As predicted in December, wolf numbers in Yellowstone National Park were down 23 percent in 2009 compared to 2008.
According to figures released from the Yellowstone Wolf Project, the park’s wolf population is 96-98 wolves; 124 wolves were recorded in 2008. It is the fourth decline since wolf reintroduction began in 1995. A population high of 174 wolves was recorded in 2003.
Population declines in 1999, 2005 and 2008 were associated with the disease distemper. So far there is no evidence that distemper was the cause of the 2009 decline. Probable causes for the decline in 2009 were wolves killing each other, malnutrition and mange.
The greatest decline occurred on the northern range, the area with the greatest wolf density and where park visitors are drawn in hopes of seeing a wolf. Wolf numbers there dropped 29 percent, from 56 to 40 wolves.
The decline in the wolf population in the interior of the park was smaller. Those numbers dipped from 77 to 68 animals, off 11 percent from the previous year.
The number of breeding pairs in the park remained the same at six, the lowest number of breeding pairs recorded since 2000 when wolves first met the minimum population requirement for delisting. A breeding pair is defined as a male and female with two surviving pups. Poor pup survival, due primarily to disease, has kept that number low.
