Tuesday, January 6, 2009

Sheep Capture, Part 1: Overview

During the first weekend of January 2009 members of Montana Fish, Wildlife & Parks, Utah Division of Wildlife Resources, and a crew from Pathfinder Helicopters of Salt Lake City captured 60 bighorn sheep near Sun River Canyon. While this wasn’t something new--Montana has been translocating bighorns since before 1941—the science behind managing bighorn sheep is unique.

As the sun rises on Saturday, 3 January 2008, the temperature is about -28 F. This view is taken looking east of Montana's Rocky Mountain Front on the Benchmark/Willow-Beaver Creek Road southwest of Augusta. Mountain on the right is Haystack Butte.

As one of Montana’s Rocky Mountain bighorn sheep nimbly hops from crag to crag or casually grazes on a rocky ledge in frigid weather it is easy to believe them hard, sturdy animals.
In their own right, they are. However, like many of God’s creatures they are at the mercy of humans.

Some experts believe that bison were the only animal in the United States to outnumber bighorn sheep before Lewis & Clark and the subsequent settlement of the west. Diseases and unlimited hunting decimated wild sheep in North America. Domestic sheep carried diseases that affected wild sheep much like human diseases ravages Native Americans.

Bighorn numbers were so low in Montana that legal hunting of the species was closed from 1915 until 1953. A few sheep were brought from out of state to start new herds. Twelve sheep from Banff, Alberta were released at the Moiese Bison Range in 1922, and 16 sheep from Colorado were released in the Missouri Breaks in 1947.

Even with these measures, Montana’s bighorn numbers remained small. Montana Fish, Wildlife & Parks estimated that there were only 1200 bighorns in Montana in 1950.

Since then wildlife managers have worked to grow Montana’s bighorn population. There were about 4800 by 1997. That is the good news. The not so good news is that crowded herds can damage habitat and allow diseases to race through a herd quickly. During a trapping operation in the Sun River area in January 2005, Quentin Kujala, Management Bureau Chief, FWP Wildlife Division, (then area biologist) and Graham Taylor, Region 4 Acting Regional Supervisor agreed that having sheep numbers above target was “spooky.” Each voiced their opinion that being under target and working toward it was easier than keeping a population at target and healthy.

In January 2008, current area biologist Brent Lonner said there is a minimum of 900 sheep in the Sun River area. He said that FWP’s goal is to stay within 10 percent of their target of 775 head for the Sun River complex. That would translate into a herd of 852 sheep.

To reach that target FWP uses both hunting and translocating sheep to locations both in and out of the state. Lonner said that he has taken a wide range of comments concerning translocating Montana bighorns. Some believe it is a good program, some don’t care to have Montana sheep taken from the state, and still others wonder why objectives can’t be met by allowing more hunting.

Locations for sheep taken out of Montana are sought only after FWP finds no areas that need sheep within the state, Lonner said. He added that Montana only pays for some manpower and a few tests when sheep are moved to other states. All other trapping and translocating costs are born by the receiving states. It cost about $900-$1000 per sheep to capture, do testing and blood work. That was paid for State of Utah with funds provided by the Federation of North American Wild Sheep. Additional cost for manpower, radio collars, per diem and truck costs were born by Utah.

Kujala addressed the reason for not allowing more hunting best when he said that if 30 more ewe permits were issues for two of the areas within the Sun River complex, hunters would focus on a specific piece of ground and harvest sheep in the most accessible areas. In contrast, he said that by capturing a few animals over a wide area sheep herds continue to habitat areas were sheep currently live. He and most wildlife biologist contend that sheep are not pioneers--like whitetail or elk. Bighorns avoid dispersion and once eliminated from a specific area tend to not return of their own volition.

Since sheep that have been extirpated from areas won't recolonize, and other areas have an excess of sheep, which may destroy habitat or pose a disease risk to their own herd, managers believe tranlocating sheep is essential.  Kujala said, "Translocating is prescribed, almost necessary in sheep managment."

