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Terrestrial Mammal Ecology Research Active

By Alaska Science Center July 13, 2017

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: 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 

Three caribou from the Porcupine Herd standing on the tundra
Sources/Usage: Public Domain.
Three caribou standing in the tundra.  These caribou are part of the Porcupine caribou herd.(Credit: Andrew Ramey, USGS. Public domain.)

 

 

 

Below are multimedia items associated with this project.

Background of a misty boreal forest, overlaid with an image of smiling white woman with short brown hair wearing a parka link
Central Arctic Herd caribou next to pipeline, North Slope of Alaska
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caribou crossing a road within the Kuparuk oil field, Alaska
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Caribou with Calves during Summer in Northern Alaska
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Mother and young caribou on Yukon-Alaska border
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Image: Caribou
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Caribou walking in a line in the winter in Northern Alaska
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A single caribou in the winter in Northern Alaska
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Caribou grazing near the Dalton Highway in the northern part of Alaska.
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Caribou roaming the Arctic Coastal Plain
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Caribou in the Winter in Northern Alaska
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Caribou in the Winter in Northern Alaska
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Caribou in the Winter in Northern Alaska
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Image: Caribou Along Alaska's Coast
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Caribou crossing the Selawik River, Alaska
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Three caribou from the Porcupine Herd standing on the tundra
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Below are publications associated with this project.

Filter Total Items: 46

Survival and reproduction in Arctic caribou are associated with summer forage and insect harassment

Investigators have speculated that the climate-driven “greening of the Arctic” may benefit barren-ground caribou populations, but paradoxically many populations have declined in recent years. This pattern has raised concerns about the influence of summer habitat conditions on caribou demographic rates, and how populations may be impacted in the future. The short Arctic summer provides caribou with
Authors
Heather E. Johnson, Beth Lenart, Dave Gustine, Layne G. Adams, Perry Barboza
By
Ecosystems Mission Area, Alaska Science Center

Dynamic selection for forage quality and quantity in response to phenology and insects in an Arctic ungulate

Spatiotemporal variation in forage is a primary driver of ungulate behavior, yet little is known about the nutritional components they select, and how selection varies across the growing season with changes in forage quality and quantity. We addressed these uncertainties in barren-ground caribou (Rangifer tarandus), which experience their most important foraging opportunities during the short Arct
Authors
Heather E. Johnson, Trevor Golden, Layne G. Adams, David Gustine, Elizabeth A. Lenart, Perry Barboza
By
Ecosystems Mission Area, Alaska Science Center

Spring phenology drives range shifts in a migratory Arctic ungulate with key implications for the future

Annual variation in phenology can have profound effects on the behavior of animals. As climate change advances spring phenology in ecosystems around the globe, it is becoming increasingly important to understand how animals respond to variation in the timing of seasonal events and how their responses may shift in the future. We investigated the influence of spring phenology on the behavior of migr
Authors
John P. Severson, Heather E. Johnson, Stephen M. Arthur, William Leacock, Michael J. Suitor
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Novel insights into serodiagnosis and epidemiology of Erysipelothrix rhusiopathiae, a newly recognized pathogen in muskoxen (Ovibos moschatus)

Muskoxen are a key species of Arctic ecosystems and are important for food security and socio-economic well-being of many Indigenous communities in the Arctic and Subarctic. Between 2009 and 2014, the bacterium Erysipelothrix rhusiopathiae was isolated for the first time in this species in association with multiple mortality events in Canada and Alaska, raising questions regarding the spatiotempor
Authors
F. Mavrot, K. Orsel, W. Hutchins, Layne G. Adams, K. Beckmen, J. Blake, S. Checkley, T. Davison, J. Di Francesco, B. Elkin, L. Leclerc, A. Schneider, M. Tomaselli, S. Kutz
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Ecosystems Mission Area, Alaska Science Center

Caribou use of habitat near energy development in Arctic Alaska

Increasing demands for energy have generated interest in expanding oil and gas production on the North Slope of Alaska, raising questions about the resilience of barren-ground caribou populations to new development. Although the amount of habitat lost directly to energy development in the Arctic will likely be relatively small, there are significant concerns about habitat that may be indirectly im
Authors
Heather E. Johnson, Trevor Golden, Layne G. Adams, David Gustine, Elizabeth A. Lenart
By
Ecosystems Mission Area, Species Management Research Program, Alaska Science Center

Evaluation of maternal penning to improve calf survival in the Chisana Caribou Herd

Predation is a major limiting factor for most small sedentary caribou (Rangifer tarandus) populations, particularly those that are threatened or endangered across the southern extent of the species’ range. Thus, reducing predation impacts is often a management goal for improving the status of small caribou populations, and lethal predator removal is the primary approach that has been applied. Give
Authors
Layne G. Adams, Richard G. Farnell, Michelle P. Oakley, Thomas Jung, Lorne Larocque, Grant Lortie, Jamie McLelland, Mason Reid, Gretchen H. Roffler, Don Russell
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Ecosystems Mission Area, Alaska Science Center

