Deer Management 2018: AS ALWAYS, THE SOUTHEAST DEER STUDY GROUP REVEALS SOME INTERESTING NEW FACTS ABOUT WHITETAILS.
The opening session is usually material not directly related to deer biology but more toward hunting in a modern society. I usually don't cover these studies, but the presentation by Steve Williams with the Wildlife Management Institute was extremely pertinent to the future of hunting.
We all know that we live in a changing world, but we don't tend to relate that to the decline of hunting. We should. Consider that 80 percent of kids 13 to 18 are "uncomfortable" in the outdoors. No wonder. They spend seven hours a day looking at screens.
With minorities becoming the majority in urban settings, and with hunter numbers and the funding for wildlife management dropping, the question becomes: Is deer management relevant to society today? Society cares about public health and nature, and they appreciate wildlife. They want to do things that are good for the family. Hunting does all that, and it does it safely. In order to get that message out, most state agencies need to change their structure, be more concerned about diversity, and improve their websites, social media presence, etc. As Williams pointed out, natural resources are held in the public trust for all citizens, and we're not sending that message. Now, the deer science:
Researchers at the University of Delaware conducted a deer mortality study in a unique area. The area had almost no deer predators--few coyotes, no bobcats, and no black bears. They collared 61 yearling bucks over two years and followed their survival. Of the 24 yearlings that died before their second year, 19 died from hunting (two-buck limit in the area), three from automobiles, and two from disease. Annual survival with no predation was 60 percent. Interestingly, survival was 75 percent on private land, but only 37 percent on public land.
Researchers also conducted a fawn mortality study on that same Delaware area that had no predators. First, they ran some predator surveys and found almost no coyotes in the area. There has been a lot written about the potential impacts of coyotes on fawns, so the fact that coyotes were essentially absent, as were bobcats and black bears, allowed for an interesting look at fawn mortality.
Thirty-day fawn survival was 61 percent. Half of all mortality that first month occurred during the first seven days of the fawn's life. Fifty-four percent survived 90 days. Since there were no predators, all mortality was natural (starvation, bacterial infection, drowning, and pneumonia). No such research has ever been documented, but this study showed that as little as one inch of rain in June can kill fawns. Additionally, doe age affected fawn mortality. Fawns from does four years old and older had higher survival.
Another mortality study looked at the impact of Hurricane Irma on 84 collared deer in southwest Florida. The hurricane hit on September 10, 2017, with the eye of the storm passing 13 miles from the study area. It brought 11.7 inches of rain and sustained winds of 134 mph. No deer died during the storm. Movement rates of does were 49 percent greater during the storm, compared to movements seven days before and seven days after the hurricane. Bucks did not alter their movement rates. Sixty-four percent of does, and 14 percent of bucks, left their home ranges during the storm, and deer selected pine-dominated uplands. This shows how resilient deer are, even during a major hurricane.
When someone tells me that they're doing quality deer management on their area but not getting any bigger bucks, I've learned to question their approach. They aren't doing something right--maybe shooting smaller bucks, or not harvesting enough does. Many studies show that when you practice quality deer management your deer herd gets healthier and you get bigger antlers.
Researchers from the University of Tennessee presented 14 years of data from the 18,500-acre Ames Plantation Hunting Club in Grand Junction, Tennessee. The area is managed for row crops and timber. Pre-QDM data was collected in 2002-2003, and the yearling and 2.5-year-old buck harvest was 90 percent. They imposed buck-harvest restrictions in three phases: 110 inches or 5.5-year minimum age from 2004-2005,120 inches or 4.5-year minimum age from 2006-2009, and 125 inches and 4.5-year age minimums from 2010-2016. Doe harvest quotas were set to achieve selected deer-density goals. They also placed ATV restrictions. Now, let's look at results that show what happens when you follow quality deer management protocol.
Yearling and 2.5-year-old buck harvest dropped to 55 percent during Phase One, 28 percent in Phase Two, and 23 percent by 2016. Doe harvest increased substantially, and the harvest of bucks 3.5 years old and older increased 467 percent by 2016. Hours hunted per mature buck harvest (3.5+) decreased by 45 percent. Buck observations per hour increased 84 percent, while doe observations per hour remained constant. So, members are seeing more big bucks as well as harvesting more in less time. Why? Because there were a lot more bucks age 3.5 and older. Of course, members of the hunting club were satisfied with the management program. One thing this study also showed: You need to collect data and enforce quality deer management rules, and when you do, the results will be there.
However, another paper presented by researchers from Michigan State University concluded that antler restrictions in 12 counties in the Lower Peninsula of Michigan did not increase the antlerless harvest, and did not recruit more hunters to the area.
In last year's report of the Deer Study Group Meeting, I told you about a study from Mississippi State University where they put bucks in pens on each side of an adjacent pen with a doe in estrus, and then they observed which buck she chose. The final results of that study were presented this year, and 80 percent of the does selected big-antlered bucks. You may recall that they removed antlers from different-aged bucks and replaced them with large and small antlers before exposing the bucks to the does. Thus, some large-antlered, older bucks had their large antlers replaced (in a unique way described in a previous column) with small antlers, and some small yearling bucks were given large antlers. No matter how old or how big the buck was, the does chose the buck with the largest antlers. This leads to many interesting questions. The authors noted one: Does make excursions just prior to estrus. Could they be seeking big-antlered bucks, and this then triggers estrus? Sounds crazy, but then again, would you have guessed that does would select yearling bucks over older, larger bucks? Apparently, antler size matters.
University of Georgia researchers reported on deer movements and weather. The study (2014-2017) overlapped a major drought in 2016. For that year, there was a significant increase in doe activity. Adult bucks were more active prior to and during the rut in the drought year.
Drought plays a role in the occurrence of epizootic hemorrhagic disease (EHD), as shown in work done by Michigan State University. They looked at 15 years of data and showed that drought severity was a significant predictor of EHD, and this relationship was greater at northern latitudes. Apparently, drought increases midge activity and can be especially important in new areas where EHD is emerging.
Another Georgia study looked at pregnant does that developed an immunity against EHD. Did that protect their fawns? Although sample sizes were small, fawns born to does that carried antibodies had better survival rates when the fawns were inoculated with the EHDV-2 strain of EHD than fawns born to does that did not carry the antibodies. Thus, immunity is very important when EHD hits an area, but there is the factor that each strain of EHD requires immunity. Just because a deer is immune to one strain of EHD doesn't mean it is immune when a new strain moves into an area, and new strains keep popping up all the time.
Due to space limitations, I've only touched on about a quarter of the papers presented at this meeting (I tried to select those of most interest), so this gives you an idea of the value of this gathering to the deer world. Each year the meeting rotates from state to state, and next February's meeting will be held in Kentucky. Just go to the Kentucky Department of Fish and Wildlife website for information. As always, Bowhunter Magazine will be there, and we hope you'll be there too.
Dr. Dave Samuel
Caption: Research studies show that does select larger-antlered bucks to breed with, no matter the buck's age. JOHN PENNOYER PHOTO
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|Title Annotation:||Deer conservation|
|Date:||Nov 1, 2018|
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