abstracts of oral and poster presentations - Pacific Seabird Group

NESTING BEHAVIOR AND REPRODUCTIVE SUCCESS OF NEWELL'S SHEARWATERS
Brenda J. Zaun (Brenda_Zaun@fws.gov) and Michael M. Hawkes (Mike_Hawkes@fws.gov); U.S. Fish and
Wildlife Service, Kauai National Wildlife Refuge Complex, Kilauea, Kauai, HI USA
Newell's Shearwaters (Puffinus auricularis newelli) nest primarily on steep, inaccessible slopes of the
interior mountains of Kauai, Hawaii. However, two pairs nested in artificial burrows near the coast at Kilauea
Point National Wildlife Refuge, providing a rare opportunity to gain information on their nesting ecology. We
present data on breeding, nesting, and chick provisioning behavior not previously described. Newell's
Shearwaters arrive on island mid- to late April, excavate a burrow, copulate, depart on a pre-laying exodus, then
return to lay one egg in late May to early June. The male assumes the first of six incubation shifts and will
incubate for a longer period than the female. Incubation intervals averaged 10.2 days, and incubation periods
were 53 and 54 days for the two nests in 2004. The newly hatched chicks were attended throughout each night
and intermittently during the day up to 6 days. Thereafter, at least one parent visited most nights until the chicks
fledged (81 to 94 days). Parents exhibited amazing synchrony in nightly returns to the chick, with females
returning for 6 to 7 consecutive nights and males for 7 to 10 consecutive nights. Chick weights were taken
several times/week and compared among years. The chicks of 2003 averaged a higher overall weight than the
chicks of 2004 and fledged earlier.
RESULTS OF BEACHED-BIRD SURVEYS IN THE EASTERN BALTIC
Ramûnas Zydelis (rzydelis@sfu.ca); Institute of Ecology of Vilnius University, Vilnius LITHUANIA; (current)
Centre for Wildlife Ecology, Simon Fraser University, Burnaby, BC CANADA
Beached-bird surveys were conducted during 1991–2003 along the Lithuanian coast of the Baltic Sea. Stranded
bird densities averaged 0.3 carcasses/km shoreline; however, densities varied between different sections of the
coast. About 27% of bird carcasses had oiled plumage. No temporal trends were detected in beached-bird
densities and oiling rates in the course of the study. Beached-bird species-composition, however, significantly
changed, with decreasing proportions of gulls and an increasing share of diving birds. A number of birds were
identified as drowned in gillnets of a nearshore fishery that started and developed rapidly during the study
period. The proportion of birds that died in fishing nets increased remarkably during the study period and
correlated with the increased proportion of diving birds. Additional bird mortality by the gillnet fishery
obscured interpretation of beached-bird survey results in relation to chronic oil pollution because it was often
difficult to identify whether birds died in fishing nets or due to other reasons. Temporal and spatial variation of
fishing effort also did not allow an assumption of constant mortality rate due to this reason.