The 60 sheep that were captured in the Sun River area this winter were released to Utah's Uitna Mountains.  Randall Thacker, a biologist for Utah's Division of Wildlife Resources, said, "All the sheep were released Monday (5 January), and they look great."

Links to this post:

Sheep Capture, Part 1: Overview

Sheep Capture, Part 2: Net Gunning

Sheep Capture, Part 3: Processing

Sheep Capture, Part 4: THERE IS NO PART 4

Sheep Capture, Part 5: Past and Future

Sheep Capture, Part 2: Net Gunning

Capturing sheep has evolved. Until a few years ago, bighorns were luring into makeshift corrals with hay. That method wasn’t always effective. It depended on weather and managers never knew how many sheep they might catch. There was also the threat of mountain lions attacking sheep in the trap at night before FWPs personnel arrived. Montana Fish, Wildlife & Parks wildlife biologist Quentin Kujala lamented sitting in his pickup watching sheep traps all night in case mountain lions stopped by for a quick snack.
Montana Fish, Wildlife and Parks personnel untangle nets before repacking. Photo was taken in 2005 at the same site used in 2009 (day two) just below Gibson Dam, Sun River, Montana. Sheep taken here in 2005 went to Idaho.

The latest method being used is called “net gunning.” Net gunning requires a crew of three: pilot, a gunner and a mugger. After finding the sheep, the pilot then herds the sheep to a point were the gunner, who is standing on the chopper’s skid, shoots a nylon net that tangles the feet of the animal. The third man, the mugger, leaps from the chopper and puts a blindfold over the bighorn’s eyes. Blindfolds keep bighorns calm much the way blindfolds keep horses calm. He then hogties the bighorn and lashes it in a sort of mesh envelope that is then slung under the helicopter.

The past several years, Montana Fish, Wildlife & Parks has relied on Pathfinder Helicopters of Salt Lake City for net gunning services. The three-man crew this year consisted of pilot, Steve Collins; Gunner, Phil Wright; and Mugger, Ephen Collins, Steve Collins son.

Bighorn lamb still tangled in net after being net-gunned. Blind fold keeps the sheep calm. 2005 photo.

All three are from New Zealand. Both Collins are from Rotorua on the north island, although Steve Collins has a three-year work permit, and wishes to obtain residency. He said, "There is much more wildlife to capture in North American than in New Zealand." Wright is from Haast, which is on the south island. This is Ephan Collins first year as a worker. Steve Collins has been net gunning since 1981, and Wright's net gunning started in 1982.

Before coming to the Sun River area to capture sheep, the Pathfinder crew was in southwestern Montana net gunning moose. Those moose were only checked for physical condition, collared and released. Weather had delayed that sheep capture from 24 Dec until 3 January.

On 2 January, heavy snow, sub-zero temperatures and high winds had closed many highways in the state. Most FWP personnel didn't expect the Pathfinder crew to fly in such conditions, but pilot Collins braved the elements and flew his MDH500 helicopter less than 100 feet above the ground, following U.S. Highway 87 to Augusta, Montana.

New Zealander and pilot Steve Collins gently eases the last of five bighorns to the ground. Collins leans half his body from the chopper to see that none of the sheep are piled on others.

On the night of 2 January, the weather abruptly changed bringing near perfect conditions for sheep capture.

Clear skies and new snow made hunting for bighorns easier. The minus 28 temperature gave additional lift to the chopper's blades and reduced the stress bighorns experience from moderate-to-high temperatures. Nearly non-existent wind made flying easier.

Thirty-two bighorns were captured on the 3rd near the Willow Creek drainage about 18 miles west of Augusta. Two of the sheep had some unknown lesions on their nose and lips and were released. A total of thirty bighorns were loaded into a horse trailer for the Utah trip.
The perfect day was marked by only one mishap.

Sometime during the day, a hard landing had flipped on the helicopter's emergency beacon. A passing commercial airliner picked up the signal and reported it. The Montana aviation people, Montana Highway Patrol and Lewis and Clark Sheriff's Department were all contacted.

