The Much Maligned Coyote

Here in Nebraska, we’ve lost most of our largest predators.  Bears and wolves are gone (excepting rare long-distance wanderers).  Mountain lions are making a slow comeback in the northern and western parts of Nebraska, but the agricultural character and fragmented nature of our state makes it difficult to imagine a much stronger presence of large predators than we have right now.  That’s not a critique – it’s just reality.  It’s difficult to know what effect the absence of those predators has on our wildlife and natural landscapes, but based on what we know from research elsewhere, it’s surely significant.  Throughout the world, and across a wide range of habitat types, major predators stimulate complex cascades of impacts far beyond simply suppressing the populations of their favored prey species.  In fact, the diversity and abundance of many plant, invertebrate, and wildlife species have been shown to decline dramatically when dominant predators disappear.

Illustration by Kim Tri

Coyote illustration by Kim Tri, one of our Hubbard Fellows and, obviously, a talented artist.

Today, in the absence of wolves and bears, coyotes have stepped into the role of top mammalian predator across much of Nebraska.  It’s hard to know if they are as effective as their larger counterparts at maintaining ecosystem function, but there is strong scientific evidence for the strong and positive impacts coyotes have on a number of other grassland species.  Much of the research on this topic was published 15-20 years ago, but few people seem to be familiar with it.  In fact, rather than being celebrated for their importance, coyotes are widely reviled, and often shot on sight, by many (most?) rural citizens across much of prairie regions of North America.

There is much unfortunate irony in the vilification of coyotes.  One common coyote narrative is that coyotes are hard on nesting birds, especially game species like pheasants, quail, turkeys, grouse, and ducks.  In reality, coyotes feed mainly on rodents, and the major predators of birds and their nests tend to be smaller animals, including foxes, raccoons, and cats (especially feral house cats).  Coyotes are large and aggressive enough to intimidate or kill those “mesopredators”, keeping their numbers low and driving them into areas where coyotes spend the least time, such as wooded draws, farmsteads, and even surburbia.  In fact, numerous studies have documented detrimental impacts to bird populations ranging from songbirds to ducks and grouse when coyote numbers are suppressed and mesopredator populations swell.

One of the most dramatic studies of coyote impacts on the structure and function of ecological communities took place on 20,000 hectares of west Texas land back in the 1990’s.  Researchers halved the number of coyotes in one portion of the study area and left the population alone elsewhere.  Within a year of coyote control, the area with fewer coyotes experienced higher populations of bobcats, badgers, and gray foxes.  Perhaps as a result, 11 of the 12 rodent species in that area disappeared, leaving only a skyrocketing population of kangaroo rats.  Jackrabbits also tripled their numbers in the coyote control area, much to the chagrin of ranchers, since jackrabbits compete with livestock for forage.

Another great coyote illustration by Kim Tri.

Another great coyote illustration by Kim Tri.

Speaking of ranchers, many tend not to be coyote fans, in large part because coyotes are sometimes hard on livestock.  Sheep ranchers can suffer big losses to coyotes if they don’t actively protect sheep with dogs, overnight enclosures, and other strategies.  Cattle ranchers can also have trouble with coyotes killing livestock, especially just-born calves.  Coyotes are very good at killing young deer fawns – a great reason for prairie enthusiasts to be coyote fans, by the way – but some transfer that skill to calves as well.  While any self-respecting cow can protect her calf from coyotes under most circumstances, even the toughest mother is weakened enough by the process of giving birth that she is vulnerable to a quick sneak attack.

Unfortunately, the response to livestock losses is often the indiscriminate killing of whatever coyotes ranchers can find.  Research has shown that kind of “coyote control” to be largely ineffective, in part because it usually fails to kill the individuals actually causing problems.  For example, a fourteen year study showed that almost every sheep killed by coyotes was taken by the “alpha pair” in the pack’s social structure.  Those alpha animals are also the wiliest and most difficult to kill.  Furthermore, of course, in the unlikely event that coyote control efforts succeed at suppressing the population in an area, the results might not turn out in favor of the rancher.  Higher numbers of raccoons and foxes, not to mention jackrabbits, along with fewer ducks, grouse, and quail, might take the thrill out of the temporary victory.

