2009 | Buck Manager

The Spread of CWD in White-tailed Deer

Serious diseases such as chronic wasting disease (CWD) can be detrimental to whitetail deer management programs with mortalities impacting local deer numbers as well as regional and potentially even statewide deer populations. State agencies around the country have been monitoring CWD in deer herds for many years now, and they know that it is caused by prions, but much about the spread of the disease was unknown until now. Researchers have discovered that deer asymptomatic for the fatal brain condition known as CWD excrete the infectious prions that cause the disease in their feces.

The finding suggests a reasonable explanation for transmission of the disease among white-tailed deer, mule deer, and possibly elk and moose in the environment. While the study reveals that prions are shed in feces of symptomatic deer as well, the discovery that the infected deer shed prions in their feces many months before they show clinical symptoms is the most unsettling. White-tailed deer, mule deer, elk and moose inadvertently consume feces and soil in the course of their daily browsing and grazing.

The prion is an infectious form of the normal prion protein, which has been found in all mammals examined, including humans. The lethal, infectious form induces the normal protein to twist into a malconformation, initiating a disease process that ravages the brain. Prion diseases, seen in cervids, sheep, cows and humans, are also referred to as spongiform encephalopathies. In wid and captive deer, researchers now know that the inadvertant consumption of feces is how the disease is transferred from animal to animal. So what’s the next step?

With this information in hand, the researchers set out to determine whether the animals could develop chronic wasting disease through long-term consumption of contaminated feces. They did so by measuring the amount of prions contained in the feces of orally infected deer up until the time they became symptomatic and then calculated whether prolonged exposure to the concentrations of prions in these feces would be enough to cause the disease.

“Prion levels in feces samples of asymptomatic deer were very low compared to those in the brains of the same deer at the time of death,” says the lead author of the study, Erdem Tamguney, PhD, an assistant professor at the Institute for Neurodegenerative Diseases, based at UCSF. “However, the total number of prions excreted over time was sufficiently high enough to cause disease in other deer.”

The susceptibility of animals to infection, he says, may also be increased by the simultaneous ingestion of clay soil, which is thought to enhance the infectivity of prions, possibly by slowing their clearance from the gastrointestinal tract.

“Our findings suggest that prolonged fecal prion excretion by infected deer provides a plausible explanation for the high level of transmission of chronic wasting disease within deer herds, as well as prion transmission among deer and other cervid species. Our work may also explain transmission of scrapie prions among sheep and goats,” says senior author and Nobel laureate Stanley B. Prusiner, MD, UCSF professor of neurology and director of the UCSF Institute for Neurodegenerative Diseases.

The study did not examine whether CWD could be transmitted to humans via exposure to deer feces. To date, transgenic mouse studies have indicated that chronic wasting disease does not transmit to humans, but scientists remain open to the possibility that it could.

“We can only say that prions of chronic wasting disease have not transmitted to mice genetically engineered to carry the normal, healthy form of human prion protein in earlier studies,” says Prusiner. “That said, we do not know for sure that deer or elk prions cannot be transmitted to humans.”

Time to Rattle for Whitetail

Fall is here, food plots are in the ground and the deer hunting seasons are underway. Except for conducting a couple of controlled burns in the near future, the only thing left to do deer management wise for me is to harvest and record the deer we need (or would like) to remove. Though most deer hunters hunt whitetail by setting up over a food source, whether it be a feeder or a food plot, there are much more active ways to bag a buck.

When it comes to hunting there really are only two ways to go: Either you can go to the deer, or you can bring the deer to you.

Rattling for Bucks

Though many hunters have read about rattling bucks in, or have at least seen it on TV, many have yet to give this method of hunting a serious shot. Or maybe you tried it once, but didn’t feel confident, it didn’t work so you packed it in. Ratting for bucks can work, especially if you incorporate the technique into your hunting on a regular basis.

I suspect many deer hunters have picked up a set of shed or cut-off antlers and have at attempted to rattle up a buck, but their lack of success caused them to quickly dismiss the effectiveness of antler rattling. Those antlers then went back to collecting dust at camp. So as effective as rattling can be for whitetail, most of time it will not work and you are not going to bring in a buck on a string. It does work, however, and when it’s hot, it’s hot!

Best Time to Rattle?

Rattling can work at any time during the hunting season, but it is typically most effective just prior to the rut, during the pre-rut. At this time, antler rattling can be an effective way to bring whitetail bucks right up into spitting distance. I’ve seen bucks come running out of the brush with as little as two seconds worth of antler rattling!

Of course many, many times I’ve rattled antlers together only to attract the attention of area squirrels, or even worse, nothing at all. During the pre-rut, bucks are busy establishing dominance for breeding purposes, setting up territories, and working off an excess in testosterone. It is also during this time in which they are most vulnerable to rattling, so this is the BEST time to rattle.

Rattling Antlers Attracts Attention

When it comes to rattling, let me tell you that you never really know what you are going to attract. I’ve had all sorts of deer respond to rattling. I can only guess they all want to run over and see who is fighting — and who will win? Some bucks want to participate, some are just curious. I’ve had does, spikes, middle-age bucks and mature bucks all come to a set of rattling antlers.

All age classes of bucks will respond to rattling more or less at the proportion in which they occur in the population. Younger bucks probably respond at a higher percentage overall and mature bucks probably a little less overall, but it’s not easy to measure since mature bucks are smarter. Older bucks often respond to the sound of rattling antlers by moving downwind of the action and then creeping in. Younger bucks do not always take such precaution, so there is a chance some of those more experienced bucks are detecting us before we detect them.

