I found this article just today that relates to this topic. Hoo boy.
"Following the advice of so-called experts, all cattle have been removed on nearly one million acres surrounding Circle Ranch. Populations of the native species, especially bighorn, that these measures were intended to help have
declined dramatically, since the removals and eradications began in earnest around 2008."
And let's ignore the fact that desert bighorn populations have increased in other areas without cattle such as the Desert National Wildlife Refuge. These sheep don't rely on cattle or other large grazers for their survival.
"In far-West Texas TPWD and BRI along with Texas Bighorn Society (TBS) insist that Desert Bighorn Sheep reintroductions must include these costly attacks on nature if the reintroductions are to succeed. This premise which is the subject of the paper and article below, is unsupported by science, contradicted by the living example of healthy ecosystems like the Serengeti, recent developments at Yellowstone National Park, and the experience of restorative ecological managers worldwide, including us at Circle Ranch."
Let me just say before I go on, I do agree with the author on the issue with native predators and agree that they'd be helpful in controlling invasive species if they learn how to catch them. Cougars, after all, do hunt aoudads. I do not agree that the Serengeti can be used to contradict what he's arguing against because all the species in that ecosystem have co-evolved for millions of years and are ecologically different enough to coexist. Besides, the Serengeti is a much more resource-abundant place than dry places of Texas are, which intensifies competition.
"“Competition” is a favorite buzzword of invasive species biology. The term has become embedded in wildlife thinking as part of what amounts to a body of religious beliefs. As used by the authors, “competition” includes harmless things like eating, drinking, or surviving in a hostile environment. This paper’s core assumption is that these natural behaviors of aoudads harm bighorn sheep. No evidence is offered for this assumption, which is presented as self-evident. “Competition” is not defined.
The authors say that defenders of aoudad claim they and bighorn occupy completely different ecological niches. This is not what I think.
Let us stipulate to the self-evident: Aoudad do well in our declining desert grasslands, and all herbivores eat plants and drink water. Why is that bad? If it is bad and if aoudad compete with bighorn, do bighorn sheep compete with native deer, pronghorn, elk, cattle, cougar, coyotes, foxes and the rest? What are the distinctions? What science justifies these assumptions?
Is biodiversity good or bad? Are multiple species, and multiple individual animals, complementary or competitive? All of these creatures eat the same plants some of the time, and the plants require the animal impact in order to be healthy. Every animal will drink free water when available. So where is the evidence that overlapping diets or water use is harmful in nature?"
Yes, biodiversity is very good because that means healthy ecosystems. what the author is not understanding is that in nature there is what's called the Competitive Exclusion Principle which states that no two species can have the exact same niche in the exact same place at the exact same time. The reason is that simply put, some animals are better at a niche than others. Take the cats and borophagine dogs, for example, research by paleontologists indicates that the arrival of more cat species into North America caused the extinction of the borophaginae or bone-crushing dogs because they had the same niche and cats were simply better at it. On the African Plains, the herbivores actually "separate" the grass among themselves if you will. Some eat the tougher grasses while others eat the smaller, tender grasses. Interestingly, desert bighorns and mule deer didn't historically coexist with each other, but they do now because the habitat has gotten better for the deer, and pronghorns don't normally live in rocky areas, but in grassy areas instead, so they don't really compete with desert bighorns.
"Aoudad are a valuable buffer for bighorn predation."
Do you know what else provides a predation buffer for desert bighorns? Mule Deer. For those unfamiliar, lethal control has previously been used on cougars to boost desert bighorn populations. However, targeted removal is used since it's now known that the big cats prefer mule deer which are more abundant and only a few cougars become bighorn specialists. In other words, aoudads aren't actually needed to provide a predation buffer.
"Many professionals who suggest removing aoudad justify their advice by charging that aoudad drive bighorn and other animals off of water.
This is a bogus charge, based on Circle Ranch pictures of aoudad and sheep peacefully sharing water—and of other species using that same water or nearby water.We have reviewed 5,000 photos per month for 12-years at 13-camera points. All of this evidence has been offered to BRI and TPWD; thousands of photos are posted on this blog. Those who propose aoudad eradication because aoudad prevent other animals from drinking should share their proof."
Interesting because notice how in the picture presented, at the water source, that the aoudads are drinking first while the bighorns are waiting. Almost as if the bighorns know what will happen if they drink at the same time the aoudads do. Then again, this probably isn't even a water source but a food source. If that's the case, then they're the ones to talk about sharing proof in this case.
And that's basically what I've got for this article.
Interactions of Aoudad & Bighorn Sheep | Pitchstone Waters