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Full-Text Articles in Biology

Individual-Level Variation And Higher-Level Interpretations Of Space Use In Wide-Ranging Species: An Albatross Case Study Of Sampling Effects, Sarah Gutowsky, Marty Leonard, Melinda Conners, Scott A. Shaffer, Ian Jonsen Nov 2015

Individual-Level Variation And Higher-Level Interpretations Of Space Use In Wide-Ranging Species: An Albatross Case Study Of Sampling Effects, Sarah Gutowsky, Marty Leonard, Melinda Conners, Scott A. Shaffer, Ian Jonsen

Faculty Publications, Biological Sciences

Marine ecologists and managers need to know the spatial extent of at-sea areas most frequented by the groups of wildlife they study or manage. Defining group-specific ranges and distributions (i.e., space use at the level of species, population, age-class, etc.) can help to identify the source or severity of common or distinct threats among different at-risk groups. In biologging studies, this is accomplished by estimating the space use of a group based on a sample of tracked individuals. A major assumption of these studies is consistency in individual movements among members of a group. The implications of scaling up individual-level …


Wintering North Pacific Black-Legged Kittiwakes Balance Spatial Flexibility And Consistency, Rachael Orben, Rosana Paredes, Daniel Roby, David Irons, Scott A. Shaffer Oct 2015

Wintering North Pacific Black-Legged Kittiwakes Balance Spatial Flexibility And Consistency, Rachael Orben, Rosana Paredes, Daniel Roby, David Irons, Scott A. Shaffer

Faculty Publications, Biological Sciences

Background Marine environments are inherently dynamic, yet marine predators are often long-lived and employ strategies where consistency, individual specialization, routine migrations, and spatial memory are key components to their foraging and life-history strategies. Intrinsic determinates of animal movements are linked to physiological and life-history traits (e.g. sex, colony, experience), while extrinsic influences occur as the result of an animal’s interactions with either other animals or the environment (e.g. prey availability, weather, competition). Knowledge of the factors affecting animal movements is critical to understand energetic bottlenecks and population dynamics. Here, we attempt to understand the interaction of some of these factors …


Foraging Behavior Links Climate Variability And Reproduction In North Pacific Albatrosses, Lesley Thorne, Elliott Hazen, Steven Bograd, David Foley, Melinda Conners, Michelle Kappes, Hyemi Kim, Daniel Costa, Yann Tremblay, Scott A. Shaffer Oct 2015

Foraging Behavior Links Climate Variability And Reproduction In North Pacific Albatrosses, Lesley Thorne, Elliott Hazen, Steven Bograd, David Foley, Melinda Conners, Michelle Kappes, Hyemi Kim, Daniel Costa, Yann Tremblay, Scott A. Shaffer

Faculty Publications, Biological Sciences

Background: Climate-driven environmental change in the North Pacific has been well documented, with marked effects on the habitat and foraging behavior of marine predators. However, the mechanistic linkages connecting climate-driven changes in behavior to predator populations are not well understood. We evaluated the effects of climate-driven environmental variability on the reproductive success and foraging behavior of Laysan and Black-footed albatrosses breeding in the Northwest Hawaiian Islands during both brooding and incubating periods. We assessed foraging trip metrics and reproductive success using data collected from 2002–2012 and 1981–2012, respectively, relative to variability in the location of the Transition Zone Chlorophyll Front …


Reproductive Constraints Influence Habitat Accessibility, Segregation, And Preference Of Sympatric Albatross Species, Michelle Kappes, Scott Shaffer, Yann Tremblay, David Foley, Daniel Palacios, Steven Bograd, Daniel Costa Sep 2015

Reproductive Constraints Influence Habitat Accessibility, Segregation, And Preference Of Sympatric Albatross Species, Michelle Kappes, Scott Shaffer, Yann Tremblay, David Foley, Daniel Palacios, Steven Bograd, Daniel Costa

Faculty Publications, Biological Sciences

The spatiotemporal distribution of animals is dependent on a suite of factors, including the distribution of resources, interactions within and between species, physiological limitations, and requirements for reproduction, dispersal, or migration. During breeding, reproductive constraints play a major role in the distribution and behavior of central place foragers, such as pelagic seabirds. We examined the foraging behavior and marine habitat selection of Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses throughout their eight month breeding cycle at Tern Island, Northwest Hawaiian Islands to evaluate how variable constraints of breeding influenced habitat availability and foraging decisions. We used satellite tracking and …


Shadowed By Scale: Subtle Behavioral Niche Partitioning In Two Sympatric, Tropical Breeding Albatross Species, Melinda Conners, Elliott Hazen, Daniel Costa, Scott A. Shaffer Sep 2015

Shadowed By Scale: Subtle Behavioral Niche Partitioning In Two Sympatric, Tropical Breeding Albatross Species, Melinda Conners, Elliott Hazen, Daniel Costa, Scott A. Shaffer

Faculty Publications, Biological Sciences

Background To meet the minimum energetic requirements needed to support parents and their provisioned offspring, the timing of breeding in birds typically coincides with periods of high food abundance. Seasonality and synchrony of the reproductive cycle is especially important for marine species that breed in high latitudes with seasonal booms in ocean productivity. Laysan and black-footed albatrosses breeding in the northwestern Hawaiian Islands have a dual reliance on both seasonally productive waters of high latitudes and on nutrient-poor waters of low latitudes, because their foraging ranges contract during the short but critical brood-guard stage. Therefore, these species face an additional …