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Fatal entanglement in fishing gear is the leading cause of population decline for albatross globally, a consequence of attraction to bait and fishery discards of commercial fishing operations. We investigated foraging strategies of Laysan albatross (Phoebastria immutabilis), as inferred from nitrogen and carbon isotope values of primary feathers, to determine breeding-related, seasonal, and historic factors that may affect the likelihood of association with Alaskan or Hawaiian longline fisheries. Feather samples were collected from live birds monitored for breeding status and breeding success on Midway Atoll in the northwestern Hawaiian Islands, birds salvaged as fisheries-bycatch, and birds added to museum collections before 1924. During the chick-rearing season (sampled April-May), means and variances of stable isotope values of birds with the highest, most consistent reproductive success were distinct from less productive conspecifics and completely different from birds caught in Hawaiian or Alaskan longline fisheries, suggesting birds with higher multi-annual reproductive success were less likely to associate with these fisheries. Contemporary birds with the highest reproductive success had mean values most similar to historic birds. Values of colony-bound, courting prebreeders were similar to active breeders but distinct from prebreeders caught in Alaskan longline fisheries. During the breeding season, δ15N values were highly variable for both contemporary and historic birds. Although some historic birds exhibited extremely low δ15N values unmatched by contemporary birds (< 11.2‰), others had values as high as the highest fishery-associated contemporary birds. During the non-breeding season (sampled July-September), isotopic variability coalesced into a more narrow set of values for both contemporary and historic birds. Our results suggest that foraging strategies of Laysan albatross are a complex function of season, breeding status, and multi-annual breeding success, factors that likely affect the probability of association with fisheries.

Laysan and black-footed albatrosses, Phoebastria immutabilis and P. nigripes, exhibit both annual and biennial breeding frequencies, and annually replace flight feathers in patterns that can be described as large, small or medium in extent. Large molts are temporally incompatible with successful breeding. Small molts are temporally compatible with the longest breeding seasons. Medium molts are compatible with shorter, but still successful breeding seasons. On average, large and small molts combined replace the same feathers with the same frequencies as two medium molts combined. Thus, large and small annual molt patterns combined provide a mechanism for \"transferring time from one year to another\" enabling extended breeding seasons every other year, and thus biennial breeding. Medium-sized molts are compatible with annual breeding. Among multiple albatross species, large-scale, annual molt patterns can shift in response to shifting breeding frequencies, but there may be a time lag in the response. A newly identified period of rapid fattening following molt termination and preceding colony arrival suggests albatrosses maintain low fat stores throughout active molt to reduce wing-loading, intensifying temporal trade-offs between flight feather molt and breeding.

Animal migration is one of the most fascinating of all behaviors, links ecosystems and has profound ecological consequences over very large scales. Ungulate migration are among the most imperiled ecological phenomena in the world. Substantial populations of migratory ungulates are found in Mongolia's Gobi-Steppe Ecosystem (GSE), which is the largest area of intact steppe in the world and hense is of global importance.

To test the hypothesis that stable isotope ratios from marine organisms vary, the δ 15 N and δ 13 C values from fish and squid collected in Alaskan waters were measured across years (1997, 2000, and 2005), seasons, geographic locations, and different size/age classes, and between muscle tissue and whole animals. Temporal, geographic, and ontogenetic differences in stable isotope ratios ranged from 0.5–2.5‰ (δ 15 N) to 0.5–2.0‰ (δ 13 C). Twenty-one comparisons of stable isotope values between whole organisms and muscle tissue revealed only four small differences each for δ 15 N and δ 13 C, making costly and space prohibitive collection of whole animals unnecessary. The data from this study indicate that significant variations of stable isotope values from animals in marine systems necessitates collection of prey and predator tissues from the same time and place for best interpretation of stable isotope analysis in foraging ecology studies.

The northern fulmar Fulmarus glacialis is one of the most visible and widespread seabirds in the eastern Bering Sea and Aleutian Islands. However, relatively little is known about its abundance, trends, or the factors that shape its distribution. We used a long-term pelagic dataset to model changes in fulmar at-sea distribution and abundance since the mid-1970s. We used an ensemble model, based on a weighted average of generalized additive model (GAM), multivariate adaptive regression splines (MARS), and random forest models to estimate the pelagic distribution and density of fulmars in the waters of the Aleutian Archipelago and Bering Sea. The most important predictor variables were colony effect, sea surface temperature, distribution of fisheries, location, and primary productivity. We calculated a time series from the ratio of observed to predicted values and found that fulmar at-sea abundance declined from the 1970s to the 2000s at a rate of 0.83% (± 0.39% SE) per annum. Interpolating fulmar densities on a spatial grid through time, we found that the center of fulmar distribution in the Bering Sea has shifted north, coinciding with a northward shift in fish catches and a warming ocean. Our study shows that fisheries are an important, but not the only factor, shaping fulmar distribution and abundance trends in the eastern Bering Sea and Aleutian Islands.

