Fetal Surveys Showing Deer Management Isn’t ‘One Size Fits All’

Heritage matters when it comes to managing large game animals like white-tailed deer, and Alabama’s deer herd can be best described as a patchwork of different genetic strains with a corresponding patchwork of rutting activity.

By David Rainer, Alabama DCNR

When whitetail numbers were low in the early 20th century, restocking efforts brought in deer from numerous sources to try to ensure the population would rebound. Rebound would be an understatement, with the number of deer in Alabama currently estimated at about 1.5 million animals.

However, the remnants of those restocking efforts remain. While many of the deer that were part of the restocking program came from southwest Alabama, animals were also brought in from Arkansas, Georgia, Michigan, North Carolina, Ohio, Texas and Wisconsin.

Deer in southern Alabama, south of Montgomery where this buck was killed, have breeding dates into March based on fetal conception surveys.

Deer in southern Alabama, south of Montgomery where this buck was killed, have breeding dates into March based on fetal conception surveys.

“Alabama has a bunch of different deer we have to deal with,” said Chuck Sykes, Director of the Alabama Wildlife and Freshwater Fisheries Division (WFF). “When I managed deer in Illinois, I managed one deer. If you manage deer in Alabama, you have a sack full. Depending on where you are is how you have to adapt your management strategies.”

For the first time, the Alabama Conservation Advisory Board and Conservation Commissioner N. Gunter Guy Jr. approved a shift in the deer season in southwest Alabama into February. That area (see map) will swap 10 days of hunting in December for hunting the first 10 days of February.

“Southwest Alabama is the place with the highest reliability of data that supports a late rut and the season shift,” said Sykes, a wildlife biologist in the private sector before becoming WFF Director in December. “That area was selected for a pilot project. Mississippi is doing the same thing in southeast Mississippi.

“With my professional background as a wildlife consultant and growing up in Choctaw County, one of the first things the Commissioner did was to give me this conception data that the staff has been working on and ask my opinion as to where the February season was justified by the data.”

The data was collected using a deer fetal study, which has been underway since 1995. Does are harvested and necropsies are conducted. The fetuses are measured and a conception date is determined by a standardized scale.

Alabama's deer season for 2013-14 will include this portion of the southwest corner of the state with dates into February for the first time. Fetal surveys in this area indicate breeding dates throughout February, after the traditional Jan. 31 closure, and state officials shifted season dates to coincide with breeding periods. (Graphic: Alabama DCNR)

Alabama’s deer season for 2013-14 will include this portion of the southwest corner of the state with dates into February for the first time. Fetal surveys in this area indicate breeding dates throughout February, after the traditional Jan. 31 closure, and state officials shifted season dates to coincide with breeding periods. (Graphic: Alabama DCNR)

Sykes and his staff looked at those areas south of U.S. highway 80, but the influence of a Georgia strain of deer in the areas east of Montgomery presented mixed results in the data. Therefore, the February shift was only proposed for southwest Alabama.

“I also got calls from people who knew I was from Choctaw County,” he said. “Most of Choctaw County is not in the new zone. Biologically speaking, from my experience Choctaw would fall into the zone, but my point to those who called was that we did not have the scientific evidence to prove it.

“So this year we targeted (for the fetal study) heavily the counties south of Highway 80.”

This year’s samples are being taken from 104 sites in 49 counties, the majority of those south of (U.S.) Highway 80. The ideal sample size is five deer per site with at least two sample sites per county. Additional sites were added along the Chattahoochee River for extra scrutiny. Sykes said that between 450 and 500 deer will be sampled this spring and summer.

“This is an extensive project,” he said. “Our guys are going out three and four nights a week to try and get this done. We’ve got biologists, biologist aides, volunteers and some law enforcement officers helping to get the samples. We had some private individuals donate their property but also take some of the deer for us. Those individuals put the deer in their coolers, and all our biologist had to do was go down and perform the necropsies. So normally what would have taken us an average of 16 hours, our biologist was able to collect the data in three hours.”

Sykes said the preliminary data so far suggests that the anecdotal data is pretty much lining up with the scientific data in most of the sample sites. One such site belonged to Commissioner Guy.

“I haven’t been surprised, and most of the landowners haven’t been surprised,” Sykes said. “When we sampled the Commissioner’s place, I asked him when his deer rutted and he told me. After we finished, the data supported it.”

“We sampled a site in Marengo County, and when we were hanging the deer up, I asked the landowner what he thought. He said, ‘We really don’t need the 10 days in February on my place.’ The bulk of the does collected on his place were bred on the 18th and 19th of January. The latest conception date I have seen this year is March 10 in Monroe County.”

Sykes said there could be several reasons for a late conception date.

“You want a window of a couple of weeks for the majority of the primary rut to occur,” he said. “Proper habitat and herd management will ensure that this takes place. You’re always going to have a smaller secondary rut even when the herd is healthy and the buck-to-doe ratio and age structure are right. When you start to have a skewed buck-to-doe ratio, that’s when you start having a real strong second and even third rut.”

“I learned this while I was going to school when we put one buck and one doe in an enclosure at the deer facility at Auburn. Earlier studies suggest those deer should come into estrus in November or December. No, an Alabama doe is going to come in when she is genetically programmed to do so. If there is one buck for her, she’s going to be bred around the last week of January. But if there are 10 does to one buck, it might be February or maybe March before she gets bred.”

Sykes also said there a misconception about the number of does a single buck is able to breed during one estrus cycle.

“When a doe starts to come in, that buck is going to tend her,” he said. “He’s going to go with her wherever she goes until she is ready to breed, which may be two or three days later. While that’s happening, he may miss two or three more. It’s a numbers game.”

“Some people are saying they’re going to save a buck to do most of their breeding for next year. But most studies show that a buck is only siring two to three fawns per year if they’re lucky.”

Sykes said the preliminary data indicates that the people who requested a February season to be able to hunt the rut appear to have a valid point.

“What I’m hoping is this will be validation for the zone that was selected this year, and it may provide pretty good evidence that it could be expanded,” he said. “I completely support what the commissioner and Conservation Advisory Board did this year. This is a big step. I’d rather start small and work our way up when we’ve got all the facts. Based on my personal experience, I felt we could go to (U.S.) Highway 80 in west Alabama, but after this sampling project, we could have the data to back it up.”

Sykes does offer one caveat on lines of demarcation for hunting seasons.

“There will never be a clear-cut line,” he said. “There will be some deer south of (U.S.) Highway 80 that will rut early. There will be some deer north of (U.S.) Highway 80 that will rut later. But you have to have definitive boundaries that you can work from. If you look at some places in north Alabama and you slide that season to take away those 10 days in December, you’re going to completely cut them out of the rut. So, it’s not a one-size-fits-all thing.”

“Here is the main point I want to make about the season shift – if you pressure the deer so much in December and January, you’re not going to see the effect you’re looking for in February. If they are not pressured the last two weeks of January, February will likely be fantastic. If deer are pressured all the way through, I don’t think we’ll see a big increase in deer harvest. I just think pressure is that big a factor.”

David Rainer works with the Alabama Department of Conservation and Natural Resources in Information & Education.

COMMENT