In the February issue of BioScience, biologists describe the first-of-a-kind recording of caribou and ptarmigan migrations made with 14 automated cameras positioned in the northern foothills of the Brooks Range, Alaska. By analyzing some 40,000 images of the tundra landscape, Ken D. Tape of the University of Alaska and David D. Gustine of the US Geological Survey documented the northern spring migrations of both species. They estimated the number of individuals traveling, and made telling observations that shed light on caribou and ptarmigan behavior, without interfering with the animals by capturing and tagging them.
Tape and Gustine used cameras mounted on stakes, far enough away from a highway and from the Trans-Alaska Pipeline to reduce disturbance. Pairs of cameras, spread out over 65 miles, photographed upland sites and locations near rivers, which have different sorts of vegetation, every 15 minutes. Caribou were the easier subjects, and the researchers could estimate that they moved about 6 miles per day toward their calving sites later in the migration. They appeared to slow down to forage in areas of open ground and avoided river ice and open water. Ptarmigan, because they can fly quickly, were harder to count, and were seldom seen when snow covered all the vegetation. But they seemed to move at a similar speed to the caribou, on average. Other species, including bear, a wolf, ground squirrels, foxes, hawks, falcons, and owls, were seen occasionally, as well as a rare human.
Tape and Gustine maintain that automated cameras are a promising way for researchers to study other terrestrial migrations efficiently. The technology might thus make clearer the factors affecting migration of a wide range of species.
This Biologist's Toolbox article has been selected as the Editor's Choice and is published as public access. All articles in the February 2014 issue of BioScience are now published online as Advance Access at http://bioscience.oxfordjournals.org/content/early/recent.
BioScience is published monthly by Oxford Journals. Follow BioScience on Twitter @AIBS_BioScience.
Oxford Journals is a division of Oxford University Press. Oxford Journals publishes well over 300 academic and research journals covering a broad range of subject areas, two-thirds of which are published in collaboration with learned societies and other international organizations. The division has been publishing journals for more than a century, and as part of the world's oldest and largest university press, has more than 500 years of publishing expertise behind it. Follow Oxford Journals on Twitter @OxfordJournals.
The complete list of peer-reviewed articles in the February 2014 issue of BioScience is as follows:
Hydrologic Connectivity in the High-Elevation Tropics: Heterogeneous Responses to Land Change
Alexandra G. Ponette-González, Erika Marín-Spiotta, Kate A. Brauman, Kathleen A. Farley, Kathleen C. Weathers, and Kenneth R. Young
Historical Ecology and Invasion Biology: Long-Term Distribution Changes of Introduced Freshwater Species
Miguel Clavero and Daniel Villero
Insiders' Views of the Valley of Death: Behavioral and Institutional Perspectives
Amy K. Wolfe, David J. Bjornstad, Barry L. Shumpert, Stephanie A. Wang, W. Christopher Lenhardt, and Maria Fernanda Campa
How Students Think about Experimental Design: Novel Conceptions Revealed by in-Class Activities
Sara E. Brownell, Mary Pat Wenderoth, Roddy Theobald, Nnadozie Okoroafor, Mikhail Koval, Scott Freeman, Cristina L. Walcher-Chevillet, and Alison J. Crowe
Reconstructing Disturbances and Their Biogeochemical Consequences over Multiple Timescales
Kendra K. McLauchlan and colleagues
Capturing Migration Phenology of Terrestrial Wildlife Using Camera Traps
Ken D. Tape and David D. Gustine
Production Coordinator, BioScience
American Insitute of Biological Sciences (AIBS)
1900 Campus Commons Drive, Suite 200
Reston, VA 20191