Your Experiences hunting after a Hard Winter

[2rocky]

Curious what folks have noticed about deer herds the Season after a hard winter. Please mention specific years....

I've heard the big bucks can survive but fawns and does are the brunt of the winterkill.

For successful hunters was the trophy quality different?

 

[brymoore]

Does survive and fawns/old bucks die.

Last two bad winters in my state had 100% of fawns die one winter and 50% of fawns two winters later. Deer populations were good so no immediate noticeable loss. However, it became apparent a year class of bucks was gone from the fawn death.

The deer in my area did fine this year. Bad years you can count the dead fawns lying on the winter grounds as I drive.

 

[sclancy27]

After 2011, MT. We noticed mature buck numbers reduced as we got 3-5 or 6 years past the severe winter, correlates to a loss of fawn class. We also noticed that certain habitats did not winter kill like others...there were patches of good deer numbers. We killed a couple 7 and 8 year old bucks post winter.

After drought of 2021. Still patches of decent deer numbers, but effects of drought were much more homogenous than winter, reduction across age classes and habitats. Still saw mature deer, we killed 4-5 yr olds in 2021 and 2022.

The overall reduction was similar across both of those events, from over 100,000 animals in R7 to ~50,000 animals.

 

[HUNT JR]

I hunted region G in 2017 and had a pretty tough hunt. I did not really see any good bucks of age. I had been in there in 2015 and saw a lot of deer in the same area, in 2017 it was a ghost town.

 

[Irishman]

The winter of 96/97 was probably the worst for wildlife in NW Montana that I remember. Huge amounts of snow at the start of hunting season, resulted in a lot of deer being killed right of roads. The following year, it seemed that only small bucks survived. However, I read that it wasn't that only young bucks survived, but that their antler growth was reduced due to their physical condition after the long winter.

 

[nrpate05]

I don't really have any direct experience, but the idea of losing essentially an entire generation of animals is pretty fascinating to me. Like, if I draw a Region G deer tag in 4 years, there will literally be no 4 year old animals. I'm not sure why it is so fascinating, but just is to me. It makes me wonder how many deer are in each age class in each herd. It would put it into perspective about how many deer you are not seeing.

 

[Bambistew]

I don't know chit about chit, but read a lot about this kind of thing.

The idea of winterkill has been on my mind a lot, less so for deer, but I think most all animals see similar outcomes on varying scales. The one thing that deer have going for them is they will often raise twins to adulthood, compared to other animals that only have one fawn/calf/lamb.

The majority of fawns that survived spring/summer will perish in the winter, a higher proportion of yearlings will also die. A larger than normal amount of does and bucks will die, however they tend to have fairly high survival rates even in bad winters. Like 90-2% on average, but you may see survival around 80-85% from what I've read. Bucks tend to survive better than does, but the older bucks run down from the rut tend to have higher mortality than younger subordinate bucks on normal years, and more so in bad years. Those type of bucks make up a small part of the population so the loss is not that apparent in most cases. In addition, depending on the condition of the does going into into the winter, there may be a really low birth rate due to stress. In areas where you have 90-95% birthing rates you may see 50% or less, then 50% of those fawns survive to fall, and on a good year 60% might make winter.

On a normal year you may have 100 does going into fall, 92 survived to fawn. They drop drop (1.5) per doe or 140 fawns, 70 make it to fall, and about 42-45 of those make spring. I'm not a bio by any stretch, but I think you need about ~35% fawn survival to have a sustainable deer population.

After a bad winter, you have 80 does, 40 drop 60 fawns, 30 make it to fall, and 18-20 survive. It doesn't offset mortality of adults, and your population may decline the following year. Range conditions coming into winter will also effect the rebound. One bad winter can have a big effect for a long time, IMO.

In the end, one bad winter can largely effect 3 cohorts of the population, not just the fawns that died that winter, but also the spring fawns and a higher proportion of yearlings.

