Deer herd for property size

[HottyToddy]

Hi all,

What would you expect a "healthy" herd to look like in the central Tennessee area on a 350-400 acre parcel? I'll be putting cams up, and I want to know what you'd like to see in terms of does, fawns, young bucks, and old bucks. Just trying to put together a harvest plan so I don't over/under harvest.

Thanks

 

[BSK]

HottyToddy,

That's a difficult answer to give, especially on smaller properties. herd dynamics (fawn recruitment, sex ratio, etc.) not so hard, but population can be very unique to each property. The problem is seasonal range-shifting. In some situations, deer do a lot of seasonal range-shifting throughout the year. In essence within their annual range, they may spend all of the winter in only a portion of that range. Then in summer switch to a different part of the annual range. Then in fall another section. What happens on smaller properties is that individual deer and social groups of deer may spend a lot of time on that property during one season, but not another. This can produce WILDY different deer populations throughout the year. This also means giving you an "appropriate" deer number is almost impossible. The only way to know if you have "too many" deer is to look at the food resources. Are deer eating away the best-quality food sources? THAT will tell you if you have too many deer.

But as for herd dynamics, after years and years of working with different herds, I prefer to see an adult (fawns not included) sex ratio of around 1.5 does per buck (make sure fawns are not included in the doe numbers - something that is hard to do later in the deer season). As for fawn recruitment (fawns per doe), the higher the better, but in many parts of the Southeast, fawn recruitment has been falling for the last decade or so. Don't be shocked if it is 3-5 fawns for every 10 adult does. 10 fawns to 10 does would be great, but few places see that level of fawn survival anymore. When it comes to buck age structure, a very healthy buck population will be 25% 3 1/2 year-old and older bucks. In essence, 1 in every 4 bucks is 3 1/2 or older.

 

[HottyToddy]

HottyToddy,

That's a difficult answer to give, especially on smaller properties. herd dynamics (fawn recruitment, sex ratio, etc.) not so hard, but population can be very unique to each property. The problem is seasonal range-shifting. In some situations, deer do a lot of seasonal range-shifting throughout the year. In essence within their annual range, they may spend all of the winter in only a portion of that range. Then in summer switch to a different part of the annual range. Then in fall another section. What happens on smaller properties is that individual deer and social groups of deer may spend a lot of time on that property during one season, but not another. This can produce WILDY different deer populations throughout the year. This also means giving you an "appropriate" deer number is almost impossible. The only way to know if you have "too many" deer is to look at the food resources. Are deer eating away the best-quality food sources? THAT will tell you if you have too many deer.

But as for herd dynamics, after years and years of working with different herds, I prefer to see an adult (fawns not included) sex ratio of around 1.5 does per buck (make sure fawns are not included in the doe numbers - something that is hard to do later in the deer season). As for fawn recruitment (fawns per doe), the higher the better, but in many parts of the Southeast, fawn recruitment has been falling for the last decade or so. Don't be shocked if it is 3-5 fawns for every 10 adult does. 10 fawns to 10 does would be great, but few places see that level of fawn survival anymore. When it comes to buck age structure, a very healthy buck population will be 25% 3 1/2 year-old and older bucks. In essence, 1 in every 4 bucks is 3 1/2 or older.

I really appreciate the response. I figured a property that small is hard to get an accurate guess, but I thought I'd ask. I appreciate the rough ratios to look at, as well as the tip to just watch food sources to evaluate your population. Thanks again!

 

[TheLBLman]

I figured a property that small is hard to get an accurate guess

One major issue is that 400 acres or less is typically only a minority of the acreage being utilized by those deer. During the rut, a particular buck using that 400 acres may actually be spending 90% of his time elsewhere.

In my experiences, about all you could typically plan on as being a sustainable harvest goal with that acreage might be one 3 1/2 or older buck annually, along with one or two does, and maybe one younger buck. Reality varies greatly, largely dependent on what's happening on the neighboring properties.

For example, if there were four 400-acre farms comprising 1600 acres in an area, it's possible 4 older bucks could be taken annually from that 1600 acres. But you may have one avid hunter & his buddies killing all 4 annually on one farm. This could be you and your buddies, or the reason you struggle to kill even one annually if a neighboring property is killing more than their particular acreage supports.

