The natural world likes to teach us about the complexity of interaction touch one strand in the web of life and its hard to know what else will get tugged; remove one butterfly and who knows what happens to the weather in New York. It also likes to remind us that often we can be most helpful by allowing these natural interactions to happen without our interference.
Mezquida et al. (2006) consider Sage-grouse and Indirect Interactions: Potential Implications of Coyote Control on Sage-grouse Populations. Not surprisingly, they present evidence that coyotes may help maintain healthy sage-grouse communities. As top-level predators (now that wolves are missing), coyotes help keep the mid-level predators (mesopredators) in check. This is important because mesopredators like foxes, badgers, and ravens are often implicated in chick and egg mortality, while coyotes show little interest in preying on grouse.
Coyotes also keep jackrabbit numbers down, which helps lower the abundance of other, more effective sage-grouse predators like golden eagles: with more rabbits to eat, eagles have higher reproductive rates, and end up taking more grouse as well. Jackrabbits also can compete with sage-grouse directly for forage, so coyotes can end up conserving vegetation for grouse.
But this isnt the story thats told at many of the sage-grouse stakeholder meetings. Instead, many call for more coyote control folks recall that when there was lots of coyote poisoning going on, there were more sage-grouse. This paper makes a good point that theres some truth to this, but probably because the mesopredators were also eating the poisoned baits - thats what most likely led to decreased grouse predation.
When the Colorado Division of Wildlife unveiled their Population Viability Analysis for greater sage-grouse last year, the only factor included in the model that could increase sage-grouse numbers was labeled predator control. They explained that this really should be interpreted as increased reproductive output or increased nest success, but this choice of language was very unfortunate and will perpetuate the myth that sage-grouse will benefit from coyote killing.
Mezquida et al. (2006) frequently cite a report by Rick Danvir with the Deseret Land and Livestock Ranch in northeastern Utah. This ranch, owned by the Mormon Church, has demonstrated that many wildlife-friendly practices are compatible with commercial production. They may even invite black-footed ferrets to their property some day. Mezquida et al. (2006) wrote:
Danvir (2002) provides a possible example for positive indirect effects of coyotes on sage-grouse. He found a nearly 500% increase in sage-grouse lek counts following cessation of coyote control and occupation of almost all habitat on the study area by coyote pairs. (p. 754)
The authors clarify that habitat manipulations also were conducted in the area and may be responsible for the sage-grouse gains, but this brings up an interesting possibility maybe coyote restoration should be considered a valid sage-grouse habitat improvement.
Coyote killing may seem like something out of the old West, but its still going on. This paper cites stats showing that between 1998 and 2004 an average of 33,278 coyotes were killed annually by Wildlife Services (a federal agency) alone in Colorado, Idaho, Montana, Nevada, Utah, and Wyoming.
Mezquida et al. (2006) conclude:
Healthy coyote populations and the elimination of coyote control measures, however, might greatly enhance the long-term prospects for sage-grouse populations. (p. 755)
Ill howl to that!