I've spent some time doing stochastic modeling of sheep populations here in AK. Having a data set with actual ages of harvest is really interesting to view. Also studies with survival rates, observed populations, etc. We can see increases and decreases in age classes as they line up with past winters in the harvest results.

Its very difficult to forecast this stuff on a micro scale. Some herds will fare better than others for a multitude of reasons, and they could be just 20 miles away.

Rebuilding herds takes a lot of things to line up as well. With "average" winters and mortality, you maybe skim some with hunting and still increase the population, but not what you previously did, obviously. If you have another below average winter, your population will continue to decline, even with reduced hunting.

I've looked at the sheep situation here... We need a lot of "easy" winters in the next 20 years to get us back up to where we were just 10 years ago. A lot is 50% or more easy winters in the next 20. They historically come around 20% of the time, so I highly doubt I will see the same populations I did 10 years ago. I know sheep are not deer, but hunting is not the limiting factor of the population. Winter is #1 followed by predators and avalanches.

As a proxy you could look at what happened in Colorado since the bad winter of 2007-08. CO has a lot of population and harvest information. The deer numbers in the Gunnison basin, for example, bounced back to winter die off 15 years ago, but the age class of bucks isn't there, IMO. They also adjusted the management plan and reduced the buck:doe ratios. I'm only an outside observer, but have followed the deer situation there since about 2000.

The hard thing is determining what constitutes a "hard" winter and the probable outcome, or if that was the only contributing factor to the population decline. Our sheep, moose and caribou populations have declined sharply from our bad winter of 2011-2012, and the bad winter we had last year, really crushed the rebuild. Locally, this winter is just as bad as 2011/12 and worse than last year.

 

[Ben Long]

The winter of 96/97 was probably the worst for wildlife in NW Montana that I remember. Huge amounts of snow at the start of hunting season, resulted in a lot of deer being killed right of roads. The following year, it seemed that only small bucks survived. However, I read that it wasn't that only young bucks survived, but that their antler growth was reduced due to their physical condition after the long winter.

THAT was a brutal winter. I can't account for antler size, but yeah lots of dead deer in the roads. If they didn't starve, they got hit by cars. I remember seeing more wolves and lions than usual the next year, but their numbers dropped subsequently. Rebound took 3-4 years.

 

[Bambistew]

The winter of 96/97 was probably the worst for wildlife in NW Montana that I remember. Huge amounts of snow at the start of hunting season, resulted in a lot of deer being killed right of roads. The following year, it seemed that only small bucks survived. However, I read that it wasn't that only young bucks survived, but that their antler growth was reduced due to their physical condition after the long winter.

I recall reading a study that linked antler size to the stress a doe was in during pregnancy. If they were stressed (during a bad winter) the buck fawn would never develop a large set of antlers. I don't recall how they determined if the buck would have had big antlers in the first place though.

 

[rogerthat]

There is also the flip side which is the habitat is typically underutilized and in better shape coming out of hard winters also. The silver lining of a hard winter if you may.

 

[RyGuy]

I don't know chit about chit, but read a lot about this kind of thing.

The idea of winterkill has been on my mind a lot, less so for deer, but I think most all animals see similar outcomes on varying scales. The one thing that deer have going for them is they will often raise twins to adulthood, compared to other animals that only have one fawn/calf/lamb.

The majority of fawns that survived spring/summer will perish in the winter, a higher proportion of yearlings will also die. A larger than normal amount of does and bucks will die, however they tend to have fairly high survival rates even in bad winters. Like 90-2% on average, but you may see survival around 80-85% from what I've read. Bucks tend to survive better than does, but the older bucks run down from the rut tend to have higher mortality than younger subordinate bucks on normal years, and more so in bad years. Those type of bucks make up a small part of the population so the loss is not that apparent in most cases. In addition, depending on the condition of the does going into into the winter, there may be a really low birth rate due to stress. In areas where you have 90-95% birthing rates you may see 50% or less, then 50% of those fawns survive to fall, and on a good year 60% might make winter.