 

[Thelonegoose]

BSK and LBL are spot on. Our place is 350 acres and we have around a 2:1 doe to buck ratio. We harvest 4-8 deer annually. That usually consists of 2-3 2.5 to 3.5 year-old bucks and the rest does. I cannot speak about much of our neighbors' harvesting but I know they kill a few every year as well. I also think habitat diversity can play a big role in holding deer on just your land. Our is rolling hills with several water sources throughout with very different habitat types throughout the property. I have many deer that seem to never leave our place throughout the year (the rut may be the only exception).

 

[BSK]

HottyToddy,

When it comes to monitoring the deer population on your property, because of the highly variable nature of seasonal deer movements on smaller properties, the exact numbers aren't as important as evaluating the trends over time. And by that, I mean watching the numbers from year to year. Are the numbers going up? Down? Staying the same? What you want to know is if the population is increasing, decreasing or staying stable. Below is an example. This is the deer population on my own property over the last 20 years, determined through annual season-long non-baited camera censuses.

 

[DoubleRidge]

HottyToddy,

When it comes to monitoring the deer population on your property, because of the highly variable nature of seasonal deer movements on smaller properties, the exact numbers aren't as important as evaluating the trends over time. And by that, I mean watching the numbers from year to year. Are the numbers going up? Down? Staying the same? What you want to know is if the population is increasing, decreasing or staying stable. Below is an example. This is the deer population on my own property over the last 20 years, determined through annual season-long non-baited camera censuses.

BSK....Interesting data.....and I'm sure you have explained before but can you share the method used for a "non-baited" camera census?

I've read the QDMA recommendation or instructions for a baited 14 day census but I'm curious about your method for a annual season long camera census.

Between aflatoxin and possibly in the future CWD (sadly) I have no desire to pour corn out for a census but would like to keep better records from year to year.

 

[BSK]

I stopped running late-summer baited censuses for a number of reasons:

1) Pouring corn on the ground during the hot, humid month of August is a very bad idea. I've seen data from corn piles in I believe it was North Carolina that the Game Department tested, and a shockingly high percentage were infected with enough aflatoxin to kill every bird that ate from the pile.

2) I found very mixed results from corn piles in August. In areas where food resources at that time of year were very limited, corn pile censuses worked great. Yet in areas where food sources in August were good, older bucks would not come to the corn piles hence were not getting photographed. Seeing what I believed was 'corn pile avoidance," I ran a study on a property where I ran two baited censuses at the same time, one using corn and the other using salt licks. I purposefully placed some salt lick bait sites far from the corn bait sites and some very nearby. What I found was I was getting plenty of older bucks at salt lick sites, but very few at the corn sites. In fact, most of the older bucks I got on camera at the corn sites were just bucks passing through in the background. I suspect the older bucks were displaying corn-pile avoidance because the prevalence of baiting during hunting season. Older bucks have learned to avoid bait-piles.

3) I stopped using salt licks for baited camera sites because nothing transmits CWD faster than a salt lick. Instead of killing the infectious vector like salt does with bacteria and viruses, the high saline environment of a salt lick actually strengthens a prion.

4) This is the most important: I began to question the value of a late-summer census. In some areas, deer do little seasonal range-shifting. But in other areas deer do a LOT of seasonal range-shifting. In that situation, the deer you are censusing in August may not be the deer that are using the property during the hunting season, hence the value of the data collected is low.

 

[BSK]

A season-long non-baited census is run by simply setting up cameras in areas that naturally funnel deer movement, instead of using bait to draw the deer in front of the camera. And obviously by the name, it is run all season long instead of for only a brief period like a pre-season baited census is.

This process provides the benefit of seeing what deer are using the property during the actual deer season, instead of who is there only in the preseason. It also can provide a critically important window into when deer move on and off the property during the fall months and especially the 6-week peak breeding period. A smaller property can see a huge influx of "new" bucks during that 6-week window, whether through rut range-expansion or actual rut range-shifts (some bucks have a completely different range for the rut). A preseason census would catch few if any of those bucks. I have seen this play out to shockingly extreme levels on individual properties.

