Wolf density aids pronghorn fawn survival

I missed this important story earlier.

I wouldn’t say this is proven yet, but the hypothesis is based on the observed fact that wolves actively kill coyotes and reduce their numbers. It is also observed fact that wolves rarely bother with pronghorn fawns, but coyotes prey heavily on them.

Story in the Jackson Hole Planet. Wolf density aids pronghorn fawn survival. By Melanie Stein


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  1. chris Avatar
    chris

    There has been a similar study, perhaps by the same individual, in Yellowstone for several years. The pronghorn herd, especially in the Gardiner area has been declining and it was suspected that coyotes were doing a number on the fawns. As Ralph noted none of this is quite proven yet, but it does further indicate the changing dynamics resulting from wolf reintroduction. With wolves bringing coyotes back down to a more natural level, fawns of most ungulates may have higher chance of reaching adulthood. Once pronghorn and elk fawns are past their hiding phase, they can usually outrun a coyote.

  2. elkhunter Avatar
    elkhunter

    That might help the antelope fawns, but probably not the elk calves are high on the list for wolves. I can understand about the wolves lowering the coyote population, but when i mentioned that coyotes kill lots of proghorn fawns, everyone attacked me wanting to know how then they have survived for hundreds of years with coyotes eating them. I guess this kinda proves my point, but I dont see how the wolves are killing the coyotes that feed on antelope since their habitats are totally different, probably not very many wolves running out in the plains to my knowledge.

  3. kt Avatar
    kt

    The antelope population at Hart Mountain Refuge in Oregon has greatly rebounded – after ONE thing changed. Grazing was ended on the Refuge.

    3 or 4 years after grazing ended, the then-Refuge Manager sought to build his budget and ego) by instituting a coyote “control” program. Joy Belsky with ONDA stopped it. Guess what? Pronghorn numbers are doing very well. No need to kill coyotes – as time goes on without cows, things at Hart Mountain get better and better. AND so do sage grouse numbers.

    It’s my understanding that pronghorn young are born with great synchronicity (predator swamping). So, there is only a brief period when they are vulnerable to coyotes. Do they get preyed on less with stable coyote pairs, vs. APHIS-disrupted/heavily exploited populations??? Cold, wet weather right after they are born, and insufficient cover (poor habitat) can take a big toll.

  4. elkhunter Avatar
    elkhunter

    KT,
    Grazing is not the cause of everything negative in the animal world. Lots of elk calves are lost every year in Yellowstone is that because of grazing? Have you ever been out to proghorn country? There is hardly no cover, that is why antelope can run 55 miles an hour. Its nature’s way of allowing them to avoid predators. Of course young fawns its different. But I am sure if you cattle every where and they were eating everything to the ground then you might have a point. But I think drought and other natural conditions have more effect than cows, cause where I live in UT there are not thousands of cows every where I look. Which must be where you live because you talk about it alot.

  5. chris Avatar
    chris

    Pronghorn and wolves occupy the same habitat in Yellowstone. Pronghorn are found in spots all along the northern range including wolf viewing hotspots around Slough Creek and Lamar Valley. So at least in that part of the country there is a good chance of a similar coyote-wolf-pronghorn dynamic as in the Grand Teton study.

  6. kt Avatar
    kt

    Oh, I may have spent a day or two in pronghorn country …

    Here, we’ll let Steve Hermann tell the tale of Hart Mountain – a 19-page or so document

    http://www.rangenet.org/directory/hermans/HartMtn/HartMountain.pdf

    WARNING: The first image might offend your cow-coddling sensitivities.

    The land and the wildlife at Hart Mountain SHOW what happens when cattle grazing ends.

  7. Ralph Maughan Avatar

    Thanks KT. My spouse went to Hart Mountain 2 summers ago for a week of tearing down old cow pasture fences to make way for pronghorn.

    I think it was a real highlight in a decade of summer activities.

  8. elkhunter Avatar
    elkhunter

    Oh I am sure that cattle have a negative effect. Its just KT every post you say you refer to cattle. You cant blame everything on cows, thats all I am saying. Plus if you look at the chart of antelope populations in the mid-1990’s something happened that reduced populations, what was that?

  9. Joe S. Avatar

    I agree that coyotes kill a bunch of antelope fawns here in Idaho….Also that wolves kill a bunch of elk calves…
    Like elkhunter says antelope are plains animals not too many wolves running around the desert….
    coyotes need to be controlled just as wolves do….
    Kinda funny that the little dogs dont get as much love as the big ones on this site….personally i have no use for either…..

  10. Ralph Maughan Avatar

    Joe,

    The coyote was what replaced the wolf when it was extirpated, although the coyote is not a perfect replacement of the wolf.

