during incubation <strong>and</strong> guard stage. Further study may allow refinements that improve the precision <strong>and</strong> consistency <strong>of</strong> the technique. POPULATION GENETIC STRUCTURE AND CONSERVATION OF MARBLED MURRELETS Vicki L. Friesen 1 (friesenv@biology.queensu.ca), T. P. Birt 1 , G. Gissing 1 , John F. Piatt 2 , Richard T. Golightly 3 , Percy N. Hébert 3 , Scott H. Newman 4 , <strong>and</strong> B. C. Congdon 5 ; 1 Department <strong>of</strong> Biology, Queen’s University, Kingston, ON CANADA; 2 U.S. Geological Survey, Alaska Biological Sciences Center, Anchorage, AK USA; 3 Department <strong>of</strong> Wildlife, Humboldt State University, Arcata, CA USA; 4 Wildlife Trust, Palisades, NY USA; 5 School <strong>of</strong> Tropical Biology, James Cook University, Cairns AUSTRALIA Genetic data are needed to help delineate management units for Marbled Murrelets (Brachyramphus marmoratus). We compared variation in the mitochondrial control region, four nuclear introns, <strong>and</strong> three microsatellite loci among 194 murrelets from throughout their range. Results <strong>of</strong> several types <strong>of</strong> analyses on all three types <strong>of</strong> markers indicate that significant population genetic structure exists within this species: several control-region haplotypes <strong>and</strong> intron alleles were unique to the Aleutian Isl<strong>and</strong>s or California; global estimates <strong>of</strong> population structure were statistically significant, as were many pairwise estimates; <strong>and</strong> marked isolation-bydistance effects were found. Results indicate that Marbled Murrelets include at least four management units: (1) Aleutian Isl<strong>and</strong>s, (2) Alaska Peninsula, (3) Kodiak Isl<strong>and</strong> to British Columbia <strong>and</strong> possibly northern California, <strong>and</strong> (4) central <strong>and</strong> possibly northern California. The possibilities that the Aleutian Isl<strong>and</strong>s <strong>and</strong> California include two or more distinct populations each, the ecological exchangeability <strong>of</strong> tree- <strong>and</strong> groundnesting murrelets, <strong>and</strong> the genetic affinities <strong>of</strong> murrelets in Washington <strong>and</strong> Oregon still need to be determined. INTERANNUAL VARIATION IN DIET AND PRODUCTIVITY OF PLANKTON-FEEDING AUKLETS: CLUES TO THE EFFECTS OF CLIMATE CHANGE Adrian E. Gall 1 (galla@onid.orst.edu), Daniel D. Roby 1 , Ian C. Rose 1 , <strong>and</strong> David B. Irons 2 ; 1 USGS–Oregon Cooperative Fish <strong>and</strong> Wildlife Research Unit, Department <strong>of</strong> Fisheries <strong>and</strong> Wildlife, Oregon State University, Corvallis, OR USA; 2 Migratory Bird Management, US Fish <strong>and</strong> Wildlife Service, Anchorage, AK USA We assessed the relationship <strong>of</strong> productivity to diet in Least Auklets (Aethia pusilla) <strong>and</strong> Crested Auklets (A. cristatella) by measuring breeding chronology, nest survival, <strong>and</strong> nestling diet composition at two colonies on St. Lawrence Isl<strong>and</strong>, Alaska, during the 2000–2002 breeding seasons. These three reproductive parameters varied in parallel among years for both auklet species, suggesting control by a common environmental factor. Median hatching dates for both species were two weeks earlier in the year <strong>of</strong> highest nest survival (2002) than in the two years <strong>of</strong> lower nest survival. Nestlings <strong>of</strong> Least <strong>and</strong> Crested auklets were fed more <strong>of</strong> the oceanic, high-lipid copepod Neocalanus cristatus in 2002 than in the two years <strong>of</strong> lower reproductive success. In contrast, during the year <strong>of</strong> lowest nest survival for both auklet species (2001), the neritic, low-lipid copepod Calanus marshallae was more prevalent in the diet <strong>of</strong> Least Auklets <strong>and</strong> the small copepod N. flemingeri was more prevalent in the diet <strong>of</strong> Crested Auklets than in the two years <strong>of</strong> higher nest survival. Sea ice-dependent advection <strong>of</strong> oceanic copepods far onto the shelf <strong>of</strong> the northern Bering Sea appears to be a key determinant <strong>of</strong> auklet nesting success at St. Lawrence Isl<strong>and</strong>. Auklet productivity <strong>and</strong> diet may serve as one component <strong>of</strong> the overall effort to monitor the impact <strong>of</strong> climate change on productivity <strong>of</strong> the northern Bering Sea. A REVIEW OF COMMENSAL RODENT ERADICATIONS ON ISLANDS Juan-Pablo Galván* 1 (jgalvan@isl<strong>and</strong>conservation.org), Bernie Tershy 1 , Gregg Howald 1 , Araceli Samaniego 1 , Brad Keitt 1 , Michael Browne 2 , James Russell 2 , Michel Pascal 3 , <strong>and</strong> John Parkes 4 ; 1 Isl<strong>and</strong> Conservation, Santa Cruz, CA USA; 2 IUCN SSC Invasive Species Specialist <strong>Group</strong>; 3 Institut National de la Recherche Agronomique, FRANCE; 4 L<strong>and</strong>care Research, NEW ZEALAND Introduced species are responsible for most bird extinctions <strong>and</strong> are the largest cause <strong>of</strong> seabird extinctions <strong>and</strong> endangerment. Commensal rodents (Rattus spp. <strong>and</strong> M. musculus) are the most widespread <strong>and</strong> damaging <strong>of</strong> the introduced mammals. They are directly responsible for an estimated 40% <strong>of</strong> global bird extinctions <strong>and</strong> the extirpation <strong>of</strong> many seabird populations. However, commensal rodents can be eradicated from isl<strong>and</strong>s, after which populations <strong>of</strong> native species can recover. We reviewed all known commensal rodent
eradications from isl<strong>and</strong>s to facilitate future isl<strong>and</strong> conservation actions. The complete data set can be found at http://www.isl<strong>and</strong>conservation.org/eradicationdb.html. Globally, we found at least 274 commensal rodent eradications on 233 isl<strong>and</strong>s, mostly in Australasia. Most eradications (63%; n = 173) have occurred on small isl<strong>and</strong>s (
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