Deer Ecology 101

[mooch]

Continuing on.... A topic that rarely gets mentioned, is how stress can effect deer. I'm not talking stress like going to a job, paying bills.... Stress comes in many forms. Environmental stress can come from disturbance around them in physical form such as new construction, road work...

But, there are also types of stress such as drought, heat, cold and rain. All of these factors affect how and what deer do on a day-to-day basis. It has been shown that stress, of any kind, in small amounts over a long period is more damaging that a high amount of stress over a short period of time.

Temperature and food are probably the two most common types of stress. Extreme heat and cold are very hard on animals. We can go inside to get out of the elements, but deer have to live in it 24/7. Heat and cold cause a higher consumption of food and water. Water in the heat, food in the cold. Obviously water is needed in higher amounts in extreme heat to help keep the body cooled down. Food in the cold to generate heat through digestion and absorption of fats and nutrients.

Is there any trend related to this that shows ratio of males/females birthed each year? Maybe for "survival reason"? For instance - a dry year does might tend to drop more females than males, etc.

[LivinADream]

the breeding season is determined by the length of day (photoperiod). Cervids are "short day" breeders, meaning they have their breeding season once the days get shorter with less light. That's why you see different rut periods in different places (north to south) at different times of the year.

I have heard this alot, and while I agree to an extent, if this were 100% accurate, why wouldn't you see the same "rut" across the state, or nation even, in the same horizontal belt?(probably not the correct term). Ex. South East Texas jefferson/chambers county sees a very early rut, mid to late September. Why isn't it the same say 250 miles straight East or west? Shouldn't the length of day be the same?
Not arguing, just trying to understand.

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[Top Of Texas]

I have heard this alot, and while I agree to an extent, if this were 100% accurate, why wouldn't you see the same "rut" across the state, or nation even, in the same horizontal belt?(probably not the correct term). Ex. South East Texas jefferson/chambers county sees a very early rut, mid to late September. Why isn't it the same say 250 miles straight East or west? Shouldn't the length of day be the same?
Not arguing, just trying to understand.

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While the bucks testosterone levels are controlled by sunlight, as is estrus in doe, environmental conditions do impact when doe are receptive. The school of thought is that birth is timed to occur when habitat conditions are at the most optimal for fawn survival, thus estrus is timed in the fall to coincide with a period in the spring that the doe's body is telling it will be best chances for the fawn.

Since Texas has a wide variety of climates we also have a wide variety of peak rut dates.

Excellent idea for a thread Hawkpuppy.

[LivinADream]

While the bucks testosterone levels are controlled by sunlight, as is estrus in doe, environmental conditions do impact when doe are receptive. The school of thought is that birth is timed to occur when habitat conditions are at the most optimal for fawn survival, thus estrus is timed in the fall to coincide with a period in the spring that the doe's body is telling it will be best chances for the fawn.

Since Texas has a wide variety of climates we also have a wide variety of peak rut dates.

Excellent idea for a thread Hawkpuppy.

This makes alot of sense to me, but also pretty much disproves the length of day period

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[bukkskin]

or when me and my neighbor were watching some does 2 weeks ago walk around picking out hackberry leaves that were falling among hundreds of other types of leaves.

just curious.

thanks for the info...[/QUOTE]

They were eating Hackberry leaves over oak?

[Top Of Texas]

This makes alot of sense to me, but also pretty much disproves the length of day period

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No, actually it's part of it. Studies have shown that if you keep a buck in 12 hours of light and 12 hours of dark that he won't shed his velvet because testosterone levels don't rise.

[Top Of Texas]

Check this link out. The Quality Deer Mgt guys are putting out some good, spot-on info in an outstanding and understandable fashion.

https://www.qdma.com/triggers-whitetail-rut/

[em12]

Tagged- great thread thank you for the knowledge

[lovemylegacy]

I always wondered about the selective feeding patterns of deer. How they may concentrate on certain plants of the same type. I planted soybeans this past Spring, they would eat the whole plot, but you could tell they were eating mostly in just one area about 20 yds long. Yall have any ideas on this?

[LivinADream]

This explains my question very well.