There is great variation in discarding practice among fisheries in different parts of the world. Management systems result in some fisheries discarding mostly fish offal, much of which is macerated into small chunks, while other fisheries discard large (ca. 25 cm) whole fish. Scavenging seabirds consume high proportions of most categories of discarded fish and offal (typically 60 to 80% of discarded roundfish, 70 to 95% of discarded offal), but tend to avoid discarded benthic invertebrates and fish that are difficult to swallow, such as species with long spines or large flatfish. Amounts and composition of fishery discards and offal reaching benthic scavenging communities are clearly very strongly influenced by the intense but selective consumption by seabirds, and this alteration will depend strongly on details of the fishery management regulations and customs, such as whether or not waste is macerated. There is scope to adjust fisheries management practices to reduce the impact of offal and discards on scavenger communities.

Laysan Albatross (Phoebastria immutabilis) and the closely-related Black-footed Albatross (P. nigripes) replace 20%–90% of their 35–41 wing flight feathers every year. Large-scale molt patterns (patterns between rather than within molt series) account for 77% of the variation in the number of flight feathers replaced. We identified four molt series: series A—the five outer primaries; series B—the five inner primaries plus four outer secondaries; series C—the middle secondaries; and series D—the inner secondaries. A fifth molt series may lie between series C and D. Each year, series A and D initiate molt, but series B and C may or may not initiate molt. The result is four “annual molt patterns”: ABCD, ABD, ACD, and AD. Temporally overlapping waves of molt never occur within series A or B, but about one third of the time they occur within series C and D. Multiple, spatially defined waves of molt (replaced feathers separated by unreplaced feathers) never occur within series A, but occur about two thirds of the time within series B, C, and D. The inner primaries and outer secondaries constitute a single molt series, probably to equilibrate between series total feather length, and thus, total molt duration. Studies of foraging range and reproduction in albatrosses would benefit from the development of species-specific indices of molt duration and extent that are biologically as well as statistically defensible. The number of outer primary feathers replaced and the number of molt series that activate molt are two such indices for Laysan and Black-footed Albatrosses.

To test the hypothesis that stable isotope ratios from marine organisms vary, the [delta].sup.15N and [delta].sup.13C values from fish and squid collected in Alaskan waters were measured across years (1997, 2000, and 2005), seasons, geographic locations, and different size/age classes, and between muscle tissue and whole animals. Temporal, geographic, and ontogenetic differences in stable isotope ratios ranged from 0.5-2.5â° ([delta].sup.15N) to 0.5-2.0â° ([delta].sup.13C). Twenty-one comparisons of stable isotope values between whole organisms and muscle tissue revealed only four small differences each for [delta].sup.15N and [delta].sup.13C, making costly and space prohibitive collection of whole animals unnecessary. The data from this study indicate that significant variations of stable isotope values from animals in marine systems necessitates collection of prey and predator tissues from the same time and place for best interpretation of stable isotope analysis in foraging ecology studies.

Laysan Albatross (Phoebastria immutabilis) and the closely-related Black-footed Albatross (P. nigripes) replace 20%–90% of their 35–41 wing flight feathers every year. Large-scale molt patterns (patterns between rather than within molt series) account for 77% of the variation in the number of flight feathers replaced. We identified four molt series: series A—the five outer primaries; series B—the five inner primaries plus four outer secondaries; series C—the middle secondaries; and series D—the inner secondaries. A fifth molt series may lie between series C and D. Each year, series A and D initiate molt, but series B and C may or may not initiate molt. The result is four “annual molt patterns”: ABCD, ABD, ACD, and AD. Temporally overlapping waves of molt never occur within series A or B, but about one third of the time they occur within series C and D. Multiple, spatially defined waves of molt (replaced feathers separated by unreplaced feathers) never occur within series A, but occur about two thirds of the time within series B, C, and D. The inner primaries and outer secondaries constitute a single molt series, probably to equilibrate between series total feather length, and thus, total molt duration. Studies of foraging range and reproduction in albatrosses would benefit from the development of species-specific indices of molt duration and extent that are biologically as well as statistically defensible. The number of outer primary feathers replaced and the number of molt series that activate molt are two such indices for Laysan and Black-footed Albatrosses.

Laysan and black-footed albatrosses, Phoebastria immutabilis and P. nigripes, exhibit both annual and biennial breeding frequencies, and annually replace flight feathers in patterns that can be described as large, small or medium in extent. Large molts are temporally incompatible with successful breeding. Small molts are temporally compatible with the longest breeding seasons. Medium molts are compatible with shorter, but still successful breeding seasons. On average, large and small molts combined replace the same feathers with the same frequencies as two medium molts combined. Thus, large and small annual molt patterns combined provide a mechanism for \"transferring time from one year to another\" enabling extended breeding seasons every other year, and thus biennial breeding. Medium-sized molts are compatible with annual breeding. Among multiple albatross species, large-scale, annual molt patterns can shift in response to shifting breeding frequencies, but there may be a time lag in the response. A newly identified period of rapid fattening following molt termination and preceding colony arrival suggests albatrosses maintain low fat stores throughout active molt to reduce wing-loading, intensifying temporal trade-offs between flight feather molt and breeding.