Yellowstone National Park's Wolf Population Down More than 25 Percent

January 12, 2009

2008 was a tough year for Yellowstone's wolf population.

How healthy is Yellowstone National Park's wolf population? While wildlife biologists say the wolves overall are doing well and that the recovery program launched in 1995 has indeed succeeded, this past year was tough for the park's keystone predators.

Disease and infighting are being blamed for a drop of more than 25 percent in the numbers of wolves in Yellowstone. While the drop from 171 wolves in 2007 to 124 in 2008, or 27 percent, seems staggering, back in 2005 the numbers showed a slightly greater drop, from 171 wolves counted in 2004 to 118.

Plus, Yellowstone officials say last year's decline was the first drop in wolf numbers in the park in three years.

The greatest decline occurred on the northern range, the area with the greatest wolf population density. The wolf population there dropped 40 percent, from 94 to 56 wolves. The decline in the wolf population in the interior of the park was smaller. That population dipped from 77 to 68 animals, off 11 percent from the previous year.

The number of breeding pairs in the park also declined from 10 to six. This is the lowest number of breeding pairs recorded since 2000 when wolves first met the minimum population requirement for delisting.

Previous population declines in 1999 and 2005 were attributed to the impacts of disease, especially on wolf pups. This past year, distemper, mange, and wolves killing each other are the likely causes of the population decline.

Distemper is fairly common in wildlife and is believed to be the major contributor to the recent decline in the population of wolf pups in the park. The often fatal virus can be found in and readily transmitted between wolves and other animals such as coyotes, foxes, raccoons, and skunks.

Biologists will capture and sample wolves to confirm that distemper is indeed affecting wolves. In 1999 and 2005 distemper was found in both wolves and coyotes.

Mange is a parasitic infection of the skin. It can weaken the animal, making it susceptible to infections and other problems which can lead to death.

Finally, wolves often kill each other over competition for food or territory. Population density could contribute to an increase in wolf-on-wolf mortality.

Multi-year research projects are underway to help wildlife biologists better understand the impacts of disease and of animal social dynamics on wolf population changes.

A copy of National Parks Traveler's financial statements may be obtained by sending a stamped, self-addressed envelope to: National Parks Traveler, P.O. Box 980452, Park City, Utah 84098. National Parks Traveler was formed in the state of Utah for the purpose of informing and educating about national parks and protected areas.

Residents of the following states may obtain a copy of our financial and additional information as stated below:

  • Florida: A COPY OF THE OFFICIAL REGISTRATION AND FINANCIAL INFORMATION FOR NATIONAL PARKS TRAVELER, (REGISTRATION NO. CH 51659), MAY BE OBTAINED FROM THE DIVISION OF CONSUMER SERVICES BY CALLING 800-435-7352 OR VISITING THEIR WEBSITE. REGISTRATION DOES NOT IMPLY ENDORSEMENT, APPROVAL, OR RECOMMENDATION BY THE STATE.
  • Georgia: A full and fair description of the programs and financial statement summary of National Parks Traveler is available upon request at the office and phone number indicated above.
  • Maryland: Documents and information submitted under the Maryland Solicitations Act are also available, for the cost of postage and copies, from the Secretary of State, State House, Annapolis, MD 21401 (410-974-5534).
  • North Carolina: Financial information about this organization and a copy of its license are available from the State Solicitation Licensing Branch at 888-830-4989 or 919-807-2214. The license is not an endorsement by the State.
  • Pennsylvania: The official registration and financial information of National Parks Traveler may be obtained from the Pennsylvania Department of State by calling 800-732-0999. Registration does not imply endorsement.
  • Virginia: Financial statements are available from the Virginia Department of Agriculture and Consumer Services, 102 Governor Street, Richmond, Virginia 23219.
  • Washington: National Parks Traveler is registered with Washington State’s Charities Program as required by law and additional information is available by calling 800-332-4483 or visiting www.sos.wa.gov/charities, or on file at Charities Division, Office of the Secretary of State, State of Washington, Olympia, WA 98504.

INN Member

The easiest way to explore RV-friendly National Park campgrounds.

The Essential RVing Guide to the National Parks 

Here’s the definitive guide to National Park System campgrounds where RVers can park their rigs.

Our app is packed with RVing- specific details on more than 250 campgrounds in more than 70 national parks. 

You’ll also find stories about RVing in the parks, tips helpful if you’ve just recently become an RVer, and useful planning suggestions.

The Essential RVing Guide to the National Parks 

FREE for iPhones and Android phones.