A5004256460- Avian ecology and behavior
- Wildlife Ecology and Conservation
- Species Distribution and Climate Change
- Fire effects on ecosystems
- Animal Behavior and Reproduction
- Animal Ecology and Behavior Studies
- Marine animal studies overview
- Ecology and Vegetation Dynamics Studies
- Rangeland and Wildlife Management
- Climate change and permafrost
- Wildlife-Road Interactions and Conservation
- Isotope Analysis in Ecology
- Cryospheric studies and observations
- Entomological Studies and Ecology
- Climate variability and models
- Atmospheric aerosols and clouds
- Plant and animal studies
- Arctic and Antarctic ice dynamics
- melanin and skin pigmentation
- Genetic diversity and population structure
- Bird parasitology and diseases
- Ship Hydrodynamics and Maneuverability
- Aquatic Invertebrate Ecology and Behavior
- Environmental DNA in Biodiversity Studies
- Fish Ecology and Management Studies
Alaska Department of Fish and Game
2016-2025
University of Alaska Fairbanks
2006-2021
Boise State University
2003
University of Wisconsin–Stevens Point
2000
Ecological “big data” Human activities are rapidly altering the natural world. Nowhere is this more evident, perhaps, than in Arctic, yet region remains one of most remote and difficult to study. Researchers have increasingly relied on animal tracking data these regions understand individual species' responses, but if we want larger-scale change, need integrate our understanding across species. Davidson et al. introduce an open-source archive that currently hosts 15 million location points...
Lead poisoning occurs worldwide in populations of predatory birds, but exposure rates and population impacts are known only from regional studies. We evaluated the lead 1210 bald golden eagles 38 US states across North America, including 620 live eagles. detected unexpectedly high frequencies eagles, both chronic (46 to 47% as measured bone) acute (27 33% 7 35% liver, blood, feathers). Frequency was influenced by age and, for region season. Continent-wide demographic modeling suggests that...
ABSTRACT Arctic habitats are changing rapidly and altering trophic webs ecosystem functioning. Understanding how species' abundances distributions differ among is important in predicting future species shifts trophic‐web consequences. We aimed to determine the habitat–abundance relationships for three small herbivores on Seward Peninsula of Alaska, USA by fitting data from 983 point counts (collected during 2019, 2021, 2022) with N‐mixture models that account imperfect detection. These...
Climate and landscape change are expected to affect species' distributions interactions, with potentially harmful consequences for specialist predators. Availability of optimal prey can reproductive success in raptors, especially the Arctic, where dramatic differences availability occur both within between years. However, behavioral responses dietary specialist, resident predators such as Gyrfalcons (Falco rusticolus) changes remain poorly understood. To improve understanding how...
We conducted repeated aerial surveys for breeding cliff-nesting raptors on the Yukon Delta National Wildlife Refuge (YDNWR) in western Alaska to estimate detection probabilities of Gyrfalcons (Falco rusticolus), Golden Eagles (Aquila chrysaetos), Rough-legged Hawks (Buteo lagopus), and also Common Ravens (Corvus corax). Using program PRESENCE, we modeled histories each species based single occupancy modeling. used different observers during four helicopter replicate Kilbuck Mountains five...
We used feathers from adult Gyrfalcons (Falco rusticolus) molted in breeding territories and blood samples nestlings to document nest-site fidelity dispersal of adults juveniles at three areas 100– 350 km apart Yukon Delta National Wildlife Refuge, Alaska, 2003–2007. genotypes seven polymorphic microsatellite loci that provided a mean probability identity 0.91 × 10-5. Breeding were highly faithful study area territory; we documented no dispersals birds among only one between territories. But...
For migrating animals, realized migration routes and timing emerge from hundreds or thousands of movement decisions made along routes. Local weather conditions continually influence these decisions, even relatively small changes in en route may cumulatively result major shifts patterns. Here, we analysed satellite tracking data to score a discrete navigation decision by large migratory bird as it navigated high-latitude, 5000 m elevation mountain range understand how those navigational...
Long distance migration can increase lifetime fitness, but be costly, incurring increased energetic expenses and higher mortality risks. Stopover other en route behaviors allow animals to rest replenish energy stores avoid or mitigate hazards during migration. Some animals, such as soaring birds, subsidize the costs of by extracting from flowing air. However, it is unclear how these sources affect interact with behavioral processes stopover in long-distance migrants. To understand effects...
Abstract The North American Breeding Bird Survey, Christmas Count, and regional national conservation assessments provide convincing evidence that the short‐eared owl ( Asio flammeus ) is experiencing a range‐wide, long‐term decline in abundance America. However, species has received little or research attention. vulnerable to because it relies heavily on large, intact grasslands specialized diet of unpredictable small mammal prey. species' nomadic movements compound these vulnerabilities by...
