I'm sure someone on here has seen a study on the natural mortality rate of bucks. If you have a link can you please post it or if you'd like to discuss it let's hear it. I would expect each property to be different. I have one small farm we hunt that it seems very hard to get them to live above 3.5. We can pass them up and just watch them but we lose a lot of 3 year olds on that farm after the season is over. I found every possible shooter deer going into this season dead shed hunting. There may have been some foul play but there is no way to tell; I honestly think they died from infections late winter. The 3 year olds seem to be the hardest on their bodies during the rut so it makes sense in my head that they would have a higher mortality rate.
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Natural mortality rates
- Thread starter Dumbluck
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BSK
Well-Known Member
Problem is, radio/GPS collar studies with mortality sensors find VERY different numbers from place to place. Like you stated, I think buck natural mortality rates (death other than by hunters) is very site specific. My gut feeling is that mortality is VERY high for yearling bucks (they are stupid and feeling their first rut, getting themselves into all sorts of trouble), falls dramatically for 2-4 year-olds, then increases rapidly for 5+ year-olds. This is especially true in rugged hardwood terrain. Chasing does through the hills is very stressful, and high-quality food resources limited in those areas, producing extremely high post-rut mortality for bucks 5+ years old. Farm country is a different story.
Any data on what CWD is doing to buck mortality rates, other than if they get it, they die?
BSK
Well-Known Member
Haven't seen any good data on that, although I'm sure someone has done those studies.
That's what I have experienced on different Farms as well. Farmland deer with good habitat seem to survive better than woodland properties. I have one woodland farm that I would speculate that the survival rate past 3 years old is only around 10% without hunter intervention. I seem to lose a tremendous amount of 3 year olds after the season. I think it has a lot to do with the 3 year old bucks in that area rut extremely hard and fight each other creating injuries that turn into infections. I have killed a bunch of bucks over the years on that farm with swollen foreheads and puss coming out from fighting.
BSK
Well-Known Member
I've seen bucks make it to 8 1/2 in farm country. I've never seen a buck make it past 6 1/2 in ridge-and-hollow hardwoods.
BSK
Well-Known Member
Worked on a 1,000-acre high-fence in TN. Bucks had to be 4 1/2 before they could be shot. This lead to a lot of bucks making it to maturity. Terrain and habitat were rolling hills, about 60% hardwoods, and the rest pasture, agriculture, and tall grasses. Yet they could hardly ever get a buck past 6 1/2. Why? The high number of mature bucks in an enclosed environment lead to a blood-bath of fighting. Every year, post-season, we would have to go around and find all the mature bucks that had been killed by other bucks. It was a shockingly high number.
I've heard the same. I know someone that hunted a high fence ranch. They had the buck to doe ratio at 1:1 and they said it was common to find bucks dead due to the fighting. So they took the ratio up to something like 1.2 or 1.4 to 1, and it helped their mortality rate. Not sure if that duplicates over to free range deer in most places, but in heavily managed areas I bet it happens.
I saw some tremendously old deer on an agricultural place I had, and it seemed much easier to get them to survive past 3. Those deer were homebodies for the most part, which made it excellent for trophy management. They would mill around in extremely thick cover during the day and venture out mostly at night. I would suspect that is why they had a good survival rate against the hunters around there.
The woodland properties the deer seem to travel farther exposing themselves to more hunters making it harder to get them to 3 and our target age of 4+, but even when we do get them past the season as a 3 year old I find a bunch of them dead shed hunting. We also seem to get EHD much worse on these properties, I'm assuming because the deer are drinking out of ponds, puddles, ect... where the ag deer had a running river and springs.
There are many variables but I find it fascinating how habitat directly seems to affect the mortality rates.
I also think about Texas, many places down there don't even shoot deer until they are 8 years old. Most of our deer here would have gone downhill for 2-3 years in many cases if they survived that long.
I've only seen 1 woodland deer live to 8 years old and he remained about the same size since he was about 5, and started getting just a hair smaller after 6. There have been very few deer I've watched over the years make it to 6 as a buck.
BSK
Well-Known Member
I'm only talking natural mortality, not mortality associated with hunting. Even without hunting, you wouldn't see many bucks older than 6 in ridge-and-hollow hardwoods. They simply don't survive the rigors of the rut.