The Sheriff's Department put a single engine plane up to find the "downed" helicopter. No one on the capture crew knew anything about it until returning to Augusta late that night.

Pilot Collins coming in with five sheep "daisy-chained" under the chopper. When more than three sheep were hauled, the gunner and mugger had to stay behind, as the chopper didn't have the power to haul three people and five bighorns.

After the emergency, the weather changed yet again.

By morning of the 4th, temperatures moderated a bit to around minus 5, but the wind pickup to over 60 knots. Pilot Collin downplayed the wind's effect on his flying, instead he complained that the wind simply “took” the net when it was fired. That caused many dry runs, and by 3 p.m. it looked as if thirty more bighorns would not be bagged.

Each bighorn that Pathfinder captures cost the State of Utah more than $650. Each bighorn that they do not capture is $650 NOT in Pathfinder's coffers. The thought of a short day must have weighed on the Pathfinder crew, because they would return to the administrative area, load up all their nets, take-off and return with not one, two or three bighorns, but with five daisy-chained underneath. With such a load, the gunner and mugger had to stay behind.

Hauling a single sheep on Day One near Willow Creek, Montana. Mountain on left is Lime Reef. Mountain on right is the south end of Sawtooth Ridge.

Just before dark, 30 sheep had been captured.

After net gunning Montana's sheep, the Pathfinder crew was headed to Ontario, Canada, then to Manitoba, Canada, then British Columbia, Canada, back to Montana and then to Mexico. Animals they were slated to capture ranged from moose, to bighorns, to caribou, to wolves and mule deer.

Steve Collins said that Pathfinder's charges ranged from $400 to $3500 per animal. He said it depended on what animal they were after and how many times those individual animals had been net gunned before. He said that every time an animal is net gunned, it gets smarter. He said, "The worst are wolves. They are the smartest. Wolves that have been caught five times or more never come out of the trees."

Sheep Capture, Part 3: Processing

Subzero cold was occasionally punctuated by swirling snow and biting propwash each time the Pathfinder Helicopter crew brought more bighorns.
Helicopter lifts off after refueling. MT FWP personnel untangle nets for the next capture. Gibson Dam can barely be seen behing chopper. 2005 photo.

Occasionally the bighorns are placed in the back of the chopper instead of being hauled underneath. 2005 photo.

As the chopper's noise receded biologists from Montana Fish, Wildlife & Parks and Utah Division of Wildlife Resources, as well as other personnel from MT FWP and several volunteers, all scurried to process the sheep as quickly and efficiently as possible. There was little chit-chat. Biologists wanted to keep the bighorns' stress levels low--so talking was discouraged.

FWP Lab Supervisor Neil Anderson palpates for a vein before taking a blood sample. 2005 photo.

The processors job wasn't as dangerous as the helicopter crew's, but it was just as exacting. Each bighorn had its temperature checked, at least 30 ccs of blood drawn, its nose, throat and ears swabbed, fecal pellets taken, body condition checked, and checked for overall health.

Site of first days capture effort. Deep snow made this the "end of the road." Photo is looking west, up Willow Creek (notch in left of photo). Fairview Mountain is center and right center.

While there was no specific order to the operations, checking each bighorn's temperature was usually one of the first procedures. Any sheep that had a temperature over 104 degrees, or was panting, was doused with water. Temperature and panting are indications of stress, and the biologists wanted to stress the sheep as little as possible.

Montana Fish, Wildlife and Parks Lab Technician Rose Jaffe draws blood from a young ewe on Day Two of the capture effort. MT FWP veterinarian Jennifer Ramsey instructs in proper technique. Photo taken below Gibson Dam, Sun River, Montana.

