Natural mortality of bucks

Lets take a break from Covid deaths and talk about deer deaths. I wonder how many die of natural causes. Ive never really researched it or heard much about it. I would think it has been studied. Common sense, I think, would say that a place that stays real shot up would probably not have many get old enough to die off. A well managed place should have a lot more older bucks so it seems more would die off. Although, a REAL well managed place would be efficient and selective in their killing so that numbers were controlled by killing inferior bucks, at least by maturity, to keep them out of post mature age class. Of course, a tight sex ratio would cause more fighting which can be deadly. And then too many deer means not enough food, so once again, death. The factors go on and on I guess. I didn't think this through much so help me out, teach me.....

Tight sex ratio and increased fighting - this is not good thinking from here. Tight sex ratios will indeed cause fights among seemingly stupid over-focused males in their pursuit of procreation, no doubt about that. It's just the best way to handle it. Even if not so tight sex rations, the numbers play out and grow tighter after each estrus cycle. So fight now or fight later It's going to happen. The best way for a buck to come off the rut is as quickly as possible. The quicker the does can get covered, the better. That means the estrus stops flowing and so will the buck response.

Those there does will typically cycle again every 28 days if not impregnated. You want as few of those 28 day re-cycles as possible. Those there bucks will literally screw themselves into a very bad, weakened position if allowed to be in the hunt for female companionship months and months.

Hud, all good points for sure. Generally speaking tight sex ratios are almost always good. Exactly how you define "tight" would depend on each specific situation and the goals of the managers/hunters. Just to clarify for all, I wasn't suggesting any of my points were good or bad or right or wrong. I just threw a few out to get some ideas going.

This buck died last year on our lease. We think of old age. He still had a little velvet on his horns so we estimate he died in late September. We had him on cameras for 6 years and never saw him in person. There’s no way to get an exact age on him but he looked old 6 years ago so we say 10+.

That's a bummer. What a handsome deer.

Just curious but why is it a bummer? A buck that lived a long time, putting his genes into the gene pool and then dying of old age is nature. Someone still has his antlers. Just because a hunter didn't kill him instead of good old Mother Nature isn't something to bemoan. Feel free to disagree but sometimes I think we as hunters take our eye off the big picture.

I'd bet that less than 15% of bucks make 5.5 years of age, regardless of reason. Predation, auto accidents, incidental accidents (broken limbs/infections/caught in fences), snakebites, parasites-LOTS of deadly reasons out there as to why deer pass on.

That's some of the insight im curious about. I know the 15% number would vary greatly depending on the situation but agree lots of death going on for various reasons. Im sure there are lots of studies out there on this but I just haven't looked for them. We almost never kill deer under 5 on our very big place that has very good neighbors. We are pretty efficient at killing the mature bucks that we do have. Still just do not see a whole lot of post mature bucks, so I agree theres lots of ways a buck(or deer) can die. The wild is a rough place to live a long life.

Most bucks that survive hunters/predators/etc. die from tooth wear/tooth loss (similar to horses) - they can not longer chew the browse. Of course with the addition of protein that has helped on severe toothwear -

We had a buck the first year I got on our lease that we thought was around 3-4 years old at the time. We got trail camera pictures of him each year but saw him live rarely. Our neighbor took him a couple of years ago - we estimated his age at a minimum of 12 years old

A LOT. Mother nature (Anthrax) took out an estimated 300 deer on our place last year

had an old lady rancher that bottle raised a doe that lived to be 17 years old in her house pasture (no hunting allowed) ... so they can live a long time

12% of each age class per year die on average based on a study done at the King Ranch years ago.

YMMV based on supplemental feeding, antibiotic treatments, environmental variances, etc.

this study on the callaghan showed mortality increases significantly with age.
https://www.researchgate.net/public...rtality_of_Mature_Male_White-Tailed_Deer

Mortality increases with anybody's age! lol

actually it doesn't. With humans there is a higher rate of mortality with 1-2 year olds than 10 year olds for example. The study on the Callaghan showed an almost linear increase in mortality from 1 to 7. I wouldn't have thought mortality with 3 year olds would really be higher than 2 year olds.

the king ranch study showing a more constant 10-12% mortality rate due to sickness, injuries, post rut conditions, etc seems more plausible IMO

We find a buck dead every or every other year. The ages are all over the place.

And based on what I've read on the subject, I would bet the majority of those who make it to that age will eventually die of old age, which can be as much as 8-10 years old or more. I mean, short of the high-fenced places where deer live much like livestock, how often do you see or hear of a buck that old being taken by a hunter.

I don't believe there is much of a "Natural Mortality" on Bucks around here unless it is maybe a very large property that is not hunted.

Very interesting stuff. I haven't read the links yet, but that's the kind of studies I was curious about. Thanks Kyle.

Don, I assume you are saying that they are shot by hunters before they can die of other causes. I think that is likely the case on many poorly managed places(shot out).

I think there are a lot more older deer running around than most people believe. Just personal opinion but there is no way 95% of the pictures posted here are 3 to 5 year old deer.

I believe that for areas that are t hunted or at heavily managed, but I hunted for years with cameras out and we only killed 1 mature deer amongst heavy hunting pressure.

Leonardo, can you clarify that. Where did the 95 number come from? Are you saying that a lot of pics posted on here are older than 5? Im not judging your opinion, I just don't understand it.

