WSF Grant-in-Aid Update: Bighorn Sheep Capture - Scottsbluff, Nebraska Wildcat Hills
With the help of Grizzly Outdoor Corps of Winston-Salem, NC, WSF made a $50,000 challenge pledge at our 2022 Chapter & Affiliate Summit to raise money to purchase GPS tracking collars for this project. In five minutes, another $110,200 was raised. Iowa FNAWS contributed $50,000, and the Gilchrist Foundation of Sioux City, IA, added $25,000. A dozen WSF Chapters and Affiliates each pledged $5,000, including Utah WSF, Midwest WSF, Washington WSF, Arizona Desert Bighorn Sheep Society, Montana WSF, Texas Bighorn Society, Wild Sheep Society of BC, Oregon WSF, Alaska WSF, New Mexico WSF, California WSF, and Idaho WSF. Karen Gordon of Alaska also individually contributed $200.
These types of capture, test, collar, and releases can be broken down into segments.
Monday, February 27. Phase 1 - Capturing Sheep
The goal today was to use helicopter net gunning to capture 20-25 bighorn sheep, ewes, and lambs. Wind gusts were expected over 30 mph, so for safety reasons, the helicopter capture crew shut it down after bringing in seven sheep.
Captured sheep are carried on stretchers from the drop site by the ground team to sawhorses set up in the biological testing area. Phase 2, taking biological samples, is up next.
Nebraska was once home to abundant bighorn sheep populations. By all accounts, they were gone by the early 1900s. Repopulating the Cornhusker State began in 1981 by translocating surplus wild sheep from other states. Today there is an estimated population of 250 bighorn sheep.
With the winds subsiding in the afternoon, the crew was able to capture 24 bighorn ewes, lambs, and one young ram.
WATCH VIDEO HERE
Tuesday, February 28. Phase 2 – Processing Sheep
The health and well-being of the sheep are paramount when collecting necessary biological samples. The capture team, each knowing their roles, work fast. The sheep's temperature is monitored to ensure it remains below a stress point. Blood samples are drawn, nasal and tonsil swabs are taken, and weight and age are recorded. If the sheep already has a GPS collar, the collar's condition is evaluated and replaced if need be. Sheep w/o collars receive one with a matching ear tag.
The goal is to have a biological record of each animal's health and to test for M.ovi., a pathogen they can get from contact with domestic sheep or goats, or other already-infected bighorns; M.ovi compromises bighorn's immune system, making them susceptible to die-offs from respiratory pneumonia. If positive, the tests also reveal which strain of M.ovi so biologists can make an informed decision whether to release the sheep where caught or whether they are suitable to move to a new habitat.
Comparing field, on-site testing results (via a Biomeme unit, a field PCR amplification tool) with overnighted, diagnostic lab results raise the certainty of detecting a bighorn sheep's respiratory pathogen status. For the first time, highly-trained dogs were used on this capture to detect/not detect M.ovi from sniffing bighorn sheep fecal pellets. These comparisons aim to ensure the highest degree of confidence in positive or negative results, enabling the wild sheep manager and/or wildlife veterinarian to make the most-informed, prompt decision as to transplanting/relocating that bighorn or not.
WATCH VIDEO HERE
Thursday, March 2. Phase 3 - Releasing
Over two days, 36 bighorn sheep were captured, sampled, and processed – 35 ewes, lambs, and one young ram.
From the advance capture/testing work in September 2022, in an area where M.ovi had not been documented historically, and with these first sheep known to have tested negative, NGPC opted to release some of these newly captured sheep after processing. Some were even given a ride back. Others held in trailers awaiting test results were also released on-site.
All in all, goals were accomplished, data on 36 bighorns were added to NGPC’s long-play management dataset, two new, promising on-site disease testing methods received “real-time” field trials, and the opportunity to compare/contrast the diagnostic field methods. All captured bighorn sheep were released safely; post-release monitoring (?) will assess their short-term movements and survival.
WSF salutes the Nebraska Game and Parks Commission for coordinating this effort, South Dakota State University and Henry Doorly Zoo for providing veterinary services, and the Nebraska Department of Agriculture, WSF Affiliate the Nebraska Big Game Society, and the many volunteers who made this capture possible and successful.
WATCH VIDEO HERE