Human modification of landscapes includes extensive addition linear features, such as roads and transmission lines. These can alter animal movement space use affect the intensity interactions among species, including predation competition. Effects features on have seen relatively little research in avian systems, despite ample evidence their effects mammalian systems that some types both lines, are substantial sources mortality. Here, we used satellite telemetry combined with step selection...
Abstract Bayesian stable isotope mixing models (BSIMMs) for δ 13 C and 15 N can be a useful tool to reconstruct diets, characterize trophic relationships, assess spatiotemporal variation in food webs. However, use of this approach typically requires priori knowledge on the level enrichment occurring between diet tissue consumer being sampled (i.e. discrimination factor or TDF). Trophic factors derived from captive feeding studies are highly variable, it is challenging select appropriate TDF...
Abstract Rapidly advancing animal telemetry technologies paired with new statistical models can provide insight into the behaviour of otherwise unobservable free‐living animals. Changes in apparent from pairing often occur as animals undertake key life‐history activities, such reproduction. For many species that are secretive or occupy remote areas, these events difficult to detect conventional survey techniques, and consequently, vital rates estimate. We present a hierarchical modelling...
We used solar-powered time-lapse video photography to document nesting Gyrfalcon (Falco rusticolus) food habits in central West Greenland from May July 2000 and 2001. collected 2677.25 h of videotape three nests, representing 94, 87, 49% the nestling period at each nest. The recorded 921 deliveries 832 prey items. placed 95% items into categories. image quality was good but did not reveal enough detail identify most passerines species. found no evidence that Gyrfalcons were negatively...
We studied food habits of Gyrfalcons (Falco rusticolus) nesting in central west Greenland 2000 and 2001 using three sources data: time-lapse video (3 nests), prey remains (22 regurgitated pellets (19 nests). These provided different information describing the diet during period. relied heavily on Rock Ptarmigan (Lagopus mutus) arctic hares (Lepus arcticus). Combined, these species contributed 79–91% total diet, depending data used. Passerines were third most important group. Prey less common...
There are few published data on annual survival and no reports of lifetime reproduction for breeding Cooper's Hawks (Accipiter cooperii). Breeding males (n = 105) in central southeastern Wisconsin had an mortality rate 19%, or a 81% birds ≤10 years age. We did not detect significant differences rates between urban rural habitats, nor the earlier 13 later this study. Male produced from zero to 32 nestlings during their lifetimes. Body mass size appeared unrelated survivorship reproduction,...
Gyrfalcons (Falco rusticolus), Rock Ptarmigan (Lagopus muta), and Willow (L.lagopus) are quintessential Arctic species that closely linked within the ecosystem.They likely face similar challenges in of rapid changes to their climate.Gyrfalcons particular may be most challenged by climate change because relatively specialized ecological niche, small population size, K-selected life history strategy.Given this situation, we were interested predicting how distribution these under current...
There has been increasing concern for Golden Eagle (Aquila chrysaetos) populations in North America due to current and future projections of mortality risk habitat loss from anthropogenic sources. Identification high-use movement corridors bottlenecks the migratory portion eagle population western is an important first step help conservation management efforts reduce mortality. We used dynamic Brownian Bridge models estimate utilization distributions adult eagles migrating across identified...
The Short-eared Owl (Asio flammeus) is a widespread raptor whose abundance and distribution fluctuates in response to the varying amplitudes of its prey, which are predominately microtines. Previous efforts describe seasonal movements Owls have been hindered by few band recoveries species' cryptic irruptive behavior. We attached satellite transmitters adult at breeding areas western interior Alaska June 2009 July 2010, tracked their for up 19 mo. initiated long-distance southward from most...
La Masa Corporal de Hembras Accipiter cooperii No Esta Relacionada Con la Longevidad y Dispersion Reproductiva: Implicaciones Para El Estudio Reproductiva Capturamos, marcamos individualmente pesamos 271 hembras reproductoras segundo ano durante epoca cria en dos areas estudio principales Wisconsin el periodo comprendido entre 1980 2007. Luego recapturamos o volvimos a avistar algunas las aves utilizando prismaticos telescopios identificamos traves del color sus anillas. analizar relacion...
Some birds that attempt to nest in habitats such as conifer plantations may experience lower reproductive success and diminished fitness comparison conspecifics other habitats, rendering sinks or ecological traps. We did not detect significant differences between plantation non-plantation nests terms of clutch size, number bandable young per nest, for Cooper's Hawks (Accipiter cooperii) Wisconsin during 1980–1998. Pine contributed recruits subsequent breeding generations proportion their...
Comportamiento de Acicalamiento Halcones Falco rusticolus Adultos Marcados Con Transmisores Mochila Realizamos observaciones continuas o muestreos observacion instantanea para documentar el comportamiento acicalamiento dos hembras adultas reproductivas con transmisores satelitales 30 g y sus companeros libres en Refugio Delta Yukon Vida Silvestre, Alaska, (61.5°N, 164°W) a partir del 20 mayo hasta 6 julio 2005. Los fueron fijados las aves usando arneses tipo mochila hechos una cinta nylon 5...