The downsides to this process are:

1) It requires more cameras to get good data. I find I need about 1 camera for every 80 acres to get good numbers.

2) Considerable knowledge of the property and the deer movement patterns are required for good camera placement that will generate quality data (or at least knowledge of common movement patterns for that property's habitat and terrain type).

3) These types of censuses generate a considerable amount of data that must be reviewed and cataloged (generally, 3-4 months of data).

4) Care must be taken when cataloging data to record the type of camera set-up used to collect each set of pictures because different set-ups will produce different trends in data. For example, cameras pointed into food plots will generate excellent fawn recruitment data, but sometimes very skewed adult sex ratio data. It's not uncommon for does to sit in food plots all day long while bucks tend to avoid them, producing adult sex ratio data that is highly skewed towards females. In contrast, cameras placed over scrapes will collect data highly skewed towards bucks. For this reason, when I review sex ratio data, I graph each type of camera set-up separately to see the differences between them.

But again, in a non-baited census, cameras are placed to overlook anything that might focus deer movement down to a small area. That can be deer trails, old abandoned log-skidder roads, holes in fences, low spots in fences, habitat edges, habitat bottlenecks, converging preferred terrain features, saddles in ridges, scrapes, food plots, and one of my favorites, the combined scrape on the edge of a food plot (I like to point the camera across the scrape and out into the food plot).

 

[DoubleRidge]

A season-long non-baited census is run by simply setting up cameras in areas that naturally funnel deer movement, instead of using bait to draw the deer in front of the camera. And obviously by the name, it is run all season long instead of for only a brief period like a pre-season baited census is.

This process provides the benefit of seeing what deer are using the property during the actual deer season, instead of who is there only in the preseason. It also can provide a critically important window into when deer move on and off the property during the fall months and especially the 6-week peak breeding period. A smaller property can see a huge influx of "new" bucks during that 6-week window, whether through rut range-expansion or actual rut range-shifts (some bucks have a completely different range for the rut). A preseason census would catch few if any of those bucks. I have seen this play out to shockingly extreme levels on individual properties.

The downsides to this process are:

1) It requires more cameras to get good data. I find I need about 1 camera for every 80 acres to get good numbers.

2) Considerable knowledge of the property and the deer movement patterns are required for good camera placement that will generate quality data (or at least knowledge of common movement patterns for that property's habitat and terrain type).

3) These types of censuses generate a considerable amount of data that must be reviewed and cataloged (generally, 3-4 months of data).

4) Care must be taken when cataloging data to record the type of camera set-up used to collect each set of pictures because different set-ups will produce different trends in data. For example, cameras pointed into food plots will generate excellent fawn recruitment data, but sometimes very skewed adult sex ratio data. It's not uncommon for does to sit in food plots all day long while bucks tend to avoid them, producing adult sex ratio data that is highly skewed towards females. In contrast, cameras placed over scrapes will collect data highly skewed towards bucks. For this reason, when I review sex ratio data, I graph each type of camera set-up separately to see the differences between them.

But again, in a non-baited census, cameras are placed to overlook anything that might focus deer movement down to a small area. That can be deer trails, old abandoned log-skidder roads, holes in fences, low spots in fences, habitat edges, habitat bottlenecks, converging preferred terrain features, saddles in ridges, scrapes, food plots, and one of my favorites, the combined scrape on the edge of a food plot (I like to point the camera across the scrape and out into the food plot).

Thanks for the explanation....makes sense....one more question.....what method do you use to extrapolate the data in your graph from thousands of pictures and videos? Do you use your adult buck to doe ratio then calculate your numbers based off of known unique bucks? Or?

 

[tellico4x4]

Brian,

Do you use the same formulas when doing the calculations on a season long survey as done on a baited two week one?

We stopped putting out minerals this year due to CWD concerns and alot of clover went dormant early so not getting the pics we normally do on summer plots.

Reimplemented observation log last season and percentages on it were close to the previous summer survey.