In southern regions, breeding dates aren’t as cut-and-dry. The photoperiod change is less dramatic, the climate is less severe, and there is less need to breed “on time.” This may explain why the breeding window is wider, but it likely does not explain why published reports show peak breeding in October in east Texas, December in Arkansas, January in Mississippi and Alabama, February in the Florida panhandle, and October in southeast Georgia. All of these regions share a similar photoperiod, so there are clearly some other factors involved. According to Dr. Karl V. Miller of the University of Georgia, southern deer are still under the influence of photoperiod, but exact timing of the rut is more influenced by genetics and maternal factors, and the synchrony of the rut is more influenced by herd demographics. This means photoperiod controls the approximate season of breeding (fall or winter), but the deer herd’s genetics likely influence the exact timing of breeding. The synchrony or “tightness” of the rut is then governed by how well the herd is managed. Herds under QDM,*with balanced sex ratios and improved buck age structures, have “tighter” or more synchronous ruts, which leads to increased rutting behavior, competition for breeding, and enhanced hunting opportunities. Poorly managed herds with unbalanced sex ratios and young buck age structures generally lack these benefits. - See more at: https://www.qdma.com/triggers-whitet....x0Bcj5GU.dpuf

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[Blackmouth]

[QUOTE=bukkskin;11997519]or when me and my neighbor were watching some does 2 weeks ago walk around picking out hackberry leaves that were falling among hundreds of other types of leaves.



They were eating Hackberry leaves over oak?

Hackberry is much higher on the preference list compared to live oak. This is also information from the Kerr WMA which has some doubters which is understood. Their explanation on preference is that certain species show greater browsing pressure over other species even in low to moderate densities suggesting a higher preference.

[jshouse]

or when me and my neighbor were watching some does 2 weeks ago walk around picking out hackberry leaves that were falling among hundreds of other types of leaves.

just curious.

thanks for the info...

They were eating Hackberry leaves over oak?[/QUOTE]

I'm not a tree expert but me and him were talking after the morning hunt and he mentioned watching a bunch of does standing and watching big yellow leaves falling from the trees and running over and eating them as soon as they hit the ground, he said they were eating them like candy... I saw the same thing with a couple does I was watching. I'm pretty sure he said they were Hackberry leaves.

[Top Of Texas]

Is there any trend related to this that shows ratio of males/females birthed each year? Maybe for "survival reason"? For instance - a dry year does might tend to drop more females than males, etc.

Yes. But what the research has shown is that when range conditions are good the doe produce a higher percentage of female fawns (slight, but statistically significant in some studies), and 50/50 to more male fawns when conditions are poorer. In Texas, where our annual rainfall is either wet or dry (not many average years), the fawn production sex ratio evens out over the years. So from a mgt standpoint, we use 50/50 annually.

Cause, I think (over 20 yrs since I sat in class), is still being debated. That is, in good years, are doe egg cells more receptive to buck sperm cells carrying female genes, OR, do doe fawns require higher nutritional needs from the mother, visa-versa, do buck fawns have better survivability in poorer years.

Fun question to ponder, but doesn't really impact mgt decisions.

[Top Of Texas]

is there a term for animals that, for lack of a better term, "know" what food is best for them and what isn't? like when browsing they know which plants are most valuable and which aren't (weeds in a food plot)...or when me and my neighbor were watching some does 2 weeks ago walk around picking out hackberry leaves that were falling among hundreds of other types of leaves.

just curious.

thanks for the info...

Generally just refered to as selective feeders, but pretty much everything is a selective feeder. How they "know" is an interesting question, no term I'm aware of. Basically, God designed each critter for its own thing, they just know. For example, if you put a bunch of kids in a room with a bowl of Hershey bars and a bowl of brussel sprouts and tell them they can eat all of which ever they prefer, we all know which bowl will be empty first. No one had to teach them, they just know.

[Top Of Texas]

They were eating Hackberry leaves over oak?

I'm not a tree expert but me and him were talking after the morning hunt and he mentioned watching a bunch of does standing and watching big yellow leaves falling from the trees and running over and eating them as soon as they hit the ground, he said they were eating them like candy... I saw the same thing with a couple does I was watching. I'm pretty sure he said they were Hackberry leaves.[/QUOTE]

Hackberry is one of our best browse species across most of Texas. It's used as an indicator, or "key" plant. That is, the degree of use the plants show is an indicator of how well balanced the deer numbers are relative to the amount of quality food available.

This is very important from a mgt standpoint in many parts of TX. In general, If you see heavy use, doe harvest should be targeted to reduce population size. If you see low to moderate use, doe harvest should be set to maintain population status, or, rarely, to allow growth.