Even if coyotes gain wider recognition for their positive effects on natural systems, however, the relationship between coyote and human is bound to be complicated.  As we continue to alter their habitat, coyotes will continue to adapt and survive as best they can.  At times, that will bring them into conflict with us.  It is understandable, for example, that a rancher needs to address livestock losses, and sometimes that could mean tracking down and killing the individual coyote(s) responsible.  However, that kind of careful, targeted response is much different (and more effective) than current broad, indiscriminate campaigns against an animal whose bad reputation is largely based on innuendo and misinformation.

Ideally, seeing coyote tracks on their property would be a positive experience for landowners.

Ideally, seeing coyote tracks on a property would be a positive experience for landowners.

Coyotes and other predators play critically important roles in grassland ecosystems.  It’s easy to understand how they directly suppress populations of their primary prey species.  However, as we continue to study predators, we find more and more of the kind of indirect impacts that ripple through ecological systems in ways that are difficult to predict.  While it seems unlikely that wolves and bears will ever return to prominence in Nebraska or most other prairie regions of North America, coyotes may be able to cover at least some of the ecological roles those larger predators once played.

But only if we let them.

 

Photo of the Week – November 5, 2015

As I was looking at some of my recent photos from our Niobrara Valley Preserve, I realized that I have a series of photos from approximately the same vantage point that illustrates the site’s recovery from the major wildfire back in 2012.  If you’ve followed this blog for several years, you’re probably aware that we have a significant timelapse project going on at the Niobrara Valley Preserve that is documenting that recovery as well.  Those images will provide a very comprehensive look at change over time, but those cameras weren’t installed until after the fire.  The three photos below are interesting because they represent shots taken before, immediately after the fire, and a few years later.

October 1, 2011

October 1, 2011

The above photo was taken in the fall before the big 2012 wildfire.  The big pine tree on the right is a good landmark to watch as you compare this photo to the next two.  The following photo was taken just a few days after the wildfire.

July 25, 2012

July 25, 2012

The last photo (below) was taken just a few weeks ago.  The grass and other vegetation has clearly recovered nicely from the fire.  That’s not really a surprise to any of us who are familiar with grassland fires.  Even a very hot summer fire in the midst of severe drought is not typically fatal to most prairie plants.  In fact, the drought was harder on prairie plants than the fire was, but even so, those plant species are well adapted to both.

TNC Niobrara Valley Preserve, Nebraska.

October 23, 2015

More interesting than the recovery of grasses and wildflowers is the recovery of woody plants.  The two small pine trees on the left side of the image look happy and healthy, despite the fact that young ponderosa pines tend to be vulnerable to fire.  If you look closely at the image taken immediately after the fire, you can see both of those trees.  The one on the right, especially, had the majority of its needles burned by the fire, but both appear to have come out of that stressful period just fine.  Why were those two trees able to survive (along with the big tree) here when just across the river, almost every single pine on the south-facing slope died?  Most likely, there are multiple reasons, including slope, fire intensity, and the fact that these trees were surrounded mostly by grasses instead of lots of other pine trees (and eastern red cedars).  The point of showing these photos isn’t to answer these kinds of questions as much as it is to stimulate them.

It’s also interesting to note that most of the oaks and other big deciduous trees seem to have survived.  That is the case across most of the Preserve, although many of the bur oak trees that were growing close to pine and eastern red cedar trees were top-killed by the fire and are now regrowing from the base.  A few oaks and other deciduous trees (especially cottonwoods) did die from the fire, but most didn’t.

I’m hoping to put together some timelapse sequences this winter that will help tell the story of recovery from multiple locations across the Preserve.  For the most part, those stories will show that the natural communities along the Niobrara River are well-adapted to major disturbances such as the drought and fire that occurred in 2012.  The big exception is the pine woodland that was nearly completely wiped out across big swaths of the landscape. The density of pine and cedar trees led to fire intensity that caused 100% mortality in many stands, and while those areas will recover, they will be grassland and/or shrubland for a very long time, and their long-range future as pine woodlands is far from assured.

Aside from those pine woodlands, however, the natural communities across the Preserve did what natural communities usually do in response to fire, drought, and other major events – they continued to thrive.