Alaska Winter Kill

Bambistew

WKR
Joined
Jan 5, 2013
Messages
391
Location
Alaska
As I alluded to earlier this year... In addition parts of the Alaska Range (South of Fairbanks) and the Brooks Range showed lower than expected populations; some units had the lowest numbers recorded in the last 15-20 years. Good luck, I think we might need it!

Aerial sheep surveys reflect hard winter in some areas

During the winter of 2019/2020, some portions of Alaska’s Dall Sheep range experienced deep, unstable, and persistent snowpack after an unusually hot, dry summer. A combination of factors such as these can result in higher than average winter mortality in sheep and may also contribute to lower than average lamb production the following spring.

ADF&G biologists monitor Dall sheep populations by conducting aerial surveys to determine minimum counts of sheep in established count areas in late June and July. These surveys are a snapshot in time and compared to years of previous data for the same count area provide a glimpse into population trends. This July, surveys are suggesting that the winter took a toll on some sheep populations. Sheep counts in portions of Unit 13 have dropped 25% to 35% when compared to previous surveys. Similar declines have been observed in the past, following severe winter conditions or persistent snowpack through the spring. In other areas where winter conditions were less severe sheep counts this July have not shown the same decline.

Radio collar data in the eastern Talkeetna Range in Unit 13A support the presumption that this year’s lower counts in that area reflect a hard winter. Collared ewes displayed roughly 50% mortality, with most mortalities attributed to avalanches and predation. Ram mortality was much lower in the same area, at roughly 5%. Managers in Palmer noted fewer ewes and lambs in the Unit 14A portion of the Western Talkeetna Mountains, however the ram segment of the population was largely unaffected. Ewe mortality in the Chugach range of 14C, however, was only about 7%, providing evidence that some areas were not as affected by winter mortality.

Lower counts often reflect natural fluctuations in sheep populations and legal rams are still available for harvest in most cases. However, it is important to note we are beginning to see the results of the hard winters and poor lamb crops of 2012/ 2013 working their way through the population which could also have an effect on ram availability. Due to these combination of factors, this fall hunters might expect to see fewer overall sheep in areas such as the eastern Talkeetna Range or portions of the Chugach range. For the latest information specific to your potential hunt area, contact your local ADF&G office.



Todd A. Rinaldi

Regional Management Coordinator



Alaska Dept of Fish and Game

Division of Wildlife Conservation

1801 South Margaret Way, Suite 4

Palmer, AK 99645
 
Joined
Apr 9, 2012
Messages
1,848
Location
Fishhook, Alaska
That matches expectations.

That letter is from the southcentral biologist, but the word we got from the interior guys was similar. I believe 20A in particular took a bad hit.

With the combination of high winter kill, and the follow on effects of 2012/13... it's going to be slim pickings in some drainages for a while.
 

wantj43

Lil-Rokslider
Joined
Aug 15, 2015
Messages
119
Thank you for posting the survey information.
However, before becoming too disheartened by the survey numbers it might be worth while to look at success rates and effort required and age structure of harvest following past periods of what appears to be higher than usual mortality rates.
Joe
 

wantj43

Lil-Rokslider
Joined
Aug 15, 2015
Messages
119
That matches expectations.

That letter is from the southcentral biologist, but the word we got from the interior guys was similar. I believe 20A in particular took a bad hit.

With the combination of high winter kill, and the follow on effects of 2012/13... it's going to be slim pickings in some drainages for a while.
Given there have been several periods where we have seen some dramatic reductions of sheep populations has the predicted change in the age structure of the harvest been demonstrated? Realizing there are some complicating factors such as reduced number of hunter usually after lower counts of sheep.
Joe
 

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chisana

FNG
Joined
Sep 24, 2016
Messages
44
Location
Juneau, Alaska
Given there have been several periods where we have seen some dramatic reductions of sheep populations has the predicted change in the age structure of the harvest been demonstrated? Realizing there are some complicating factors such as reduced number of hunter usually after lower counts of sheep.
Joe

Even after the die offs there have always been some old rams that made it through. We are hunting an area with low density to begin with this year and the area biologist reports about half the normal number sheep on the survey. Counting on one or two of those old rams that got through the winter!
 
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