Science Versus Politics

A Case Study featuring Wild Horses, Ravens and Greater Sage-grouse.

Centrocercus Urophasianus or Sage-grouse, a Nevada protected game bird - image - CC BY-NC-SA 4.0 Bob Tregilus Photography

Opinion

Recently, a U.S. Geological Survey study (USGS) by Peter Coates, Ph.D., et.al looked at the relationship between wild horses and numbers of male greater sage-grouse present at sage-grouse breeding grounds (leks) in Nevada and California.    

Researchers sought lek locations that overlapped with Herd Management Areas, defined by the Bureau of Land Management (BLM) as locations where wild horse and burro populations are legally entitled to live on public lands.  

Horse density numbers in proximity to leks were estimated using BLM population data. Numbers of male greater sage-grouse attendees at the leks were directly observed.

The study findings suggest that, above Appropriate Management Level (AML) (A rather arbitrary number set by BLM. See below.), increased wild horse numbers were associated with reduced lek attendance by male greater sage-grouse. The assumption is that higher grouse numbers on leks equate with better population dynamics for the birds. Lower numbers mean the opposite.

Although there was domestic livestock grazing in the vicinity of leks, the authors … oddly (and perhaps fatally) … did not account for its presence or impact on lek attendance by greater sage-grouse males. The lack of available and reliable livestock data was an impediment.  

(Could they have simply counted ‘cow pies’ along a transect at each site?)

Rather, the authors appear to have assumed that livestock numbers and impacts around all leks would be similar because ‘cows do what cows do’ in grazing allotments, thereby allowing researchers to focus solely on wild horses as the variable of interest. (Burro impacts were also disregarded by the study authors.)

(Appropriate Management Level (AML) and Animal Unit Month (AUM) – BLM terms for who gets the space and forage on public lands – are, arguably, based more on value judgments and user preference, i.e., political decisions, than on science. Wild horses get something like 12% of all AUMs on public lands and about that amount of space compared to domestic livestock. Domestic livestock – mostly cattle – using public lands in Nevada outnumber wild horses by 10:1, by 50:1 across the West.)

The lead author/researcher of this study, Peter Coates, Ph.D. is a UNR graduate having received a Master of Biology degree in Reno prior to his Ph.D. He conducted greater sage-grouse/raven research in Nevada early in his career focusing on raven depredation (removing eggs) on greater sage-grouse nests. 

So, what to make of this?

First of all, wild horses do not make the greater sage-grouse ‘Top 10’ threat list, not even close. (Neither do ravens, by the way.)  

This study does not address the largest, most important issues facing greater sage-grouse recovery.  Poor quality sagebrush communities around the West (created in large part by a long history of domestic livestock grazing in the West) top the list.

Second, any study targeting wild horses – even a scientific study – no matter how dense the statistical analysis, how complete the modeling data, lacks credibility if it disregards domestic livestock impacts completely. Wild horses and domestic livestock are ‘joined at the hip’ on public lands in the West.

Anybody with a modicum of familiarity with Nevada’s public lands knows that domestic livestock grazing has had profound impacts on the landscape for more than a century.

(As a small example, Dr. Coate’s narrative suggests wild horses contribute to cheatgrass infestation without mentioning that domestic livestock grazing has made a legendary contribution to the same problem.)

Third, no matter how stratospheric the scientific integrity or intentions of the study authors, no matter the careful data analysis and elegant modeling, ‘fingering’ wild horses as contributors to greater sage-grouse decline (despite their relative lack of importance) likely means this work will serve more of a ‘political’ purpose than a scientific contribution to our understanding of greater sage-grouse decline.

How so? A political purpose?

It’s known as ‘scapegoating’.

Case in point:

Management agencies (probably of all persuasions) look for ways to implement management strategies they favor but lack justification. The Nevada Board of Wildlife Commissioners (NBWC) is no exception.

In decades past, sportsmen begged and pleaded with NBWC for a raven-hunting season. Such requests went unrequited because ravens are a federally protected species (see below) and are not available to be hunted in the traditional way. 

Ravens have long been viewed with antipathy by sportsmen, wildlife managers, ranchers, and farmers for variable, even bizarre, reasons. NBWC established a hunting season for crows (not protected) several years ago as an apparent (look-alike) sop to sportsmen to appease their persistent requests for raven hunting.

When Dr. Coate’s early raven studies became available, they were frequently mentioned in agency and commission discussions and used as justification for pushing U.S. Fish and Wildlife Service (USFWS) for higher raven depredation kill quotas. Fortunately, USFWS biologists understood the relative insignificance of the matter and the quota of 2500 raven kills/year was retained.

Nevada Board of Wildlife Commissioners (NBWC) now authorizes and pays for poisoning of about 2500 ravens each year in the forlorn hope that something useful will happen.    

(Ravens are protected by the Migratory Bird Treaty Act of 1918 and can be killed only in limited numbers by permit from USFWS.)

Parenthetically, raven numbers in Nevada are now estimated between 200,000 – 400,00 birds according to Partners In Flight Database. While that is a large number (believe it at your peril), not all ravens eat greater sage-grouse eggs, or predate on young desert tortoise.  Ravens have plenty of roadkill, dead domestic livestock carcasses and municipal dumps to keep them fed.

Now, though, ravens are pursued – i.e., ‘scapegoated’ – well beyond their importance on the ‘threat list’. Calls for higher kill numbers are heard every year. Dr. Coate’s raven studies are always cited as scientific justification for asking.

By killing ravens, wildlife managers and land management agencies claim that protection is being offered to greater sage-grouse; something useful IS being done, ergo, less pressure on agencies and managers to take on bigger issues with bigger political consequences.

Consider, for example, the political consequences to NBWC of simply poisoning 2500 ravens per year versus suggesting that domestic livestock be removed from public lands; or that greater sage-grouse hunting be ended (and face the wrath of angry sportsmen who bemoan ‘loss of opportunity’).

(Parenthetically, around 95% of approximately 100 million cows in the U.S. on any given day live on private property, not on public lands.)

Now, Dr. Coates has made a new contribution, suggesting that wild horses are properly placed on the greater sage-grouse ‘threat list’, no matter how distant their location from the top. Is it too much to imagine that future calls from sportsmen, ranchers, wildlife commissions, university researchers, and others for wild horse removals will be bolstered by ample reference to Dr. Coate’s new study?  I know that will happen.

Wild horses now have a nice new ‘coat of paint’ on them, freshening them up for future ‘demonization’ as major players in the greater sage-grouse saga … even though they are not. They will be ‘scapegoated’ as never before.

For sake of completeness, here is the current list of Nevada’s ‘scapegoats’: wild horses, ravens, mountain lions, and coyotes. Each of these animals (and a bird) is blamed for transgressions not entirely of its making. They are killed or removed for exaggerated ‘political’ or misguided reasons to spare management agencies from harder decisions. 

None of what has been said so far is meant to suggest that ravens and wild horses have no impact on greater sage-grouse populations in certain areas. Clearly, there is some impact. 

Rather, it is a matter of proportionality. The law has a notion that ‘proportionality’ should play a part in assessing legal penalties for human wrongdoers. Why does that concept not apply to ravens, wild horses, mountain lions, and coyotes?  Why should those species pay a greater price?

So, in the end, are we talking science – ‘politics’ – or a little of both? Sometimes it is hard to know.

You can decide.


Don Molde is a 50-year Reno resident, retired psychiatrist, co-founder of Nevada Wildlife Alliance, former board member of Defenders of Wildlife, and former board member of the Nevada Humane Society. He has been active in wildlife advocacy for 45 years. Support Don’s work here. 


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