    The fact that the coyote has spread to the entire continent of North America shows its biological fitness for our current environment. Your opinion on coyotes doesn’t matter to the natural course of events. Elimination of the wolf and the strong campaign against the coyote has made the coyote better and better at surviving. The coyote has won the day.

    Human “control” of coyotes does not reduce their population, except locally, and then only briefly unless 50% or more are killed each year. That is rarely done.

    If you care about pronghorn populations, as far as predators go, pronghorn fawns do much better with wolves around than with coyotes only, and there will always be some coyotes around.

  11. Joe S. Avatar

    Ralph i understand your arguement for wolves “saving antelope”…however weak it may be……In your estimation how much antelope territory would be suitable habitat for wolves>>>?

  12. Ralph Maughan Avatar

    Probably only in the higher elevation open country. The antelope range in the Great Basin is probably too low for wolves, although wolves may be able to live there in the mountains off the numerous mule deer in the summer and use the antelope range in the winter and early spring

    I just got back from a week in the backcountry of Nevada. It should not be discounted as minor wolf range. I noticed a lot of deer were still down in the valley bottoms in mid-March.

    If we want to really save antelope, we have to oppose the plans of the gas drillers, and the livestock overgrazers.

  13. chris Avatar
    chris

    Another impact livestock can have on pronghorn is the fencing the cows require. Pronghorn cannot jump and can therefore be deprived of access to forage and migration routes. Conservation minded ranchers leave space at the bottom of the fencing to allow pronghorn to crawl underneath.

  14. chris Avatar
    chris

    Let me correct myself, pronghorn probably can jump but the are extremely reluctant to jump fences. They prefer to go under rather than over.

  15. elkhunter Avatar
    elkhunter

    I dont really like hunting antelope. But I love hunting coyotes. So I will do my part to save the proghorn.

  16. Howard Avatar
    Howard

    Like any ecological relationship, I think the extent to which coyotes affect pronghorn varies from place to place as all other factors come into play. Generally speaking, the elimination of large predators like wolves leads to an unnatural abundance of meso-predators like coyotes. Coyotes, especially in packs, can and do kill ungulates in the West, but they are not particularly effective big game hunters and most of their diet (excluding carrion) consists of smaller animals. Interestingly, the critters most suppressed by high coyote densities are mainly other medium-sized and small carnivores…foxes and mustelids… because coyotes kill them outright as food and/or competitors, and as a result of competition for small prey items. Of all the Western ungulates, most (to my knowledge…if there is evidence to the contrary please let me know) don’t seem to suppressed by the smallish coyote EXCEPT the pronghorn. In days gone by, wolves would have kept coyotes at lower than present day levels across much of the pronghorn’s range (though the coyote was never RARE), which, coupled with predator swamping, probably resulted in proportionally fewer fawn losses to predators than today. Today, I imagine that coyote impacts on fawn survival vary with other factors…in regions where pronghorn habitat is optimal and the pronghorn population is high enough to facilitate predator swamping, pronghorn can probably maintain high populations and good recruitment even if total fawn loss to predators is higher than historical scenarios. In areas where coyote density is high but pronghorn density is low, however, coyotes can suppress pronghorn numbers to very low levels precisely because there are not enough pronghorn to effectively swamp fawn predators ( the classic predator pit situation). This is further compounded if limited habitat or habitat loss forces pronghorn to predictably congregate into smaller areas. In Yellowstone National Park, the pronghorn population is small and restricted to the lowest elevations at the extreme north of the Park. That is probably a place where coyotes were indeed affecting recruitment, and, assuming habitat is sufficient, the presence of wolves will probably aid fawn survival. Unlike coyotes, wolves do not seem to prey on pronghorn (of any age) in Yellowstone (I believe that in 11 years, there is evidence of 1 pronghorn kill by wolves inside YNP)… I think they’re just too fast and not common enough to interest wolves. Pronghorn probably evolved their astonishing speed in response to the North American cheetahs that last roamed the plains during the Pleistocene, and after their first few days of life, are by and large immune to all extant non-human predators . I think they’re a fantastic animal… uniquely North American too… and the only surviving species of the family Antilocapridae.

Author

Dr. Ralph Maughan is professor emeritus of political science at Idaho State University. He was a Western Watersheds Project Board Member off and on for many years, and was also its President for several years. For a long time he produced Ralph Maughan’s Wolf Report. He was a founder of the Greater Yellowstone Coalition. He and Jackie Johnson Maughan wrote three editions of “Hiking Idaho.” He also wrote “Beyond the Tetons” and “Backpacking Wyoming’s Teton and Washakie Wilderness.” He created and is the administrator of The Wildlife News.

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