Friday, 16 April 2010

Things that have been on my mind a lot: Mesopreadators.

One thing I have been thinking a lot about is Mesopredators. Mesopredators are medium predators, such as racoons, coyotes, snakes, etc etc. A bear, wolf, puma etc would be a top predator, and not a mesopredator.

See, I was reading a paper recently about Pronghorn in Wyoming, where they had wolf-free and wolf-abundant sites. In their wolf-free sites, fawn (pronghorn have fawns, for some reason) survival was near 0 in some years, whereas in nearby wolf-abundant sites, fawn mortality was very low. They argue that the difference was in mesopredators, who differentially prey on fawns, and they try to show that coyote predation makes up the bulk of the wolf-free mortality. I know how practically difficult it is to make these calls, so I remain dubious of that. Still, it's hard to argue with that kind of finding in survival.

So, does interior AK have mesopreadators of consequence for our game? Coyotes are definitely mesopredators, and wolves generally do a good job keeping their populations surprised in most of the state (Coyotes are recent arrivals). I don't see much of a release when wolves are removed. Perhaps there are other factors limiting coyote release. Lynx can prey on reindeer calves, but do wolves keep lynx suppressed? I have a hard time envisioning this, because they don't have much niche overlap outside of that.

I'm still thinking about this, but I'm not sure mesopredators are a major factor in large game dynamics in non-SE Alaska.

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