What to do about the ‘carry-over’

Another low harvest means deer will have to depend on stressed habitat

Unseasonably warm temperatures continued into December; in fact a new record high was set in the Baton Rouge area around the middle of the month.

I spoke with LDWF’s deer section and there was concern that it could be another low-harvest year, somewhat similar to 2014 which was one of the lowest ever recorded.

I participated in the annual WMA Thanksgiving hunt at Pearl River WMA. It was not a great turn-out on the area but the Stafford Clan harvested a doe and boar hog. I saw deer and pigs but no shots.

The temperature got hot pretty quick, so I cut my losses and headed in, as did other hunters.

Deer biologists also reported that, while the overall turn-out was not too bad, the harvest was well below average and hunter success was poor.

They pretty much blamed the unseasonably warm weather that made for a poor hunter effort. It’s not much fun hunting in a T-shirt, especially when the mosquitoes are biting.

So what does a low deer harvest mean? It means fewer deer harvested, which means these deer will have to be carried-over on the habitat until next season.

While most hunters like the idea of more deer, from a biological standpoint it is not so good, especially if the habitat cannot support them.

Habitat can support so many deer (“carrying capacity” is the management term), and when numbers increase above what the habitat will support, both the herd and habitat will suffer.

Desirable browse plants are eaten up and body growth, antler development and productivity of the deer are poor.

For example, assume that 1,000-acre tract will support and maintain one deer per 20 acres. This tract will support 50 deer, and deer growth is good during the spring and summer months.

Let’s assume that the 15 adult does in the herd produce 30 fawns. This means the pre-season hunting population is 80 deer.

To keep this herd at carrying capacity (one deer per 20 acres), 30 deer have to be harvested during the season.

But let’s assume poor weather conditions made for tough hunting, so only 10 deer were killed. Now the post-season population is 70 deer, which means there is now one deer per 14 acres.

Just these 20 deer are impacting close to half of this tract, eating up desirable deer plants during the time of year when nutritional needs of the deer are high.

Now, let’s assume the adult doe population produces another 30 fawns, which makes the total pre-season population 100 deer. Not only has the carrying capacity been dramatically exceeded, but it is probably impossible for the landowner to harvest 50 deer during the season in order to keep the population in balance with the habitat.

While many hunters like the idea of carry-over, it is not good for the habitat and the herd.

How does a landowner or club handle carry-over and offset the effects of it?

The abundant mast crop this year will help to some degree and provide nutrition for deer through the winter and early spring. The mild temperatures might also help to keep the native deer browse forage growing.

Certainly, forage plantings (aka food plots) with highly nutritional plants such as clover, chickory or winter peas will provide food during the spring growing season. Plantings of winter grass such as wheat or rye grass will not do much for the deer once they seed out.

It might also be a good idea to get on the tractor and get the ground ready for the summer crops a little earlier than normal so more supplemental forage will be available for the deer during the summer and early fall.

Timber cuts that were done in the fall will begin producing native browse plants, and this will help in the spring and summer. A little timber stand improvement work, such as thinning of undesirable tree species, will get more sunlight on the ground and start producing browse for the deer.

Desirable shrubs that might have grown out of the reach of deer can be cut knee-high and will start putting out new growth for deer.

It would probably be a good idea to get a biologist out to look at the spring habitat and see exactly what the browsing pressure is. While we do not have the starvation die-offs like they have up north, deer having to live on subpar habitat will not exhibit good body growth or antler development.

There is the possibility of die-offs from disease issues when density levels are high.

Carry-over might help increase some of the herds in Areas 4 and 9 where the either-sex seasons were reduced in an effort to increase numbers. However, it is generally best to keep the herd below carrying capacity to achieve maximum growth and antler development, because once carrying capacity is exceeded it can be a difficult task to get the numbers back in line with the habitat.

About David Moreland 245 Articles
David Moreland is a retired wildlife biologist with LDWF, having served as the State Deer Biologist for 13 years and as Chief of the Wildlife Division for three years. He and his wife Prudy live in rural East Feliciana Parish.