On a normal year you may have 100 does going into fall, 92 survived to fawn. They drop drop (1.5) per doe or 140 fawns, 70 make it to fall, and about 42-45 of those make spring. I'm not a bio by any stretch, but I think you need about ~35% fawn survival to have a sustainable deer population.

After a bad winter, you have 80 does, 40 drop 60 fawns, 30 make it to fall, and 18-20 survive. It doesn't offset mortality of adults, and your population may decline the following year. Range conditions coming into winter will also effect the rebound. One bad winter can have a big effect for a long time, IMO.

In the end, one bad winter can largely effect 3 cohorts of the population, not just the fawns that died that winter, but also the spring fawns and a higher proportion of yearlings.

I've spent some time doing stochastic modeling of sheep populations here in AK. Having a data set with actual ages of harvest is really interesting to view. Also studies with survival rates, observed populations, etc. We can see increases and decreases in age classes as they line up with past winters in the harvest results.

Its very difficult to forecast this stuff on a micro scale. Some herds will fare better than others for a multitude of reasons, and they could be just 20 miles away.

Rebuilding herds takes a lot of things to line up as well. With "average" winters and mortality, you maybe skim some with hunting and still increase the population, but not what you previously did, obviously. If you have another below average winter, your population will continue to decline, even with reduced hunting.

I've looked at the sheep situation here... We need a lot of "easy" winters in the next 20 years to get us back up to where we were just 10 years ago. A lot is 50% or more easy winters in the next 20. They historically come around 20% of the time, so I highly doubt I will see the same populations I did 10 years ago. I know sheep are not deer, but hunting is not the limiting factor of the population. Winter is #1 followed by predators and avalanches.

As a proxy you could look at what happened in Colorado since the bad winter of 2007-08. CO has a lot of population and harvest information. The deer numbers in the Gunnison basin, for example, bounced back to winter die off 15 years ago, but the age class of bucks isn't there, IMO. They also adjusted the management plan and reduced the buck:doe ratios. I'm only an outside observer, but have followed the deer situation there since about 2000.

The hard thing is determining what constitutes a "hard" winter and the probable outcome, or if that was the only contributing factor to the population decline. Our sheep, moose and caribou populations have declined sharply from our bad winter of 2011-2012, and the bad winter we had last year, really crushed the rebuild. Locally, this winter is just as bad as 2011/12 and worse than last year.

I enjoyed reading this post. Very informative. I feel like you took a lot of information and condensed it down into a readable fashion

 

[appaloosa]

I have been through several of them, and the real bad winters are definitely noticable. The two most recent ones in '10/11 and '16/17 were pretty hard on our deer. One noticable difference to me are the group sizes. During the early season, bucks will often travel in bachelor groups. Group size can vary, but they can be pretty large, 10+ animals sometime. After the hard winters, the group sizes just seem to be smaller, instead of 5-6 or more bucks together, it is more like 2-3. This can obviously vary, but the general pattern tends to apply. The other obvious difference is the lack of yearling bucks. They are usually pretty abundant and tend to be more visible (i.e., up all day, sparring, etc). After bad winters, they are noticably reduced, or sometimes absent. Which is intuitive, of course, as many more fawns tend to perish during bad winters.

 

[antlerradar]

The winter of 96/97 was probably the worst for wildlife in NW Montana that I remember. Huge amounts of snow at the start of hunting season, resulted in a lot of deer being killed right of roads. The following year, it seemed that only small bucks survived. However, I read that it wasn't that only young bucks survived, but that their antler growth was reduced due to their physical condition after the long winter.

This has been my experience. A tough winter will knock 5 to 10% off of the next falls antlers.

 

[antlerradar]

I recall reading a study that linked antler size to the stress a doe was in during pregnancy. If they were stressed (during a bad winter) the buck fawn would never develop a large set of antlers. I don't recall how they determined if the buck would have had big antlers in the first place though.