MT FWP veterinarian Jennifer Ramsey, 34, said that the blood would be separated and tested for many diseases, including Brucellosis, Blue Tongue, Anaplasmosis and Bovine Viral Diarrhea. The nose and throat cultures would be checked for Pasteurella (pneumonia) and microplasm. The ear swabs would be tested for psoroptes mites, which could indicate they carried scabies. Ramsey also conducted the physical to look at overall health.

The metal frame work is a speculum. The speculum is used to pry the mouth apart so cotton swabs can take samples from the back of the throat. The samples are later tested for pastuerella and microplasm. 2005 photo.

Neil Anderson, 43, MT FWP Wildlife Laboratory Supervisor gave each bighorn what would appear to be some sort of massage. It wasn't a massage, by palpating the back and loin areas of each sheep Anderson could estimate how much body fat a sheep carried and know their general body condition.

MT FWP Wildlife Technician Kevin Hughes takes samples of earwax at the Day One site near Willow Creek. Cotton swabs with earwax are tested for psoroptes mites, which may indicate the presence of scabies.

Most of the testing was paid for by Utah DWR. However, Anderson said some was paid by Montana. Many discussions developed between breaks of arriving bighorns. In relation to the costs of testing, retired MT FWP wildlife biologist Terry Lonner said, "Without knowing the health of each species there is no way to estimate the health of the entire ecosystem."

Terry Lonner, his son Brent Lonner, who is the current area biologist for the Choteau/Augusta area, Region 4 Acting Supervisor Graham Taylor, and Game Warden Dave Holland spent much of the "down-time" untangling and repacking the capture nets. Region 4 Wildlife Area Manager Mark Schlepp checked-off operations on his clipboard to ensure that every sheep was tested, tagged and radio-collared (half of the sheep were radio-collared.) Schlepp joked when he said, "I can run a pencil, so I must be qualified for this job." Maintenance workers, Tim McWilliams and Stan Buresh did all the "heavy-lifting."

Utah Department of Natural Resources Biologist Brian Maxfield attaches a radio collar to a bighorn.

At the end of day one, there had been a problem with the emergency beacon for the chopper. A different but more taxing problem developed at the end of day two. After two long, cold days everyone was ready to have a shower, food and a good rest, but one more obstacle remained. The 60+ knot winds on day two had built a four-foot high by 30-foot long snow drift at the entrance to Sun River Canyon. After an attempt by one pickup, which had to be retrieved with chained-up pickup, a route was found through the ditch and over a hill.

During the 40 minute trip back to Augusta, everyone stripped off hats, mittens, neck-gaiters and face warmers. There was little talk.

Sheep Capture, Part 5: Past and Future

Group of bighorn sheep a couple hundred yards from Gibson Dam. Photo taken fall 2000.

This article will be slightly longer than normal. Hopefully it is worth the read.

Since the first unsuccessful attempts at capturing sheep in Montana in 1938, the capture efforts have evolved from simple corral and hay set-ups to using helicopters and net gunning, but the need to capture and translocate bighorns has remained constant.

It has been mentioned in previous articles that capture and translocating bighorns is essential. In the overview to this series of articles, Montana Fish, Wildlife & Parks Wildlife Management Bureau Chief Quentin Kujala was quoted, “Translocating is prescribed, almost necessary for sheep management.”

Without pouring over books and manuscripts relating to sheep management or talking to many wildlife biologists, basics reasoning behind Kujala’s statements may not be apparent. To know where Kujala, and other biologists, are coming from we need to take some stair-steps through the building blocks that lay the foundations in bighorn wildlife management.

The first step is that sheep are not elk or whitetail. Obviously. The difference is that sheep act more like sheep than elk or whitetail—they “follow the leader.” A bighorn herd relies on the knowledge base held by the oldest rams and ewes. A knowledge base that is lost—through disease, or over-hunting takes generations to recover.

In further conversations with Kujala, he named a group of sheep that lived in an area he referred to as “Grizzly Basin,” that if lost, would be nearly impossible to replace. (The exact area isn’t important.) What is important is the why.

