pacific food web have been linked to decreases in marine vertebrates. Murrelet numbers may also decline as a result of shifts in forage-fish distribution.

3) Gill net fisheries. Mortality rates appear to be increasing due in part to gill-net by-catch. In a study in PWS in 1990 and 1991, a greater proportion of Kittlitz's Murrelets were taken in gill nets than Marbled Murrelets, compared to their populations. These rates are more significant in the Prince William Sound and off the Copper River Delta.

4): Melting of glaciers. The disappearance of coastal glaciers due to global warming may have a long term effect on the population. This species has a strong tie to these ecosystems and it is unclear how they will be influenced by the shrinking of these habitats (van Vliet 1993). In PWS, declines and distribution of Kittlitz's Murrelets were correlated with retreating glaciers, and fjords with more stable glaciers (mainly in northwest PWS) now support most of the populations in PWS (Kuletz et al. 2003).