There is also the flip side which is the habitat is typically underutilized and in better shape coming out of hard winters also. The silver lining of a hard winter if you may.

I think there there is something too this. Fawns born the spring after a tough winter likely have an up hill battle the rest of their life. Fawns born a year or two later likely benefit from lower competition. I do not think it is a coincidence that the best year for big deer I ever saw was 87. Right about the time the fawns born a few years after the extremely bad winter of 78/79 were hitting their prime.

 

[rogerthat]

I think there there is something too this. Fawns born the spring after a tough winter likely have an up hill battle the rest of there life. Fawns born a year or two later likely benefit from lower competition. I do not think it is a coincidence that the best year for big deer I ever saw was 87. Right about the time the fawns born a few years after the extremely bad winter of 78 were hitting their prime.

Yeah I have been trying to wrap my mind around that aspect as well. That makes a lot of sense

 

[HiMtnHntr]

I hunted a good area in WY in 2007 and again in 2008…. Night and day difference.

 

[squirrel]

Hard winters are hardest on: (in order)
fawns, many times 100% or might as well be. I have seen 4-5 winters where it was well over 90%. They are dumb (cars/trains) they are small (severe cold) and they are slow (predation). Here they almost never technically starve, they just get so weak they stand in the road and get smacked by a Subaru going 70. Or they jump a fence and miss and get twisted in the top two wires.

yearling bucks: they just dont have the body mass and strength to get to food and withstand the cold. Far fewer die on the roads though as they are a bit wiser

Ancient(10+ yrs) bucks/does: but with lead poisoning is it really a factor? Not in any measurable number, but it should be, and it would be nice to see.


Mature (as opposed to ancient) deer are amazingly tough, especially the burly dominant bucks that game depts claim drop like flies (so they may as well get shot) And highway/train death for big bucks is about zero. When the big bucks do winter kill they almost always drop their antlers first even if it is very early then they croak. Not a lot of 180+ dead heads available to pick up.

We have so few deer now due to hunting that it doesn't really matter what happens in the winters. 15 years ago we had more winter kill than we have show up on the winter range now, and still the printer keeps spitting out tags.

I have never noticed a severe reduction in score after hard winter amongst the mature bucks, but it is very easy to notice the missing age class after a 100% fawn kill. With last years fawns being next falls dominant breeders we may have to start a sperm bank locally. Two years from now we may have no burly 14" 3x3's strutting around like they own the sage.

One of the oldest deer I have ever seen in his last winter, and it was not all that harsh of a winter, but too many birthdays is a very fatal disease.

 

[MThuntr]

After 2011, MT. We noticed mature buck numbers reduced as we got 3-5 or 6 years past the severe winter, correlates to a loss of fawn class.

2011 was a messed up year for the antelope too. Some of the units in North Central Montana dropped significantly. I remember trains hitting like 1000 out of Glasgow.

 

[Schaaf]

I think there there is something too this. Fawns born the spring after a tough winter likely have an up hill battle the rest of their life. Fawns born a year or two later likely benefit from lower competition. I do not think it is a coincidence that the best year for big deer I ever saw was 87. Right about the time the fawns born a few years after the extremely bad winter of 78/79 were hitting their prime.

Study that Bambi's referring to.

 

[Schaaf]

2011 was a messed up year for the antelope too. Some of the units in North Central Montana dropped significantly. I remember trains hitting like 1000 out of Glasgow.

That winter had an even worse effect on pronghorn than it did deer north of the Missouri. We had a nearly 100% mortality on fawns and yearlings. I believe it was Andrew Jakes that had a study that pointed to nearly every surviving doe from that winter aborted the fetus but was unable to pass the femur bone of the fetus and became sterile for the rest of their life.

So you were left with repopulating an entire area with only the does and yearlings that were not bred going into that winter. It took at least 7-8 years to even see 50% of the pronghorn that used to be north of the river and Fort Peck.