Path of the Pronghorn

WCS involvement in the West began nearly 100 years ago with a campaign to preserve the bison, and WCS conservation and research continues today in the quintessential wilderness of Greater Yellowstone.  One of the most intact mountain environments in the continental United States, Greater Yellowstone supports an unequaled diversity of large mammals.    This area is home to a yearly animal migration that has occurred since the last Ice Age.  WCS seeks to elucidate the impacts of human activities on this migration and to use research results to help inform local management.

The Human Aspect
The migration of pronghorn in and out of Grand Teton National Park, with movements up to 170 miles, is the longest terrestrial mammal migration between Argentina and Canada.  Maintaining corridors and understanding migration mechanics are critical components of ensuring the persistence of this unique ecological process and the large ungulate population it supports.

Threats
Long-distance migration is one of Earth's most stunning, yet imperiled, ecological processes.  Currently, the migration, and hence the viability, of pronghorn in Grand Teton National Park is jeopardized by large-scale energy development, increasing private land development, and imbalanced predator/prey relationships. 

WCS Activities
WCS is a wildlife research and conservation organization that seeks and uses science-based information to work collaboratively with a wide variety of public and private stakeholders.  The goal of this study is to develop and implement a strategy to conserve the longest remaining migration corridor in Greater Yellowstone, ensure the local survival of pronghorn antelope, and set a precedent for similar efforts elsewhere.   WCS biologists are studying the biological costs of disturbance from increased energy development on pronghorn wintering grounds, and obtaining fine-scale information about the different pathways utilized by these animals to move from summer grounds in Grand Teton National Park to wintering grounds in the Red Desert region south of Pinedale, Wyoming.  The retention of a migratory species in an accessible national park and the sensational nature of long-distance travel represent a phenomenon of immeasurable conservation value.

Important Next Steps

• Place radio-tracking collars on individual pronghorn to obtain fine-scale
  information on pronghorn migration travel routes and patterns.
• Document survival rates of pronghorn antelope fawns, including impacts of
  predators and winter survival.
• Collaborate with stakeholders to ensure that critical passes and constricted
  sections of the migration route remain open.
• Conduct behavioral studies to assess the energetic cost of increased disturbance
  on pronghorn antelope from expanding human activity as related to energy
  development.
• Provide information to resource management agencies, key private landowners,
  and local conservation organizations to facilitate stronger cooperation to
  protect this pronghorn population and remnant migratory pathway. 
  

Selected and representative publications


peer-reviewed journal publications
Berger, J. The Last  Mile:  How to Sustain Long Distance Migration
     in Mammals.  Conservation Biology   18(2):320-331.
Pyare, S., S. L. Cain, D. Moody, C. Schwartz, and J. Berger.  Grizzly
     bears in the Yellowstone Ecosystem; Loss and Re-colonization Rates
     during a Century of Change.  Animal Conservation  7:1-7.
Berger, J. 2003.  Is it Acceptable to Let a Species go Extinct in a
     National Park?  Conservation Biology 17: 1451-1454. 
Berger, J.  2003.  Through the Eyes of Prey: How the Extinction and
     Conservation of North America’s Large Carnivores Alter Prey Systems
     and Biodiversity.  Pp 133-156, In Animal Behavior and Wildlife Conservation
     (eds. M. Festa-Bianchet and M. Apollonio). Island Press, Covello, CA).
Pyare, S. and J. Berger.  2003.  Beyond demography and delisting: ecological
     recovery for Yellowstone’s Grizzly Bears and Wolves.  Biological Conservation
     113:63-73.
Berger, J. 2002.  Wolves, Landscapes, and the Ecological Recovery
     of Yellowstone.  Wild Earth12:32-37.
Berger, J. and K. Berger. 2001.  Endangered Species and the decline of
     America's Western Legacy?  Bioscience  51:951-953.
Berger, J., J. E. Swenson, and I. Per-Illson.  2001.  Re-colonizing Carnivores
     and Naive Prey; Conservation Lessons from Pleistocene Extinctions. 
     Science 291:1036-1039.
Berger, J. P. B. Stacey, M. L. Johnson, and L. Bellis.  2001. A Mammalian
     Predator-Prey Imbalance: Grizzly Bear and Wolf Extinction Affects Avian
     Neotropical Migrants.  Ecological Applications 11:947-960.
Berger, J.  1999.  On Intervention and the Persistence of Small Populations
     of Bighorn Sheep.  Conservation Biology 13:432-435
Berger, J.  1991.  Greater Yellowstone's Native Ungulates: Myths and
     Reality.  Conservation Biology  5:353-363.

Books
Cunningham, C. and J. Berger.  1997.  Horn of Darkness: Rhinos on the Edge.
     Oxford University Press.
Berger, J. and C. Cunningham.  1994.  Bison: Mating and Conservation
     in Small  Populations. Columbia University Press. 
Berger J.  1986.  Wild Horses of the Great Basin: Social Competition
     and Population Size.   University of Chicago Press, Chicago.