I agree with this part - TPWD estimates there are currently up to 4 million whitetail deer in Texas. Each year an average of 550,000 are harvested by hunters - 55% bucks/45% does. So on any given year, 1/8 of the deer population is harvested by hunters, and the population estimates still continue to go up...even with other causes of death like old age, autos, predators, etc.

I think the mortality rate of fawns passes that of any age class until extreme old age. Compare apples to apples and the answer is still the same, mortality is high close to birth, once weaned it goes down considerably and steadily rises through post mature age. Applies to humans and other mammals pretty much the same with a small difference in sex to account for different behaviors

95 was just a made up number from a majority of game camera photos that people post.

Personal experience, I had a lease in Archer County, plenty of mature big deer on it and they would disappear for years. Had a specific 10pt we called Shorty, G2 on his left side was about one third the size of his other tines, very easy to identify. First two years we had pictures of this deer regularly and saw him a couple of times. After that he completely disappeared for 4 years. Not one photo or sighting of the buck. We had aged him at 3 to 4 years old our first year on the lease. On the 4th year he jumps into the feeder pen, hangs around all morning, and we never see him again.

If I do the math right, you say he was 3-4, saw him for 2 years, and then came back in the 4th absent year, making him 3+2+4 or 4+2+4, 9-10 years old? That would be pretty ancient-did he look that old?

This follows findings that for any given season, 90% of the harvest will occur during the first two weeks. It doesn't take deer very long to learn that so many are after them, which is why middle-of-the-week hunts are more productive later in the season.

This totally - of course fawn mortality is high - they are defenseless - once they get on their own and get age on them then the numbers run the same as humans - more 60 year olds humans die than 50 year olds. More 70 year olds die than 60 year olds. With humans It is called the mortality tables - ask any life insurance company - they pretty much know exactly how many (not who) will die each year

PS and before anyone says "yeah but deer get shot" - so do humans

just found this one... havne't read it yet.

https://www.researchgate.net/public...rtality_of_Mature_Male_White-Tailed_Deer

Kyle, pretty sure that's the same study that you posted earlier. I have a hard time going through those studies cause they can be so detailed. Lack of patience I guess. I skimmed through the first one you posted and it was hard to get much from it without really digging in. It didn't seem their sample size was that large but maybe I didn't understand it. It seems their main conclusion was that if you passed up middle aged bucks that would be ok cause a lot would live to maturity. I guess, but not sure, that they tried to say that after maturity they started dying pretty quick. If someone reads and understands that study(or others) im curious.

Honestly I don’t think there’s anyway there could be an accurate state wide number for mortality. Just way too many variables. Even something as basic as rainfall can cause huge swings in mortality rates year to year.

100% agree on all the many variables that contribute. My opening post starting the thread I said "factors go on and on." Not expecting any precise answers on this I just couldn't remember a thread about this so I threw it out to see whatever comments were out there. Lots of good comments so far.
Maybe to take some of the variable out just offer up what yall know first hand from your own experiences.
For instance- #1. We have real heavy hunting pressure on our place and our neighbors and its rare anything gets to 5 yo so I don't think there is much "natural" mortality at all.
For instance- #2. Our place and all our neighbors is highly managed so that there is lots of natural browse and we also feed heavily. We never shoot anything young unless its really inferior. Because of this we see lots of 5 and 6 yo and some older. We almost always find older bucks that have died but no way to quantify how many.
For instance- #3. We have a HF place and we fly it a lot and have tons of TC so we have a very good idea of exactly what we have got. We constantly look all over for dead deer and we have found that "such and such" percentage die of natural causes.
Just throwing out some food for thought.

We lose a few bucks each year during the acorn gorge. These are always 4-6 years olds for us. We have never lost a doe or or a young buck to acorns.

SS, is there a way to determine a death from acorn gorge if the body and stomach are gone from scavengers?

One interesting thing I have seen in the couple of bucks I have found dead on my place is the brow tines on the two 3-4yo bucks we have found have had a downward turn to them. First one was a 160” 11 with 9 inch brows that had a good bend around half to two-thirds of the way up. The other was a approx 100-110 inch 8 pt and it’s brows were smaller but still had a pronounced bend in them. Bend was always away from the body toward the nose. N=2 so “always” is a strong statement with such a small sample. The young buck we found this year had really just nubbins for brows so it was not easy to tell if his would have bent down.

Don’t know if this is a sign of stress toward the end of summer, or disease, or what...none of the bucks we have shot have had downward bent brow tines.

There are so many variables to go by.............some places few ever make it to maturity and die of natural causes........some places like big ranch country with light hunting pressure......more die of natural causes than are killed by hunters which would certainly apply to the Pitchfork IMO......

Yelp And management. If you aren’t on MLD and have limited tag numbers lots of smaller eights die very olddd

This nails it. If they make it past 5 years they have pasture smarts. then a mistake on their part means a trip to the processor. After about 10 years the age factor comes on pretty heavy as to their survival.

Think of LF deer months equal to human years, and then think of the human years back when we had to make it in the wild. There’s a reason not a lot of frontiersman and Indians made it past 60, especially the men.

Nature is tough. Finding an 80 yo frontiersman or Indian would be incredibly difficult. Similarly, finding a LF 7 yo buck is more difficult than finding a 7yo doe, but in a well managed place with stressors limited they can be found easier. Think of habitat and food management as civilization for deer, and the more you improve civilization will 1. Allow more deer to hang out together, and 2. Allow older deer than without similar civilization, just like cities or village back in the day.

This analogy is not consistent with HF deer. Even native genetics in a HF are just not a fair comparison to the stressor a LF deer will face (for the most part).