TRAVEL LOG 2003
(A Note To Those Concerned About Our Dwindling Wild Sheep)
By
John Mionczynski, Wildlife Consultant
Many things can be said about the 2003 field season for the Bighorn Sheep/Selenium Study. It was productive. So much data was gathered on chemistry of rain, forage, and soil that it will take a while before it is all analyzed. There is still a batch of analysis we are waiting to get back from the Olsen Biochemistry Lab.
Andrew Algeier did a fine job as chief field assistant this year. He kept up with the sheep for health observations and ran virtually all the tests at our laboratory on Middle Mountain where he recorded some of the highest nitrate levels in rain we've yet seen…. as high as 11 parts per million (ppm) almost twice the previous record.
Laney and her friend Deb Robinett spent a week doing photo/artist studies on the sheep and assisted us in locating ewe/lamb groups. It was a nice mix of work and pleasure for us all.
By far the most interesting part of this season began August 2nd when I took off on a whirlwind tour of sheep ranges around the West. The goal was to gather baseline data on the availability of selenium to bighorn sheep outside Wyoming. This was spurred by my findings last year that a dwindling sheep population in Idaho and a mountain goat population in British Columbia with White Muscle Disease (WMD) both had forage selenium levels essentially equal to the dwindling Whiskey Mountain herd. Stable populations also sampled last year had ten times (10x) those levels! Could this be a geographically widespread correlation? Do all sheep populations with low selenium intake have low lamb survival? Is Nitrate pollution in precipitation responsible? The only way to answer these questions in my estimation was for Andrew to continue the nitrate studies on the Middle Mountain sheep range while I went out on the road and collected forage species and soil from sheep herds around the West, both declining and stable populations. With the help of the Nature Conservancy, The University of Wyoming, The Lucius Burch Center, and most importantly private donations of money and time from all of you (people who simply care about wild sheep), we succeeded in gathering a good deal information.
Arrangements were made with officials in Colorado, Utah, Nevada, Idaho, and Montana. All were very helpful and interested in this work. Fifteen sheep ranges were sampled in thirty days. This has to be some kind of record for going up and down mountains. (Speaking of records, the air conditioner in my truck quit the day I left, and it had to be the hottest summer on record in the West!)
The bulk of the samples were collected in Colorado and Nevada where I received red carpet treatment. DOW (Division of Wildlife) biologists and wardens and private individuals who are fans of bighorn sheep took time out to show me where the sheep were, their migration patterns, mineral licks etc. Even a deputy sheriff took me into one mountain range. Some of these accompanied me up into the rocky crags and helped collect forage and soil samples.
Dr. Rob Roy Ramey, Curator of Zoology, at the Denver Museum of Nature and Science and his assistant Lance Carpenter, took me to many high sites (a few 14,000 footer's) in their study areas in Colorado. For the last three years they have been following up on our Wyoming studies south of the border in the Front Range with positive results. My thanks to Janet George of the Colorado DOW and Mike Cox of the Nevada DOW and all of their associates for their time and energy. The level of cooperation was overwhelming! These people genuinely care about wild sheep and their mysterious declining numbers. We began sampling several populations in the Big Thompson Canyon west of Fort Collins then south to the St. Vrain River.
Further south we visited two sheep ranges, with mountain goat populations, near Mt. Evans that had low lamb production followed by the Georgetown herd and the Kenosha herd. Of these, the Kenosha herd had the least productive lamb crop and is considered to be in serious danger of extinction. Its forage selenium level was below the detection limits (<0.020 ppm). The Georgetown herd on the other hand had a relatively high lamb survival, but had a low forage selenium value (0.0240 ppm), an apparent contradiction until Dr. Ramey revealed that this herd came down to Interstate 70 to eat road salt quite high in selenium. A very important finding! Studies are currently being conducted to prove the connections.
From there it was south to Mt. Sherman and three sites in the South San Juan's almost to the New Mexico border… my thanks to Julie Davis who knows the Colorado backcountry like the back of her hand and guided me to six of the sheep summer ranges. These herds had generally been suspected of poor reproductive status, although reliable counts were not always available, and all had low selenium levels.
After a few more sites in Colorado and one in southern Utah, it was on to five sites in Nevada, one was the poorest herd in the state. Its forage/selenium was a low 0.03.
The Granite Mountains in Nevada near the California border also have reports of poor reproductive success and selenium levels were near and below the detection limits. Most of the rest of the sites in Nevada, Hells Canyon, Idaho, and western Montana require more data and interpretation in the coming months, but so far the hypothesis seems to be holding up.
This has become a personal crusade for me over the years, so I feel personally indebted to all the private donors as well as The Nature Conservancy and The University of Wyoming and especially to Laney Hicks for raising the awareness of so many people to this work through her wonderful painting of the ewes and lambs of Middle Mountain.
GENERAL RESEARCH SUMMARY * 2003
1. Selenium uptake by plants at high elevations in granitic soils appears to be related to the timing of nitrate deposition relative to the stages of plant development. This deposition affects selenium availability not only to Bighorn Sheep populations but also the populations of marmots and pikas, which have been declining within the same time period as the sheep.
2. Research now being analyzed from work done this summer indicates that declines of these
three species is not limited to the Wind River mountains. Bighorn Sheep declines extend
from New Mexico to central Canada. Corresponding declines in pikas and marmots extend at
least from New Mexico through Wyoming with no information yet available from Canada.
The University of Wyoming has recently attempted to look into marmot and pika declines in
the Whiskey Mountain study area as well as other Wyoming locations to see if they are
related to selenium deficiencies.
2. In the Front Range of Colorado many Bighorn herds have dangerously low lamb success and
low forage selenium levels. Yet in the Georgetown herd, located in the middle of these
declining herds, with equally low forage selenium, lamb numbers remain high. Interestingly,
these wild sheep have become a traffic hazard on the shoulders of Interstate 70 where they
eat accumulated road salt. Recent analysis of this road salt by Dr. Rob Roy Ramey of the
Denver Museum of Nature and Science yielded available selenium levels far surpassing those
Found in the mineral blocks put out for the Whiskey Mountain herd.
