Park wolf population declines by 27%-
This is no surprise because everyone who followed the Park wolves this year knew that with the high wolf pup mortality from some disease the population would decline.
I am skeptical that the Park wolf population will ever regain the high points reached twice in the last 5 years because of the decline in the elk numbers. It is possible that the restoration of the wolves resulting in a bit of an overshoot, and this might be true of the restored wolf population in Idaho as well. This is one reason why a big wolf hunt is premature.
Next year the wolf pup population could well recover as it has in the past, but the strife between the wolf packs will probably continue. That will keep wolf numbers down. It is also possible that this disease in not part of the natural regime. It might continue to reduce the wolf population until very low numbers are reached.
Bob Moen, who wrote the article below, uses 2007 data for the total number of wolves in Idaho, Montana, and Wyoming. However, it’s the 2008 figures, not yet available that will be interesting. Like the Park population we know that the overall wolf population did not grow by 20% as it has for a number of years. We don’t know that it grew at all, especially given what many see as excessive “wolf control” by Wildlife Services in Idaho and Montana.
Wolf numbers decline in Yellowstone in ’08. By Bob Moen. AP; and here is a similar story in the Jackson Hole News and Guide. By Cory Hatch.
Update. NPR story on the decline (audio). http://www.mtpr.net/program_info/2009-01-13-132
Comments
Word on the street is that the Idaho population is up 8-9% rather than the 20% often cited by the press.
I don’t think the reduction in the elk population is the primary factor for lower wolf numbers…I have seen evidence that the wolves prey on bison as well, though to a lesser degree. There are also deer and other smaller alternative prey for them to munch on. The disease outbreaks and low pup recruitment may be playing a greater role in driving numbers down.
If you don’t have pup recruitment, any wolf population will fall and pretty fast.
Wolves north of the Park find plenty of deer, and deer increasingly migrate onto the Park’s northern range in the summer now, but they don’t make up for elk. Bison are very tough for wolves to take and can only become a significant source of food in late winter and early spring. This fact is well confirmed by the 13 years of winter studies in the Park.
There is good wolf habitat north of the Park, but Montana FWP and mange have kept their numbers low. I think they are declining.
At any rate, wolves have to eat all year long. A late winter surplus of carrion and weak prey means lots of pups, but even without disease, lack of food later means not many pups will survive.
Statements made by Glenn Plumb make no reference to linking food availability to the decline in the wolf populations. In fact, he stated that the most likely causes are disease oubreaks or wolves killing other wolves due to inter-pack competition. Although, the observed decline may be also a combination of both factors
I don’t have any evidence except that there is more interpack strife now than when the elk population was higher.
If the wolves are somewhat stressed for food, that could indeed interact with disease.