|Re: coyote control on March 17, 2010
||Reply / Edit
The much-publicized decline in coyote numbers in (some areas of) Yellowstone was a straightforward case of direct competition and intraspecifc aggression.
The state of coyote ecology before 1995, like everything with Yellowstone, is an unusual scenario. The coyotes of the park had been without competition for ~ 50 years. Animals on the northern range had responded by running in groups (~packs) and generally dominating the landscape at their trophic level. The behaviour and abundance of coyotes was influenced by (a) protection from human persecution,( b) lack of natural competition and (c) a very productive landscape.
Then, accompanied by lots of parkies, politicos and cameras, the wolves bolted from their acclimating pens (well, they actually had to be pushed out). They immediately set about correcting this ecologically unique state of affairs: they shredded unwary or overconfident coyotes, including excavations of dens to kill entire litters of coyote pups.
A commonly used figure in the literature is that ‘coyotes declined 50%’. This is in reference to one well-studied area of the park, not park-wide, and without going in to personality-riddled detail, I can say that figure continues to be a source of great debate.
Putting aside quantitative rigor and high drama, there was indeed a decline in coyotes following wolf reintroduction - that much is obvious. Aside from chasing and killing adults and pups with abandon, wolves hit coyotes where it really hurt – resources. The resources (speaking mostly of ungulates) that coyotes were able to control in the absence of wolves were suddenly reduced. The wolves not only killed ‘em on sight, but they ate a lot of their food! It’s hard to see coyote fecundity maintained, much less increased, under that scenario. That is likely the key to effectively reducing (but note: still not eradicating) coyotes.
Notably, this is where we as humans have been unable to strike coyotes. We can’t deprive coyotes of a resource base because we <i> generate coyote resources wherever we go</i>. That is why they’ve expanded so much. Coyotes, much like white-tailed deer, are able to exploit the highly modified landscapes which characterize humanity. We pave the way: we remove competition, bring in yummy (and stupid) livestock species and pets, throw out garbage and create dumps.
So we arrive at the big differences between human hunting and natural competition:
1) competing predators kill each other relentlessly: there is no off-season, no quota, no rules of fair play. They pursue each other nonstop, day and night, 365 days a year, in places where no hunters would venture – places far from roads and in swamps and brush so thick it forces you to tunnel through on your hands and knees. We could try to seek them out across the landscape and attack them like that, but can you imagine the cost and effort? How many folks can sniff out coyote dens on the island and dig them up with a shovel?
2) coyotes thrive in the landscapes we create for ourselves, utilizing the stuff we bring with us and the waste we throw out. No natural predator modifies the world to make life easier for its enemies. Simply by being here, we create coyote habitat.