Hunting of bighorn sheep ewes could produce more trophy rams

December 21, 2017, University of Wyoming
Hunting of bighorn sheep ewes could produce more trophy rams


Although contrary to prevailing notions, hunting of female bighorn sheep may well be one of the most effective ways to increase the number of trophy rams in North American bighorn sheep populations, according to researchers at the University of Wyoming and other institutions.


That's because such harvests would make more forage available to growing rams and, importantly, their mothers—boosting their nutritional levels, a factor that has been shown to be more important than genetics in producing rams with large horns, the researchers say.

Their conclusions are detailed in a paper that appears in a special section on management of mountain sheep in the Journal of Wildlife Management, a peer-reviewed, scientific journal devoted to the ecology of nondomesticated animal species and published by The Wildlife Society.

The paper's lead author is Kevin Monteith, assistant professor in UW's Haub School of Environment and Natural Resources, Department of Zoology and Physiology, and the Wyoming Cooperative Fish and Wildlife Research Unit. Also contributing was UW master's degree student Tayler LaSharr, along with researchers from the University of Idaho, the University of Nevada-Reno, the University of Alaska-Fairbanks and the California Department of Fish and Wildlife.

Unlike management of many other big-game species in the American West, there are few hunting opportunities for bighorn sheep ewes—in part, because of tradition and public resistance to the idea. But, Monteith and his colleagues say that not only could hunting of females improve nutritional conditions, leading to rams with bigger horns; it also could help stabilize bighorn sheep populations, reduce the frequency and severity of die-offs from diseases, and increase opportunities for hunters.

"We acknowledge and fully appreciate that initiating female harvest may conflict with hunting and management traditions…," the paper reads. "(However), if production of large, trophy males remains an important management objective…, then we contend that management programs should integrate monitoring of nutritional status of populations and, where evidence indicates nutritional limitation through density dependence, seek to regulate abundance and per capita nutrition via harvest of females."

For decades, concerns about declines in the numbers of trophy rams have focused on the evolutionary effects of hunting such large males, as removing those animals from the gene pool could lead to fewer large-horned offspring. But, while horn size is known to be hereditary, a growing body of evidence shows that age and nutrition frequently override genetic contributions to the size of horns, the researchers say.

"Given the hyperbole surrounding trophy management and big horns, we suggest the importance of females in the management of mountain sheep has been largely forgotten," the scientists wrote. Those impacts include the lifelong effects of the physical condition of ewes during and after pregnancy on growth of their male offspring, as well as the overall nutritional condition of sheep herds where their numbers exceed what available habitat can support.

"Ultimately, we call for greater recognition of the pervasive role of females in the production of trophy males, and that, accordingly, females be better integrated into harvest and management programs," the researchers concluded.



Read more at: https://phys.org/news/2017-12-...trophy-rams.html#jCp

In Alberta, We learned this through experience and put it into practice back in the Eighties.

Unfortunately those Bios have retired, and the new ones are more interested in limiting all sheep hunting instead of using these techniques to produce a healthier and more vigorous sheep herd.

Glad to see this back in the light.

Ultimately Wyoming does a shit job of managing wild sheep. I know several people that drew sheep tags and hunted for the majority of the season and did not see an adult male ram, let alone pull the trigger on one.

I am probably 12-14 years from having enough points to guarantee a shot at a tag.

The state oversells sheep tags, and they are trying to kill ewes just to raise revenue.

quote:

just to raise revenue.

That seems a common theme in a lot of wild life agencies.

Money is more important then the wildlife or the hunters.

We had a change in the bear regulations in Wis. the only concern of the DNR was how are we going to replace the revenue.

Not was if it was better or worse for the bears or the hunters.

My son had a ewe tag here in Montana we went three times and never saw a sheep.

I don't know how good or bad a job WY does of managing their sheep. I think that their hands are somewhat tied. Wy is experiencing some large reductions in revenue. The Wy game and fish keep seeing their funding cut. The legislature sets/raises license fees. I'm sure the F@G make suggestions. I think that they do the best that they can with sheep.
I killed a ram on a 10 day hunt 5 yrs ago. With that little experience I would ask if those failed to take a ram went the DIY route or hired a guide? One of my acquaintances failed to take a ram after drawing. He is older and hunted perhaps 4-5 days. He also didn't hunt very hard when he did.
Because of the point system the majority of sheep hunters are older. Even those with horses may not be hunting where the sheep actually are. Some units are tough without snow to bring them out of Yellowstone.
I'd bet that half of those hunters that fail to connect didn't get into where the sheep really are. From the WY G@F website they issued less than 200 permits for the WHOLE state in 2015. Success overall was almost 80%. 3 hunters did not hunt. Non-residents were over 90% successful.
In 2016 210 permits issued. 8 did not hunt at all and the success rate was 82%. Still just over 90% for non residents. Probably not ideal, but most hunters seem to get their ram.
Bruce

I think there are a lot of areas that are over sold. He hunts an area for elk near Dubois, that he has hunted his entire life. I don't know how many tags were drawn in 2011 or 2012 the year he hunted it. Union Pass area not sure of the unit number or name.

He has horses, and spent over 40 days on the mountain looking for rams. Never saw an adult ram. He is convinced that the state oversold the hunt.

His story seems to be a common one.

The wilderness areas tend to have a higher odds of kill. At least according to www.gohunt.com odds finder data.

I have to disagree with the negative comments about Wyoming and the sheep hunting there. Sheep hunting is more than tough and just as was stated by another member by the time one draws a tag you are probably in the later stages of your life. Ram horns have to be plugged by the G&F after the kill, so the stats showing the high kill percentage are exact, not a guess. Given the high kill rate you can rest assured that the sheep are there, but you can't do a five day hunt for one like for antelope and get one without an awful lot of luck.

In 2012 there were 8 tags and 6 sheep killed in unit 10. For 75% 2 Non residents, and 6 residents. 1 non-res and my uncle did not kill rams. He hunted the majority of the season. 2011 was almost a repeat of 2012. Everyone that drew a tag hunted both years.

He hunts the same area for elk every year, and has taken moose there every time he has drawn. My family has been hunting in that area since the 1960s. Including my uncle, who has probably killed 30 plus elk in that area.

They have horses, they know that area.

2016 was the last year for harvest data off that unit. Only 5 people hunted, 3 got rams pretty low odds there too. The 2 non-residents got rams, for the same unit. Years prior and had been more successful except my uncles year.

It looks like they had more sheep killed by lions or wolves than they realized, but still sold my uncle a license. A license he had used 19 points to get.

He saw no mature rams, and hunted the entire season.

An overview of all the Wyoming tags offered for sheep area 10, shows no real change, they have given out 8 tags for the past 5 years. Seems kind of like a let-it roll management philosophy to me.

I can tell you that a an area of 391 square miles, and a fairly isolated group of sheep ought to rest out. Or maybe they should kill everything since that had a recent pneumonia outbreak and let the place rest for a few years. Before they move sheep in from another area.

He did a lot of home work, and hunted an area he has known his entire life.

Wyoming sells a lot of tags, the most tags of any state outside of Alaska. They do not have any more sheep than Nevada or Montana, but they sell more tags. I have always believed they manage sheep like they are whitetails and that is the problem.

BGWyoming,

I'm not sure your comments have much relevance in regards to the research being discussed....