Army Deer Mngt. - Study Data

[grundsow]

Thought you management-types might find this interesting...

The U.S. Army Corps of Engineers manages 8 million acres of land nationally, including 22,000 acres of forestland and fields surrounding Raystown Lake in Huntingdon County (PA). The Corps reversed a growing habitat problem, said staff biologist Jeff Krause, and increased opportunities for hunters by bringing deer numbers and habitat into balance.


Krause will explain how Raystown solved its deer problem, and surprising ways that hunting impacts deer densities, at a free seminar 7 p.m. March 22 at the Richland High School in Johnstown (814-659-1280).

The Corps tripled the amount of road access open to hunters, but said Krause, "that wasn't going to be enough."

The real problem, they found, wasn't the number of deer per square mile, it was the imbalance between deer and vegetation.

"The number of deer in a given area tells you very little about whether the area can support more deer or if the deer need to be reduced," he said. "It depends on the quality of the landscape."

In 2003 the Corps developed a deer management plan and enrolled in the Game Commission's Deer Management Assistance Program..........
A year into the program, a combination of post-hunting season aerial infrared deer surveys, spotlighting, pellet counts and habitat evaluations tallied 54 deer per square mile, with densities in some areas as high as 80 per square mile.


After dropping the deer population in the first years of the program, diverse vegetation is back and surveys show the deer population is rising -- from a post-hunt 12 deer per square mile in 2008 to 15 deer per square mile in January. Last fall's pre-hunt estimate of 26 deer per square mile correlates with the deer audit's low-range estimates for 4A

 

[BSK]

"The number of deer in a given area tells you very little about whether the area can support more deer or if the deer need to be reduced," he said. "It depends on the quality of the landscape."


That quote says it all. Whenever I evaluate a property, one of the first things the landowner is going to ask is "How many deer do I have?" They are always shocked when I tell them, "I don't know, and that number isn't important." What IS important is how the current deer density--whatever it is--is relating to the available habitat. How much of the best food sources are being eaten away? How much of the moderate and low-quality food sources are being eaten? That tells you what you need to know about deer density.

Also remember that the deer density versus food availability assessments should be done RIGHT NOW, in late winter just before spring green-up. This time of year is when food availability is at its lowest point. Deer may have virtually unlimited soybean fields to feed in during the summer, but what are they eating in winter, especially late winter? How much of that late-winter food are they eating?

 

[BSK]

Ten years ago, I think many of the first hunters to start managing their lands and deer herds thought we deer managers hated deer. We were constantly stressing "kill more does." However, we did this because the most common problem we saw on individual lands was too many deer for the habitat to support. To improve individual animal performance, deer densities needed to be lowered.

Over the first few years of these intense doe harvest polices, a new problem cropped up and this was the "doe sink" problem. As hunters on one property killed does, does from surrounding properties filtered in during the offseason to take advantage of the locally lower deer density and greater availability of food. This led to frustration for those practicing high doe harvests. Basically, the more does they shot the more does they had the next year due to infiltration of surrounding does. However, this problem was occurring because hunters on surrounding properties were not shooting does.

Luckily, times have changed. Through various means, hunters have gotten the message about shooting does. Now most hunters are will to and do shoot does. In result, these doe sink problems are disappearing. In fact, these doe sink problems have disappeared to the point I'm finally starting to tell hunters to begin backing off doe harvests. Their doe harvest policies--along with the EHD outbreak of '07--have done their job. Deer densities are lower.

Deer densities are now at a point that I've told several landowners to stop shooting does (or at least limit doe harvests to youth hunts only) for the next year or two. These landowners have worked diligently to not only harvest does but greatly improve the food resources of their properties. They have planted numerous food plots to provide high-quality food sources and intensively managed their habitat to produce a large volume of moderate-quality food sources. After recent inspection I found that these properties have considerable high-quality food source going unutilized in late winter--normally the lowest food source time of year. Now this means individual animal performance is at peak values (born out by some truly impressive bucks being harvested the last few years), but the current low density of deer is producing a less enjoyable hunting experience. The hunters/landowners have decided they would be willing to give up some of the current peak quality for improved deer sighting rates hence I've recommended backing off doe harvests for two years and then reassessing the situation. Basically, they will back off doe harvests until the deer density climbs to the point that high-quality food sources are being completely utilized in late winter and moderate-quality food sources are displaying some browse pressure.

The point is, heavy doe harvests don't have to go on forever IF surrounding land-owners/hunters are also shooting does. Eventually deer densities will be decreased. But only browse assessments at this time of year will tell you that. If top-quality food sources (especially highly attractive food plot plants) are going unutilized at this time of year, backing down doe harvests may be an appropriate action. Having more deer can be a good thing (it's a lot easier to produce mature bucks when you can have 30 bucks instead of only 15) as long as you have the food sources to support them at the lowest food-volume time of year.

 

[Locksley]

GOOD info thanks .

 

[BSK]

BSK, would you identify the most common natural species of browse deer in Tn use at this time of year?

The highest value foods I assess are food plot plants, especially "candy" plants like corn left standing. Secondarily winter grains such as wheat and oat.

A key indicator "moderate" value foods would be honeysuckle and/or greenbrier.

 

[grundsow]

A key indicator "moderate" value foods would be honeysuckle and/or greenbrier.

That's very interesting. Around here in SE PA the deer seemingly refuse to switch to woody browse and continue to focus on the Japanese vine honeysuckle, and to a lesser extent the native greenbrier and invasive multiflora rose stems.

This year though was different, the 3 feet of snow for several weeks had deer trapped and consuming ALL the honeysuckle and starting to hit woody browse like sassafrass, green ash, red maple, and maple leaf viburnum. In a few weeks the multiflora rose should begin to leaf out and I expect the deer to flock to it. This unusual snow has got to put a hurtin' on fawn recruitment and antler development.

 

[BSK]

Certainly. That's why areas that regularly see long-duration snow cover have winter mortality issues.