Studies of bighorns reveal that most sheep are afraid of timber. American (New World) sheep rely on rocks and cliffs, and their powerful muscles to escape predators. (Old World sheep of Asia evolved to be more like America’s pronghorn antelope, using longer leaner bodies and speed to outdistance predators.) Timber is a weakness their capabilities don’t address. But, Grizzly Basin has a lot of timber. How can bighorns that are normally afraid of timber seem to exist where timber exists?

In Montana it takes 120 years for a conifer to grow to a diameter of two- feet. Compare that with the oldest bighorn’s lifespan of about 20-years. While the conifers grow, at least six generations of bighorns have evolved and expanded their knowledge base to include living in, and around timber.

With that in mind, the impossibility of replacing sheep in Grizzly Basin looms large. The only apparent solution to replacing that heard would include: clearing the timber, relocating sheep to the area and letting another six generations of bighorn’s build a knowledge base that includes slow-growing timber.

The second step would answer, “Why are sheep different than elk and whitetail that thrive in habit that is very near and sometimes overlaps?” It is difficult to answer that question directly. There is very little fossil evidence to trace sheep development. In some respects biologists know less about the supposed evolution of sheep than experts on dinosaurs know of the giant reptiles.
Many of the prehistoric reptiles and fish lived where there was mud, silt and other soft deposits that made preservation of bones easy. Sheep lived on and around glaciers, cliffs, rocks and fast moving torrents. As Ice Ages came and went, natural physical processes broke, smashed and ground sheep remains to minute elements of glacial till.

Without fossilized remains biologist look at contemporary sheep patterns and extrapolate from there.

One contemporary pattern is that sheep find a static balance within their ecosystem. In an amazing biological adaptation much like wolves reaching capacity in their ecosystem, when a herd reaches the ecosystem’s limits, reproduction slows. (Although wolves are different in that they do disperse.) In a growing herd, bighorn ewes will begin breeding at two-years, but when the upper limits are reached, ewes don’t breed until they are three or four-years old.

It is believed that the bighorns that survived waves of glaciation during the Ice Ages did so by being “sheep.” Sheep that stayed with the herd and relied on the herd’s knowledge base in relation to winter and summer ranges survived. Sheep that left the herd to seek “greener pastures,” perished.

That is not to say that all sheep that stayed with the herd survived. Hardly. Sheep that died while with the herd actually made room for subsequent sheep to thrive, or at least survive to another day.

Bighorns that survived another day within the somewhat closed yet harsh glacial environment never developed resistance to diseases brought by domestic sheep.

Fragility of bighorns is probably a third step in managing bighorns. FWP biologist Brent Lonner put much of this into perspective in a recent email. In it he said, “Ideally, by translocating wild animals, such as sheep, we are reducing the threat of major disease and die-off events (other instances of relocations can also relate to limiting game damage problems in areas as well). This has occurred several times in recent history, one primary reason being related to too many animals on the landscape. When a disease is introduced or propagated in a population, if animal numbers are too high, it doesn't take much for animals to come into contact and the disease to move through population at a relatively fast rate - especially with sheep due to their susceptibility to disease. I often wonder if one of sheep's primary goals in life is to find a place to die.”

There are more than three steps in bighorn management. As wildlife experts observe sheep living, thriving and dying, management thought, theory and application will evolve with these hardy, and ironically, fragile animals. This four-article series is a thumb-nail of Montana’s, and the west’s, attempts to keep bighorns hardy and thriving in a rocky and changing environment.
I owe thanks to wildlife officials of Montana, Utah, Idaho and Nebraska.

I especially need to thank Quentin Kujala and Brent Lonner for their input; FWP Wildlife Laboratory personnel; and, Dale Toweill from the Idaho Fish and Game. Dr. Dale E. Toweill and Dr. Valerius Geist co-authored Return of Royalty: Wild Sheep of North America. While many books and online resources helped with these articles, Return of Royalty was both a starting point and a tightly packed chest of information. Filled with many high-quality photos it makes a great coffee-table book.