NDVI exhibits mixed success in predicting spatiotemporal variation in caribou summer forage quality and quantity

The satellite‐derived Normalized Difference Vegetation Index (NDVI) is commonly used by researchers and managers to represent ungulate forage conditions in landscapes across the globe, despite limited information about how it compares to empirical measurements of forage quality and quantity. The application of NDVI as a forage metric is particularly appealing for studying migratory caribou (Rangif
Authors
Heather E. Johnson, David D. Gustine, Trevor S. Golden, Layne G. Adams, Lincoln S. Parrett, Elizabeth A. Lenart, Perry S. Barboza
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Ecosystems Mission Area, Alaska Science Center

Mineral constraints on arctic caribou (Rangifer tarandus): a spatial and phenological perspective

Arctic caribou (Rangifer tarandus) have the longest terrestrial migration of any ungulate but little is known about the spatial and seasonal variation of minerals in summer forages and the potential impacts of mineral nutrition on the foraging behavior and nutritional condition of arctic caribou. We investigated the phenology, availability, and mechanistic relationships of calcium, phosphorus, mag
Authors
K. W. Oster, P.S. Barboza, David D. Gustine, Kyle Joly, R. D. Shively
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Ecosystems Mission Area, Alaska Science Center

The nitrogen window for arctic herbivores: plant phenology and protein gain of migratory caribou (Rangifer tarandus)

Terrestrial plants are often limited by nitrogen (N) in arctic systems, but constraints of N supply on herbivores are typically considered secondary to those of energy. We tested the hypothesis that forage N is more limiting than energy for arctic caribou by collecting key forages (three species of graminoids, three species of woody browse, and one genus of forb) over three summers in the migrator
Authors
Perry S. Barboza, Lindsay L. Van Someren, David D. Gustine, M. Syndonia Bret-Harte
By
Ecosystems Mission Area, Alaska Science Center

Summer habitat selection by Dall’s sheep in Wrangell-St. Elias National Park and Preserve, Alaska

Sexual segregation occurs frequently in sexually dimorphic species, and it may be influenced by differential habitat requirements between sexes or by social or evolutionary mechanisms that maintain separation of sexes regardless of habitat selection. Understanding the degree of sex-specific habitat specialization is important for management of wildlife populations and the design of monitoring and
Authors
Gretchen H. Roffler, Layne G. Adams, Mark Hebblewhite
By
Ecosystems Mission Area, Alaska Science Center

Bacterial genomics reveal the complex epidemiology of an emerging pathogen in arctic and boreal ungulates

Northern ecosystems are currently experiencing unprecedented ecological change, largely driven by a rapidly changing climate. Pathogen range expansion, and emergence and altered patterns of infectious disease, are increasingly reported in wildlife at high latitudes. Understanding the causes and consequences of shifting pathogen diversity and host-pathogen interactions in these ecosystems is import
Authors
Taya L. Forde, Karin Orsel, Ruth N. Zadoks, Roman Biek, Layne G. Adams, Sylvia L. Checkley, Tracy Davison, Jeroen De Buck, Mathieu Dumond, Brett T. Elkin, Laura Finnegan, Bryan J. Macbeth, Cait Nelson, Amanda Niptanatiak, Shane Sather, Helen M. Schwantje, Frank van der Meer, Susan J. Kutz
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Ecosystems Mission Area, Alaska Science Center

Identification 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 assump
Authors
Gretchen H. Roffler, Michael K. Schwartz, Kristy L. Pilgrim, Sandra L. Talbot, George K. Sage, Layne G. Adams, Gordon Luikart
By
Ecosystems Mission Area, Alaska Science Center

On January 22, 2020, USGS Alaska Science Center Research Biologist Heather Johnson was interviewed by Joshua Rapp Learn, a science writer for The Wildlife Society. The interview focused on a published paper by Johnson and co-authors that assessed whether caribou in the Central Arctic Herd of northern Alaska reduced their use of habitat near energy development. Read the February 3 article here.

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Caribou Appear to Keep up with Warming Arctic

Despite recent changes to the growing season for plants in the Arctic, Alaska, caribou appear to have remained in sync with these changes over the...

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The Other 364 Days of the Year: The Real Lives of Wild Reindeer

Caribou, North America’s wild reindeer, have lives apart from their famous role on Christmas Eve. Reindeer, of course, is another common name for...
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Climate Change Could Alter Range of Caribou and May Impact Hunters' Access

Alaska — Due to climate change, some communities in rural Alaska and the Yukon Territory of Canada may face a future with fewer caribou according to...

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