I have always used the survey data to determine how many does we kill each year but have been wondering how to proceed with above changes...
One of our rules is that a hunter has to kill as many does as they do bucks each season. Depending on survey, I have the option to require additional does killed if needed. If they don't then then they can't kill a buck the following season until their doe shortfall is fulfilled. Using this process we've been able to maintain a 1: 1.5 buck to doe ratio for past 16 years.

In order to reduce traffic on land during hunting season, we don't run any cameras on plots after bow opener and any cams in woods can only be checked when hunting a nearby stand.

Due to amount of plots we have versus neighbors, most of our deer are home bodies. Very often we kill mature bucks in November & December in same place they were all summer. Do see some transition but it is really minimal.

Have been wondering about just using observation data to make this years decision.

 

[HottyToddy]

Thank you all. This is all excellent information I haven't thought much on. Keep it coming!

 

[BSK]

Thanks for the explanation....makes sense....one more question.....what method do you use to extrapolate the data in your graph from thousands of pictures and videos? Do you use your adult buck to doe ratio then calculate your numbers based off of known unique bucks? Or?

Just remember that the only REAL number you get is the number of unique bucks. Everything else is a calculation. And those calculations are based on the assumption that all deer are repeat photographed as often as bucks are. maybe that's true and maybe it isn't. And that's why I say "watch the trends," not the actual numbers. Even if does and/or fawns AREN'T repeat photographed at the same rate as bucks, at least the trends will still be accurate. And of course, keep a close eye on where each set of data comes from. I produce a "final" number that is an average of all types of camera set-ups, but I also track the data for each camera set-up type separately to see if there are major differences.

Although the formulas are quite simple, all they are doing is using the average repeat-photograph rate of bucks to calculate the number of adult does and fawns. For example, if bucks are repeat photographed, on average, 20 times each, then the formulas make the assumption that each doe is repeat photographed 20 times and each fawn is repeat photographed 20 times.

TD = Total number of Does in all photographs
TF = Total number of Fawns in all photographs
TB = Total number of Bucks in all photographs
UB = the number of Unique Bucks represented in all buck photographs

UB = Actual number of bucks in the population
TD/(TB/UB) = Calculated number of does in the population
TF/(TB/UB) = Calculated number of fawns in the population

Add those three up to get the total population

(TF/TD)*100 = Fawn Recruitment Rate
(TD/TB) = Adult sex ratio (does per buck)

 

[BSK]

The below graph is one of the reasons I say, "Keep a close eye on where the data is coming from." This graph from my place is a representation of the calculated Adult Sex Ratio based on the type of camera set-up, and includes the four most common set-ups I use. It also includes the "average" of all set-ups (I have many, many types of set-ups, but the four graphed are the most common). The yellow line is the average of all set-ups. Notice how three of the four unique set-up data lines show very little change over time, yet the line for food plot set-ups (green line) has been sky-rocketing over time. I'm truly at a loss to explain this. No other set-ups show this trend. So if the sex ratio really isn't changing much - and the average suggests this is the case - why are does going to food plots and getting photographed so many more times while bucks are not? And this hasn't been a sudden change but a continuously increasing trend over a fairly long period of time.

I realize does spend a lot more time in food plots than bucks, and it would be normal to have sex ratio calculations from food plots skewed towards females, but why is this trend increasing so dramatically?

 

[DoubleRidge]

Just remember that the only REAL number you get is the number of unique bucks. Everything else is a calculation. And those calculations are based on the assumption that all deer are repeat photographed as often as bucks are. maybe that's true and maybe it isn't. And that's why I say "watch the trends," not the actual numbers. Even if does and/or fawns AREN'T repeat photographed at the same rate as bucks, at least the trends will still be accurate. And of course, keep a close eye on where each set of data comes from. I produce a "final" number that is an average of all types of camera set-ups, but I also track the data for each camera set-up type separately to see if there are major differences.

Although the formulas are quite simple, all they are doing is using the average repeat-photograph rate of bucks to calculate the number of adult does and fawns. For example, if bucks are repeat photographed, on average, 20 times each, then the formulas make the assumption that each doe is repeat photographed 20 times and each fawn is repeat photographed 20 times.

