abstracts of oral and poster presentations - Pacific Seabird Group

events demonstrate the sensitivity of nesting murres to avian and other forms of disturbance and pose yet
another threat to this depleted colony. The unusual pelican behavior is still not fully understood.
INLAND PIPING PLOVER MIGRATION STOPOVER SITES: USING BIRDERS’ REPORTS TO STUDY
MIGRATION PATTERNS AND HABITAT USE
Vanessa D. Pompei* 1 (pomp0012@umn.edu) and Francesca J. Cuthbert 2 ; 1 Conservation Biology Program,
University of Minnesota, St Paul, MN USA; 2 Department of Fisheries, Wildlife and Conservation Biology,
University of Minnesota, St. Paul, MN USA
The Great Lakes population of Piping Plovers (Charadrius melodus) has been extensively studied, but
knowledge about migration ecology is limited; this information is needed for recovery. Because the population
is small (~50 breeding pairs), tracking individual birds is not feasible. This study compiled records (e.g., state
atlases, bird journals) of Piping Plover sightings from a “hypothetical migration pathway” used by Great Lakes
birds between winter and breeding sites. Data were used to identify current and historic stopover sites and sites
to visit to study habitat characteristics. Additionally, we examined chronology and spatial patterns of migration
between the breeding and wintering grounds. We located >1,200 fall and spring stopover records and visited
>15 sites to measure habitat characteristics. Results show that Piping Plovers use sites throughout the migration
pathway during both fall and spring. Habitat used was shoreline of reservoirs, natural lakes, and rivers. Finally,
reports indicate that plovers do not concentrate in large numbers at inland stopover sites and that site use is
highly influenced by local water levels and water-management policies.
NEAR-SHORE FORAGING BEHAVIOR OF MARBLED MURRELETS IN SOUTHEAST ALASKA
[Poster]
Kira E. Pontius* 1 (pontius.16@osu.edu) and Matthew Kirchhoff 2 ; 1 The Ohio State University, Columbus, OH
USA; 2 Alaska Department of Fish and Game, Juneau, AK USA
The Marbled Murrelet (Brachyramphus marmoratus) is an alcid that nests in old-growth forests and
lives and forages at sea. Marbled Murrelets are found along the Pacific coast and are considered threatened in
Washington, Oregon, California, and British Columbia but have a relatively large population in Alaska. Our
objectives were to study the near-shore diving behavior of murrelets as compared to populations in threatened
areas and to examine the influence of a pre-dive head crouch on dive times. Observations were made at Point
Bishop, near Juneau, Alaska. Birds were observed from land during all stages of tide and over all daylight hours
on 4 days in mid July. We recorded 2,875 behavioral observations on 240 birds, including 1,289 dives. The
mean dive time was 26.79 s (SD = 9.7 s), and the mean recovery surface time was 11.31 s (SD = 8.7 s). The
pre-dive head crouch was noted present 321 times and absent 387. We examined the relationship between dive
and recovery time and tested the effects of pre-dive head crouch, tidal stage, time of day, and group size on the
dive and recovery surface times.
WHY DO CORMORANT EGGS HAVE LOW MERCURY LEVELS AT HALEJI LAKE (PAKISTAN)
JACANA’S TEST
Francisco J. Ramírez-Benítez 1 , Xavier Ruiz 1 (xruiz@porthos.bio.ub.es), Carolina Sanpera 1 , Lluis Jover 2 , Rahat
Jabeen 3 , and Mauro Fasola 4 ; 1 Dept. de Biologia Animal, Universitat de Barcelona, Barcelona SPAIN; 2 Dept.
de Salut Pública (Bioestadistica), Universitat de Barcelona, Barcelona SPAIN; 3 WWF, Karachi PAKISTAN;
4 Dipto. Biologia Animale, Università di Pavia, ITALY
During a study of the pollution levels by Hg and Se in birds of the Haleji Lake (Pakistan), we observed
that eggs of Little Cormorant (Phalacrocorax niger) showed unexpected significantly lower levels of Hg in
relation to other fish-eating birds (egrets). However, such levels were similar to those in eggs of Pheasant-tailed
Jacanas (Hydrophasianus chirurgus), a surface predator which may include a variable proportion of plant
material in its diet. To assess that such similarity did not derive from similar diets, we used C and N stableisotope
analysis (SIA). Results indicate that jacanas exploited a lower trophic level than cormorants ( 15 N) and
that both species foraged at different places within the lake ( 13 C). We have no data on SIA for egrets, but we
studied their chicks’ diet (mostly fish) and have data for Se levels in their eggs. Se levels discriminate very well
between trophic levels, being significantly higher in cormorants and egrets than in jacanas. Since