Yes I completely agree with that. I wish hunters would realize just how few deer actually survive to 4+ without hunter intervention. There seems to be an overwhelming belief that if the deer don't get shot they will survive or many of them will survive and that's just not the case on many farms.
BSK
Well-Known Member
Exactly. It's that misconception you can "stockpile" older bucks. You really can't. Time and time again when I do a photo census of a new property (most in western Middle TN) I will find the buck age structure is very similar, and this is true even on very large properties with tightly controlled harvests of only mature bucks. You can produce more total bucks, which will give you a few more mature ones, but you can't produce a population with a high percentage of mature bucks.
AlabamaSwamper
Well-Known Member
They definitely seem to disappear from something other than hunting the older they get
Have you ever looked to see what the numbers might look like on these farms for survival past 3 years old?
I typically hear "we have X amount of young of bucks, if we pass them up we will have a bunch of mature deer in a year or two". I typically take their X number and multiply it by 10% and say no you I may have this many mature deer to hunt. So if it's 30 they may have 3+/-. The 10% may be high or it may be low but what I'm trying to persuade them to see is that many of them just die without hunter intervention.
I have a guy I talk to every year that says he wants to do trophy management but in the same sentence will say "we have 35 young bucks using the farm we can shoot a few of them". Then calls and ask where all the mature deer are every year.
I tell him if he really wants to do trophy management he can shoot ZERO deer under 3 or he will never have any actual mature deer consistently, he might have one or two here and there but they don't all live that long to begin with.
LenS
Well-Known Member
BSK, or any others, just out of curiosity what is it that would be the "official" cause of death for a western-middle TN buck after a particularly stressful mating season? I understand that the stress of the rut is what runs them down, but is it infection, malnutrition, pneumonia, or some other condition that actually kills them?
BSK
Well-Known Member
Stress and injury-induced illnesses. In essence, they are so worn down physically from the rut, or have suffered such severe injuries during the rut, they physically can't make it through the winter. They simply succumb to over-all poor condition late in the winter.
It is commonplace for mature bucks to lose 30% of their body weight during the 6 weeks of the rut. Imagine you weigh 200 lbs and in 6 weeks you run yourself ragged until you only weigh 140 lbs. What level of health would you be in? Perhaps not even survivable condition.
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BSK
Well-Known Member
When looking at wild deer populations in western Middle TN, the age structures keep coming out right around 50% yearlings, 25% 2 1/2s, 15% 3 1/2s and 10% 4 1/2+. Now on very large properties where bucks are not open to harvest until 4 1/2, I will see a smaller percentage of the total adult male population being yearlings. Say around 40%. That is because hunting mortality of the bucks under 4 1/2 is much lower, hence 2 1/2 and 3 1/2 year-old bucks make up a higher percentage of the pre-hunt population. But it's not a massive amount higher. Again, perhaps 10% more 2 1/2s and 3 1/2s in the pre-hunt population than on smaller properties that are more affected by surrounding hunting pressure.Have you ever looked to see what the numbers might look like on these farms for survival past 3 years old?
I typically hear "we have X amount of young of bucks, if we pass them up we will have a bunch of mature deer in a year or two". I typically take their X number and multiply it by 10% and say no you I may have this many mature deer to hunt. So if it's 30 they may have 3+/-. The 10% may be high or it may be low but what I'm trying to persuade them to see is that many of them just die without hunter intervention.
I have a guy I talk to every year that says he wants to do trophy management but in the same sentence will say "we have 35 young bucks using the farm we can shoot a few of them". Then calls and ask where all the mature deer are every year.
This is excellent information. I always appreciate the feedback.
I kind of have a question like LenS. I have heard that bucks with head injuries i.e. puncture wounds that get infected have a high mortality rate because the infection gets into their brain. I have no idea if that has merit or not.
I kind of have a question like LenS. I have heard that bucks with head injuries i.e. puncture wounds that get infected have a high mortality rate because the infection gets into their brain. I have no idea if that has merit or not.
BSK
Well-Known Member
Actually, one of the highest mortality rates for bucks is from broken skulls due to rubbing, sparring and fighting. Placing so much pressure on their antlers often cracks the skull plate near the antler pedicle. Bacteria then gets into this crack causing a brain abscess to form. These are quite common and quite lethal.