June 22, 2008

'The more cows, the more tortoises'

Las Vegas Review-Journal

Vin Suprynowicz

A May 14 editorial in the Review-Journal cited a portion of Vern Bostick's study, "The Desert Tortoise in Relation to Cattle Grazing," published in "Rangelands," in June 1990.

This brought a letter from a newly arrived "expert" on the extent to which desert tortoises are allergic to having large ungulate grazers sharing their range, arguing that desert tortoises won't use cow droppings to get nourishment or moisture no matter how desperate their straits, and that "All leading tortoise scientists agree that cattle grazing and tortoises don't mix."

I'm not a "leading tortoise scientist," but I've been out on the range visiting with some of Nevada's long-time, multi-generation ranchers, and those experts tell a different story.

Cliven Bundy, who grazes the Mesquite allotment, says he's seen an exhaustive study compiled -- at great expense and under federal orders -- when the big Kern River natural gas pipeline was laid through Southern Nevada, counting the fewest tortoises in route miles where cattle and sheep hadn't grazed in recent years; many times higher tortoise densities in areas where cattle still graze; and the highest tortoise density of all right here in the Las Vegas Valley -- hardly evidence that this is some fragile creature endangered by the very presence of mankind and his infrastructure.

Seems like we might want to take a closer look at that document.

Not that such findings should come as any surprise. Cattle's presence on the land benefits tortoises in many ways. Cattle mean ranchers, and ranchers make some effort to reduce the populations of coyotes and ravens, which are the tortoises' main predators. Ranchers also clear out springs and pipe water to remote tanks, so both the ranchers themselves and their wandering cattle bring water to areas where deer, and doves, and quail -- and especially tortoises, who can't travel as far in a day as any of those species -- would otherwise find none.

Finally, cattle graze down brush, reducing the severity of range fires and causing tender new shoots to grow in closer to ground level, where tortoises can more easily reach them.

Meantime, I talked to Vernon Bostick on the phone last week.

"They claim cow dung is 'nutritionally deficient,' Vern laughs. "It's high in nitrogen and that's USDA Bulletin No. 49. Cows absorb 20 percent, pass 80 percent of the nutrients through their system. And they graze stuff too tough for tortoises to masticate. ...

"Each cow makes 12 deposits a day, and it's 90 percent water," Vern explains. "Remove the cattle and the tortoises are dependent on rainfall; they have to hold their urine ..." which can result in illness and, eventually, death.

Mr. Bostick followed up with a lengthy letter.

"The tortoise fraternity will (try to) discredit what I write because I am not a herpetologist. Deciding if Nevada tortoises should be named as a distinct subspecies is herpetology. Managing animals on the range, wild and domestic, is range management. I am not encroaching on their field; they are encroaching on mine. And they are awfully short on clues. ...

"Rob Mrowk in (his) letter to the editor opened his rebuttal of my 1987 report ... with this statement: 'All leading tortoise scientists agree that cattle grazing and tortoises don't mix.' whatever that means. ...

"Before I offer my rebuttal of the above nonsense allow me to qualify myself as an expert witness. ..."

Vern has a M.S. in biology from UNLV and a B.S. in range management from Colorado State. He wrote the text for a course in judging range condition and trend (whether the range is improving or deteriorating) taken by all U.S. Forest Service personnel working in Arizona and New Mexico.

"I will call History as my first rebuttal witness," Vern writes. "Before there were any cattle grazing on the western range, the desert tortoise was extremely rare. The first Spanish explorers found roasted shells at old Indian camps but never saw a live tortoise. They concluded that this unique reptile was extinct. ... Spanish colonists brought cattle with them. Cattle and tortoise have shared the same range for more than three centuries in some places and for more than a century everywhere. ...

"The following quotation is from Kristin Berry's 'Tortoises for Tommorrow':

" 'Long-time desert residents in California notes extraordinary densities' (in the early thirties ... when cattle numbers peaked) 'that could have been as high as 2,000 per square mile.'

"A member of the survey party in Antelope Valley in 1933 saw over 100 tortoises in one place at one time. He told Kristin Berry that tortoises 'were everywhere ... all over the ground' (and so were cow pies.)

"From the early thirties to the mid eighties the number of cows grazing on federal range was reduced about 90 percent. ... From the early thirties to the mid eighties tortoise densities declined from 2,000 per square mile to 65 i.e. 97 percent (Medica, oral communication) in response to reduced cattle grazing. Kristin Berry used this drastic reduction in tortoise population to get the desert tortoise listed as an endangered species. Then she used this listing to 'get rid of the cows.' Mission accomplished.

"History reveals a positive correlation between cattle and tortoise populations: the more cows on the range, the more tortoises, and with fewer cows there will be fewer tortoises. There is ample evidence that this correlation is a cause and effect relation.

"My 1987 report reviews all cases where cattle grazing was eliminated and tortoises had exclusive use of the range ... In every case elimination of cattle grazing resulted in a smaller tortoise population.

"The most complete data is from the Beaver Dam Mountains. Woodbury and Hardy reported a tortoise population density of 150 per square mile in 1948. BLM reduced cattle grazing a few years later and eliminated cattle in 1970. Coombs reported a tortoise density of 39 per square mile in 1974. In these 26 years cattle use was reduced 100 percent and tortoise numbers were reduced 74 percent.

"These tortoises were doing so poorly a veterinarian, Dr. Jarchow, was consulted. He reported all six specimens were suffering from osteoporosis caused by a protein deficiency in their diet. Dr. Jarchow examined five specimens from the same mountains that shared their range with cattle. He reported these specimens were all healthy and well nourished. The historical record proves conclusively that tortoise thrive when cattle are on the range with them and without cattle grazing they are malnourished and unhealthy and their numbers plummet.

"The tortoise recovery program is based on a popular but false premise that the desert tortoise is endangered because of competition with cattle for forage," Vern Bostick concludes. "The recovery team has had a lot of time and they have spent a lot of money. I think we should have an accounting. How many tortoise populations have they recovered and to what extent? Have any tortoise populations decreased since their program began? All new" (Southern Nevada) "home-buyers pay $500 into the recovery program. I believe they have a right to know what they are getting for their five hundred bucks."

Sounds reasonable to me.