Wolf and Moose Ratios in Alaska

Dr. Vic Van Ballenberghe / Wildlife Biologist / Alaska / January 1, 2004

Wolf control (the first round of it) in 20A went from 1976 to 1983 but most of it was 1976 to 1980. Moose went from 2800 in 1975 to 11,000 by 1992. Moose numbers since then have fluctuated around 10,000. Now, moose body condition (fat reserves) has declined to quite low levels and reproduction (twinning rate) has declined. Browsing intensity is high (heavy use of forage plants). ADFG proposed issuing hunting permits to shoot some calves in an effort to control the moose population and the Game Board approved. Despite this, hunting has not reduced moose numbers significantly. The general view is that forest fires in recent years improved moose habitat in portions of the area but that the moose population is likely to decline from overuse of the habitat and a "crash" could occur during a deep snow winter.


McGrath--The numbers get a little confusing. The 2001 moose census indicated 3655 moose. There has been confusion over the size of the area--ADFG now says 8500 sq.mi. (previously it was between 7000-8000). Extrapolating the density (0.43 moose/sq.mi.) to these different areas has confounded the actual number.

3000-3500 moose was the population objective set by a planning team and endorsed by ADFG and the Game Board as sufficient to meet the harvest demand (130-150 moose). I would avoid the term "healthy" moose population.

There were moose censuses in 1996 (1900 moose), 1999 (1400 moose), and 2000 (869 moose). All of these applied to only 5200 sq.mi. but were used for planning purposes. Attached is a document that attempts to equate these (by extrapolation) to the 2001 census applied to 8500 sq.mi.

The best interpretation of the censuses (I think) is that the 1996 and 2000 censuses were late winter counts and therefore not comparable to 2000 and 2001 (done in autumn). The 2000 census was done with poor snow conditions and underestimated true numbers. The only thing we can conclude is that we really don't know what was happening prior to 2001 but the 2000 census grossly underestimated the actual number of moose present.

I also think the bull:cow ratios are a little misleading. The 6:100 number came from one small area but does indicate that hunting supressed the number of bulls near the river (where most of the hunting occurs). In less accessible areas the ratio is higher (up to 37:100) because hunting doesn't remove many bulls. Again, I would avoid the term "healthy" ratios.