This photograph shows three caribou escape the mosquitos on the mudflats of Kasegaluk Lagoon on the Chukchi Sea coast of Alaska. Coastal erosion along the Arctic coast is chronic, widespread and potentially accelerating, posing threats to infrastructure important for defense and energy purposes, natural shoreline habitats and nearby Native communities.
Terrestrial Mammal Ecology Research Active
Understanding the population dynamics, predator/prey relationships and habitat ecology of terrestrial mammals, such as caribou and muskoxen, is critical for the management of these species and their habitats in Alaska.
Return to Ecosystems >> Terrestrial Ecosystems
Research conducted by the USGS Alaska Science Center on terrestrial mammals is focused on informing Department of Interior management decisions across Alaska. Our work provides timely and highly relevant scientific information for management issues such as the response of caribou to a warming climate and human development, future possible changes in distribution and abundance, and the effects of changing habitats used for forage.
Population dynamics
Why do caribou populations fluctuate? Why do their migration patterns change year after year? How healthy is the herd? Working in collaboration with multiple partners in Alaska, the USGS is addressing these common questions for caribou populations in Alaska. Read more here: Improving calf survival of the Chisana Caribou Herd
Response of caribou to industrial infrastructure
Are Arctic caribou habituated to energy development on the North Slope? Do caribou use habitats near and within the oilfields in northern Alaska? Read more here:
- Effects of vehicle traffic on space use and road crossings of caribou in the Arctic
- Caribou use of habitat near energy development in Arctic Alaska
Forage and weather
Will caribou be impacted by changes in weather, insects and plant forages? Are their habitats changing?
Read more here: Resilience of caribou to climatic shifts in the Arctic
Below are multimedia items associated with this project.
This photograph shows three caribou escape the mosquitos on the mudflats of Kasegaluk Lagoon on the Chukchi Sea coast of Alaska. Coastal erosion along the Arctic coast is chronic, widespread and potentially accelerating, posing threats to infrastructure important for defense and energy purposes, natural shoreline habitats and nearby Native communities.
Caribou crossing the Selawik River, Alaska
Caribou crossing the Selawik River, Alaska
Three caribou standing in the tundra. These caribou are part of the Porcupine caribou herd.
Three caribou standing in the tundra. These caribou are part of the Porcupine caribou herd.
Below are publications associated with this project.
Identification of landscape features influencing gene flow: How useful are habitat selection models?
Range expansion of moose in arctic Alaska linked to warming and increased shrub habitat
Changing Arctic ecosystems: resilience of caribou to climatic shifts in the Arctic
Environmental and physiological influences to isotopic ratios of N and protein status in a montane ungulate in winter
Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic
Lack of sex-biased dispersal promotes fine-scale genetic structure in alpine ungulates
Range overlap and individual movements during breeding season influence genetic relationships of caribou herds in south-central Alaska
Population-level resource selection by sympatric brown and American black bears in Alaska
Are inland wolf-ungulate systems influenced by marine subsidies of Pacific salmon?
Stochastic and compensatory effects limit persistence of variation in body mass of young caribou
Ranking Alaska moose nutrition: Signals to begin liberal antlerless harvests
Evaluation of aerial survey methods for Dall's sheep
- Overview
Understanding the population dynamics, predator/prey relationships and habitat ecology of terrestrial mammals, such as caribou and muskoxen, is critical for the management of these species and their habitats in Alaska.
Return to Ecosystems >> Terrestrial Ecosystems
Research conducted by the USGS Alaska Science Center on terrestrial mammals is focused on informing Department of Interior management decisions across Alaska. Our work provides timely and highly relevant scientific information for management issues such as the response of caribou to a warming climate and human development, future possible changes in distribution and abundance, and the effects of changing habitats used for forage.
Population dynamics
Why do caribou populations fluctuate? Why do their migration patterns change year after year? How healthy is the herd? Working in collaboration with multiple partners in Alaska, the USGS is addressing these common questions for caribou populations in Alaska. Read more here: Improving calf survival of the Chisana Caribou Herd
Response of caribou to industrial infrastructure
Are Arctic caribou habituated to energy development on the North Slope? Do caribou use habitats near and within the oilfields in northern Alaska? Read more here:
- Effects of vehicle traffic on space use and road crossings of caribou in the Arctic
- Caribou use of habitat near energy development in Arctic Alaska
Forage and weather
Will caribou be impacted by changes in weather, insects and plant forages? Are their habitats changing?
Read more here: Resilience of caribou to climatic shifts in the Arctic - Multimedia
Below are multimedia items associated with this project.
Filter Total Items: 24Caribou Along Alaska's CoastThis photograph shows three caribou escape the mosquitos on the mudflats of Kasegaluk Lagoon on the Chukchi Sea coast of Alaska. Coastal erosion along the Arctic coast is chronic, widespread and potentially accelerating, posing threats to infrastructure important for defense and energy purposes, natural shoreline habitats and nearby Native communities.
This photograph shows three caribou escape the mosquitos on the mudflats of Kasegaluk Lagoon on the Chukchi Sea coast of Alaska. Coastal erosion along the Arctic coast is chronic, widespread and potentially accelerating, posing threats to infrastructure important for defense and energy purposes, natural shoreline habitats and nearby Native communities.
Caribou crossing the Selawik River, AlaskaCaribou crossing the Selawik River, Alaska
Caribou crossing the Selawik River, Alaska
Caribou of the Porcupine HerdThree caribou standing in the tundra. These caribou are part of the Porcupine caribou herd.
Three caribou standing in the tundra. These caribou are part of the Porcupine caribou herd.
- Publications
Below are publications associated with this project.
Filter Total Items: 47Identification of landscape features influencing gene flow: How useful are habitat selection models?