If a good percentage of the local buck herd is made up of young bucks, then that is probably what you will bring in. If, on the other hand, there are a good number of older bucks in the area, then you have just as a good of a chance of bringing them to you as younger-aged bucks. In fact, you probably have a much better chance of bringing them to you rather than simply sitting and waiting to see them — because they may have stayed “brushed up.”

Rattling, Battling Bucks

A friend of mine spotted a huge whitetail buck last year on public land right as the season started. The buck showed up on a couple of his game camera photos before season, but he got a glimpse of the buck the second day of archery season as the animal walked by at 200 yards. At that point, he then made it his personal mission to hunt that deer for the remainder of the season, even if it meant he ended the year with no buck at all.

To make a long story short, he hunted long and hard with no success, but one cold morning a few weeks later he decided he needed to be more aggressive. He had decided that if he didn’t change then his success rate was not going to change. The best trick in his book: try to get near the buck’s core area and rattle him up for a battle.

The right day came: Temperature perfect, wind great and he was able to rattle that buck to within 25 yards and made a perfect double-lung shot. He said after his first rattling sequence he could see the buck, which scored over 170 Boone and Crockett inches, running at him from over 400 yards! Sometimes it helps to bring them to you.

So rattling can work, but don’t expect it to work every time.

Game Warden Bags Big Non-Typical Buck

Each fall, deer hunters think of cool, brisk mornings and dream of big whitetail bucks running through the woods. Although every hunter wants to bag a monster buck, I don’t have to tell you that they are not exactly behind every tree. Especially when it comes to huge non-typical East Texas bucks. But like I always say, hunting is hunting and you just never know what will step out. Well, what stepped out for Texas Parks and Wildlife Department’s Kaufman County Game Warden Eric Minter was a big 27 point non-typical white-tailed buck. Not bad. Particulary since this is his first buck with a bow!

That’s because this past Monday (10/19/09) the Kaufman County warden found himself as the lucky hunter staring down the buck of a lifetime from his treestand hung 20 feet high in a creek bottom filled with acorn dropping white oaks. When all was said and done, it was Minter putting his own tag on a whopper 27 point non-typical buck. While there is no firm green score number on the multi-tined monster whitetail yet, photos from the buck would lead one to believe that this deer will score well above the 200-inch mark as non-typical. Well over. Continue reading “Game Warden Bags Big Non-Typical Buck”

Whitetail Rubs Revisited

Hunters that have been out in the woods early this fall have undoubtedly bumped into some fresh rubs created by white-tailed bucks. Often times, discovering a new buck rub is enough to get my mind thinking about the deer that left the sign. How big is this whitetail? When was the animal here? Does he prefer the habitat found on this part of the property more? Where is the buck now? And, of course, will he return?

The general thinking on deer rubs is that big bucks rub actual trees and small bucks rub on saplings. This line of thinking suggests that the bigger the tree rubbed the bigger the whitetail buck doing the rubbing. Is this true? I would have to say yes, at least most of the time. The majority of bucks rubbing on larger trees are in fact larger antlered bucks. Bucks with large antlers tend to be larger bodied, mature, stronger, and as a result of all these attributes, dominant animals. Continue reading “Whitetail Rubs Revisited”

Texas Bowhunters Wet, Whitetail Well-Fed

If Texas’ archery season had opened a few weeks ago when habitat conditions were fair to poor at best, opening weekend might have been likened to shooting fish in a barrel. Well, it probably would not have been that easy, but just a couple of weeks ago range conditions were horrible over much of the state due to severe to extreme drought conditions. A lack of rainfall had resident white-tailed deer hustling to make a living. That is no longer the case. What bowhunters found this past weekend was that they themselves were the fish in the barrel.

Bowhunters that took the field on Saturday and Sunday in search of whitetail found themselves pretty soggy. Sure, the weather opening morning was decent, but rain and clouds literally sat over most of Texas for the rest of the weekend. As a matter of fact, those rain-makers are still out there and weather forecasters are calling for more precipitation for the remainder of the week. So from a bowhunter’s perspective, the archery opener was less than ideal and I suspect deer harvests numbers were way down. Texas’ white-tailed deer, on the other hand, are knee-deep in acorns and succulent fall forbs.

The hot, dry summer had deer scrambling in search of native forage, but recent, abundant rains have turned the once brown landscape Scotland green. Parts of Central Texas have received 12 or more inches of rain in the past couple of weeks—some in a single day! To add insult to injury, oak trees recently dropped massive acorn crops despite dry spring and summer conditions. I call it the bowhunters curse, and it happens more often than not.

Just when hunters think they have the white-tailed deer in patterned, here comes the acorns and fall forbs and then all bets are off. Well, the only thing that you can bet on is that deer will be spread out just like the food—and that if you’re set up near a feeder you will not see a deer. A heavy acorn crop combined with improved habitat conditions make it difficult for bowhunters to pin-point where deer will be feeding, unless there are only a handful of oak trees in an area. That is usually not the case.

But it’s not all bad, particularly for the deer. With fall at hand and winter around the corner, white-tailed deer need to fatten up for hard times ahead. The good acorn crop will help with that. Fifty percent of the calories a deer obtains from an acorn comes from fat; another 40% comes from carbohydrates. The timely rains have boosted habitat conditions and produced a bumper crop of cool season forbs. Forbs are high in carbs, too, but also loaded with protein—as high as 25 to 30 % digestible protein in some cases. So bowhunters may have suffered the early fall curse this past weekend, but Texas’ white-tailed deer have been blessed this fall.