abstracts of oral and poster presentations - Pacific Seabird Group

winter, lower ice concentrations were also associated with King Eider locations. This study provides some of
the first large-scale descriptions of King Eider migration and habitat use outside of the breeding season.
GLOBAL CLIMATE CHANGE AND ABLATION OF THE GLACIER MURRELET
John F. Piatt 1 (john_piatt@usgs.gov) and Kathy Kuletz 2 ; 1 USGS Alaska Science Center, Anchorage, AK USA;
2 USFWS, Migratory Bird Management, Anchorage, AK USA
Cooling climate in the late Pliocene was accompanied by rapid speciation among the Alcidae. Several
new species of Brachyramphus murrelets evolved, and one that survived to our time, Kittlitz’s Murrelet (B.
brevirostris), developed an unusual and intimate association with glacial ice during the Pliocene and subsequent
Pleistocene ice ages. Kittlitz’s Murrelets usually nest in the high alpine, on recently deglaciated mountain
peaks, and forage in glacially modified marine waters. Today, the “Glacier Murrelet” is found only in areas
with extensive ice sheets (e.g., Glacier Bay NP, outer coast of Wrangell–St. Elias NP, Prince William Sound,
Kenai Fjords NP, Kachemak Bay), remnant glaciers (e.g., Alaska Peninsula, a few Aleutian islands), and in a
few areas that once contained extensive ice fields but are now glacier free (e.g., Seward Peninsula). Surveys
conducted in areas containing the bulk of their numbers in Alaska indicate that populations have declined by
>80–90% during the past 15 years. This corresponds to an almost universal and increasingly rapid recession of
glaciers and ice fields throughout Alaska, which itself is a result of global warming.
STATUS OF MARBLED MURRELET POPULATIONS IN ALASKA
John F. Piatt 1 (john_piatt@usgs.gov) and Kathy Kuletz 2 ; 1 USGS Alaska Science Center, Anchorage, AK USA;
2 USFWS, Migratory Bird Management, Anchorage, AK USA
Estimated entirely from surveys at sea, the total population of Marbled Murrelets (MAMU) in Alaska
during the early 1990s was probably in the order of half a million birds. Some population surveys were repeated
using the same methods each year, so we can assess population trends in a few areas. At Glacier Bay in SE
Alaska (where 100,000s of murrelets resided historically), summer populations of MAMU declined by 75%
between 1991 and 1999/2000, with a 17.5% per annum rate of decline (P < 0.05). Other than Kittlitz’s Murrelet
(–18.8% pa), populations of all other species of marine birds are stable or increasing. In Prince William Sound
(10,000s of murrelets), summer populations of MAMU declined by 85% since a single census in 1972 and by
about 65% since repetitive annual surveys began in 1989 (a –6.6% pa decline since 1989; P < 0.01). Along the
Kenai Peninsula (1,000s of murrelets), summer populations declined by 62% from 1976 to 1989 but increased 5-
fold between 1989 and 2002. Counts of wintering murrelets on surveys around Kodiak (annually since 1980)
and on Christmas Bird Counts show no trends but suggest cyclical patterns of winter attendance, perhaps related
to climate. We will discuss threats to MAMU populations and possible causes for the alarming decline in their
summer breeding populations.
LARGE-SCALE BREEDING FAILURE AT A CENTRAL CALIFORNIA COMMON MURRE COLONY
DUE TO COMMON RAVEN AND BROWN PELICAN DISTURBANCE AND PREDATION [Poster]
Travis B. Poitras 1 (tbp7001@humboldt.edu) and Gerard J. McChesney 2 ; 1 Department of Wildlife, Humboldt
State University, Arcata, CA USA; 2 U.S. Fish and Wildlife Service, San Francisco Bay NWRC, Newark, CA
USA
In 1996, a collaborative restoration project was implemented to restore Common Murre colonies along
the central California coast that were impacted by oil spills. The resulting monitoring at one colony, the
Castle/Hurricane Colony Complex, has documented periodic disturbance by juvenile Brown Pelicans on
breeding murres since 1997. Disturbance events have contributed both directly and indirectly to egg and chick
loss within the colony. In 2003, a pair of Common Ravens began harassing the colony, causing several flushing
events and depredation of at least three chicks. In 2004, frequent disturbance by nesting ravens caused the
abandonment of one murre subcolony before egg-laying and high levels of egg depredation. Also, during the
late incubation/mid-chick period in 2004, a juvenile pelican almost continuously harassed murres on several
nesting rocks over a period of nine days. Flushing events exposed eggs and chicks, many of which were taken
by ravens and gulls, and led to nearly complete reproductive failure on six of eight murre subcolonies. These