TD = Total number of Does in all photographs
TF = Total number of Fawns in all photographs
TB = Total number of Bucks in all photographs
UB = the number of Unique Bucks represented in all buck photographs

UB = Actual number of bucks in the population
TD/(TB/UB) = Calculated number of does in the population
TF/(TB/UB) = Calculated number of fawns in the population

Add those three up to get the total population

(TF/TD)*100 = Fawn Recruitment Rate
(TD/TB) = Adult sex ratio (does per buck)

Thank you! Exactly what I was looking for!.... appreciate the explanation!

 

[DoubleRidge]

The below graph is one of the reasons I say, "Keep a close eye on where the data is coming from." This graph is a representation of the calculated Adult Sex Ratio based on the type of camera set-up, and includes the four most common set-ups I use. It also includes the "average" of all set-ups (I have many, many types of set-ups, but the four graphed are the most common). The yellow line is the average of all set-ups. Notice how three of the four unique set-up data lines show very little change over time, yet the line for food plot set-ups (green line) has been sky-rocketing over time. I'm truly at a loss to explain this. No other set-ups show this trend. So if the sex ratio really isn't changing much - and the average suggests this is the case - why are does going to food plots and getting photographed so many more times while bucks are not? And this hasn't been a sudden change but a continuously increasing trend over a fairly long period of time.

I realize does spend a lot more time in food plots than bucks, and it would be normal to have sex ratio calculations from food plots skewed towards females, but why is this trend increasing so dramatically?

Wow....the food plot trend is dramatic. How did the food plots change over this time period? Increase in plot quality? Increase in plot size?....I'm sure the quality of the camera you use on the plots, with long range flash, has improved over the years.....I'm not sure if any of this explains anything? Just thinking out loud.

 

[BSK]

Have been wondering about just using observation data to make this years decision.

Tellico4x4,

For years I always said observation data was NOT very good for tracking actual changes in local population. And that was because, year to year, observation data didn't match actual numbers generated from photo censuses. The observation data would show wild swings from year to year while the population didn't change much. However, while playing around with some data I found that by using some simple statistical techniques intended to "smooth out" highly variable data from year to year, observation data suddenly showed a very strong match to actual population data. This statistical process is called a "Running Mean." And a running mean can be for any number of years (although it graphs out best if it is an odd number of years, such as a 3-year or 5-year running mean). In a 3-year running mean, each year's data point is the average of that year, the year before and the year after. Basically a 3-year span. A 5-year mean would be the average for that year, the two years before and the two years after. So in a 3-year running mean, the data point for 2019 would be the average of the three years 2018-20. The 2020 data point would be the average of the years 2019-21, etc.

The below graph is an example of how observation rates track population once both data sets are graphed as running means. This graph tracks the population of older bucks (2 1/2+) picked up by photo census during the month of November versus hunter observation rates of older bucks during the month of November. And again, both data sets are 3-year running means. The match isn't perfect, but pretty darn close. I would have no problem using that running mean observation data to make management decisions.

 

[BSK]

Wow....the food plot trend is dramatic. How did the food plots change over this time period? Increase in plot quality? Increase in plot size?....I'm sure the quality of the camera you use on the plots, with long range flash, has improved over the years.....I'm not sure if any of this explains anything? Just thinking out loud.

I promise you, I'm having all those same thoughts.

 

[Snake]

These guys have forgot more than most of us do know but when first looking at property without any data and there are no cattle on the property I look at the browse lines. Don't know if I spelled that correctly but if you have alot of deer you can see the browse lines pretty clearly if you can't tell then probably not over populated . Trail cams and boots on the ground is the best tools to get a handle on your density plus log sightings while hunting ( everyone). There will be times sightings will be more than usual then less simply because of variables out of our control . Bedding and food sources are keys and actually they really don't have to exist on your property but your property needs to be the funnel going to and fro to both . Once the gun hunting starts them all bets are off until rut time . Hopefully you have what deer like or must have on your property. Hope it's a good place .

 

[BSK]

These guys have forgot more than most of us do know but when first looking at property without any data and there are no cattle on the property I look at the browse lines. Don't know if I spelled that correctly but if you have alot of deer you can see the browse lines pretty clearly if you can't tell then probably not over populated .

Exactly Snake. How heavy the browsing is of food sources is THE BEST indicator of over/under population.