Understanding how dispersal patterns are influenced by landscape heterogeneity is critical for modeling species connectivity. Resource selection function (RSF) models are increasingly used in landscape genetics approaches. However, because the ecological factors that drive habitat selection may be different from those influencing dispersal and gene flow, it is important to consider explicit assumpAuthorsGretchen H. Roffler, Michael K. Schwartz, Kristy L. Pilgrim, Sandra L. Talbot, George K. Sage, Layne G. Adams, Gordon LuikartRange expansion of moose in arctic Alaska linked to warming and increased shrub habitat
Twentieth century warming has increased vegetation productivity and shrub cover across northern tundra and treeline regions, but effects on terrestrial wildlife have not been demonstrated on a comparable scale. During this period, Alaskan moose (Alces alces gigas) extended their range from the boreal forest into tundra riparian shrub habitat; similar extensions have been observed in Canada (A. a.AuthorsKen D. Tape, David D. Gustine, Roger W. Reuss, Layne G. Adams, Jason A. ClarkChanging Arctic ecosystems: resilience of caribou to climatic shifts in the Arctic
The U.S. Geological Survey (USGS) Changing Arctic Ecosystems (CAE) initiative strives to inform key resource management decisions for Arctic Alaska by providing scientific information and forecasts for current and future ecosystem response to a warming climate. Over the past 5 years, a focal area for the USGS CAE initiative has been the North Slope of Alaska. This region has experienced a warmingAuthorsDavid D. Gustine, Layne G. Adams, Mary E. Whalen, John M. PearceEnvironmental and physiological influences to isotopic ratios of N and protein status in a montane ungulate in winter
Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these sevAuthorsDavid D. Gustine, Perry S. Barboza, Layne G. Adams, Nathan B. WolfClimate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic
Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that deAuthorsDavid D. Gustine, Todd J. Brinkman, Michael A. Lindgren, Jennifer I. Schmidt, T. Scott Rupp, Layne G. AdamsLack of sex-biased dispersal promotes fine-scale genetic structure in alpine ungulates
Identifying patterns of fine-scale genetic structure in natural populations can advance understanding of critical ecological processes such as dispersal and gene flow across heterogeneous landscapes. Alpine ungulates generally exhibit high levels of genetic structure due to female philopatry and patchy configuration of mountain habitats. We assessed the spatial scale of genetic structure and the aAuthorsGretchen H. Roffler, Sandra L. Talbot, Gordon Luikart, George K. Sage, Kristy L. Pilgrim, Layne G. Adams, Michael K. SchwartzRange overlap and individual movements during breeding season influence genetic relationships of caribou herds in south-central Alaska
North American caribou (Rangifer tarandus) herds commonly exhibit little nuclear genetic differentiation among adjacent herds, although available evidence supports strong demographic separation, even for herds with seasonal range overlap. During 1997–2003, we studied the Mentasta and Nelchina caribou herds in south-central Alaska using radiotelemetry to determine individual movements and range oveAuthorsGretchen H. Roffler, Layne G. Adams, Sandra L. Talbot, George K. Sage, Bruce W. DalePopulation-level resource selection by sympatric brown and American black bears in Alaska
Distribution theory predicts that for two species living in sympatry, the subordinate species would be constrained from using the most suitable resources (e.g., habitat), resulting in its use of less suitable habitat and spatial segregation between species. We used negative binomial generalized linear mixed models with fixed effects to estimate seasonal population-level resource selection at two sAuthorsJerrold L. Belant, Brad Griffith, Yingte Zhang, Erich H. Follmann, Layne G. AdamsAre inland wolf-ungulate systems influenced by marine subsidies of Pacific salmon?
Wolves (Canis lupus) in North America are considered obligate predators of ungulates with other food resources playing little role in wolf population dynamics or wolf–prey relations. However, spawning Pacific salmon (Oncorhyncus spp.) are common throughout wolf range in northwestern North America and may provide a marine subsidy affecting inland wolf–ungulate food webs far from the coast. We conduAuthorsLayne G. Adams, Sean D. Farley, Craig A. Stricker, Dominic J. Demma, Gretchen H. Roffler, Dennis C. Miller, Robert O. RyeStochastic and compensatory effects limit persistence of variation in body mass of young caribou
Nutritional restriction during growth can have short- and long-term effects on fitness; however, animals inhabiting uncertain environments may exhibit adaptations to cope with variation in food availability. We examined changes in body mass in free-ranging female caribou (Rangifer tarandus) by measuring mass at birth and at 4, 11, and 16 months of age to evaluate the relative importance of seasonaAuthorsBruce W. Dale, Layne G. Adams, William B. Collins, Kyle Joly, Patrick Valkenburg, Robert TobeyRanking Alaska moose nutrition: Signals to begin liberal antlerless harvests
We focused on describing low nutritional status in an increasing moose (Alces alces gigas) population with reduced predation in Game Management Unit (GMU) 20A near Fairbanks, Alaska, USA. A skeptical public disallowed liberal antlerless harvests of this moose population until we provided convincing data on low nutritional status. We ranked nutritional status in 15 Alaska moose populations (in boreAuthorsRodney D. Boertje, Kalin A. Kellie, C. Tom Seaton, Mark A. Keech, Donald D. Young, Bruce W. Dale, Layne G. Adams, Andrew R. AdermanEvaluation of aerial survey methods for Dall's sheep
Most Dall's sheep (Ovis dalli dalli) population-monitoring efforts use intensive aerial surveys with no attempt to estimate variance or adjust for potential sightability bias. We used radiocollared sheep to assess factors that could affect sightability of Dall's sheep in standard fixed-wing and helicopter surveys and to evaluate feasibility of methods that might account for sightability bias. WorkAuthorsMark S. Udevitz, Brad S. Shults, Layne G. Adams, Christopher Kleckner - News