December 12, 2022
February 2022 found the Southeast Deer Study Group’s 45th annual meeting done via Zoom for the second straight year. No, it wasn’t quite the same as an in-person meeting, but we were treated to 33 major paper presentations and a number of student posters as well. Below is a summary of a handful of these presentations, which I’ve selected because I thought they would be of the greatest interest to Bowhunter readers.
Kip Adams was one of the opening-day presenters and, as always, he had impressive numbers to share. Kip summarized the economic benefits of deer hunting in 15 Southeastern states. Hunting license sales exceeded $251 million, and deer hunting supported 168,700 jobs. Hunters spent $84 million on wildlife plantings and paid over $1 billion to lease land that was primarily used for deer hunting. The data presented is Phase One of a three-phase collection of data that will end with the production of public-service announcements done via various media outlets to educate the public on the benefits of deer hunting. We know how important deer hunting is to our wildlife programs, and this work will take that information to nonhunters — an approach that’s long overdue.
We hear hunters talk about genetics all the time. Cole Anderson, a graduate student at the Caesar Kleberg Wildlife Research Institute, investigated the relationship between a sire’s antlers and his male offspring. They looked at the antlers of 329 buck fawns sired by 18 bucks in deer-management permit pens from 2007 to 2020. The fawns were caught and tagged, and then released into a 989-acre fenced enclosure. Every fall, these bucks were captured and their antlers were scored. The breeding value for each sire was calculated as the difference between the average antler score of his sons at 5.5 years of age compared to the population average for that age class. There was a relationship between the antler scores of sires and their breeding value, but it was weak.
I discussed this with Cole and found his answers interesting. He noted that it’s difficult to design selective harvest strategies based strictly on genetic potential, because phenotypes don’t always indicate genotypes. Some individuals have good potential but average phenotypes, while others have good phenotypes but fail to pass those traits to their offspring. As an example, he noted that he had one sire that had a maximum Boone and Crockett score of 200.5 inches. But his offspring, at age 5.5, only averaged 145 inches. Interesting.
One presentation I found particularly fascinating was given by Luke Resop from Mississippi State University. In recent years, various research has suggested that bucks are very individualistic. I guess they are sort of like people in that respect, because from a behavior perspective, we’re all a bit different.
This study showed that based on home-range characteristics, bucks have “personalities.” Luke and his coworkers looked at home ranges of 30 bucks that were fitted with GPS collars from 2017 to 2019. Based on their movements, Luke delineated two general buck personalities: “sedentary” and “mobile.” Sixty-eight percent had a sedentary personality, as indicated by having one home range (mean size of 600 acres). Even though they had one home range, sedentary bucks went on excursions, which are relatively long-distance, usually straight-line movements outside their home range, and taken especially during the breeding season. Mobile bucks also took excursions, but sedentary bucks took six times more excursions than mobile bucks did.
Thirty-two percent of the 30 bucks had a “mobile” personality, as indicated by the fact that they had multiple home-range segments where they would spend their time. They averaged five different home-range segments totaling around 12,000 acres. For mobile bucks, the mean duration spent in a home-range segment before traveling to another segment was 85 days. So, the mobile bucks just moved between their home-range segments rather than take excursions outside of their home ranges. Here’s where it got even more interesting.
Researchers identified two subpersonalities of mobile bucks: “shifters” and “bouncers.” Shifters were the homebodies of the mobile bucks and stayed in a home-range segment until shifting to their other segment. Over half of all mobile bucks were classified as bouncers. Bouncers did a lot of pinballing back and forth between home ranges, and these bouncing movements primarily took place at the tail-end of the breeding season — most likely in an attempt to find breeding opportunities in both home ranges.
Bouncers and shifters averaged three shifts between home-range segments per year, and these segments averaged 4.4 miles apart. They had one buck that had segments 18 miles apart, and his segments were separated by the Mississippi River.
This presentation shows just how difficult it is to pattern bucks. If only we could figure out which personality type the bucks we’re targeting have without using GPS collars (impossible, and illegal)…
Tristan Swartout, a graduate student at Auburn University, looked at a doe’s history to determine whether she was successful at rearing fawns. What factors determine whether a doe will be successful at raising fawns? That’s not an easy question to answer. To do this, Tristan looked at genetic samples and other data from 474 deer collected at the 430-acre Auburn Captive Facility from 2008 to 2019. He and his coworkers found that the ability to recruit fawns increased with age and peaked at 5.5 years of age. Body size was not associated with recruitment. They also found that does that recruited a fawn the previous year recruited 1.4 times as many fawns the subsequent year, compared to does that did not recruit a fawn.
During the study, 47 percent of does were consecutive breeders (raised fawns two years in a row) at some time in their life. These does recruited 75 percent of all fawns raised and 78 percent of all twin and triplet litters. This study shows the importance of older does in a population and suggests that a small percentage of high-quality females are responsible for the majority of fawn recruitment. My thoughts are that you probably don’t want to harvest a doe that has a fawn, because those does are probably going to raise fawns the next year.
John Kilgo, with the U.S. Forest Service, also looked at some long-term data to learn more about fawn survival in South Carolina. Sample sizes were small, but in general his results were the same as those of the previous study.
For example, Dr. Kilgo found that the age of the doe had a slightly positive affect on her successfully raising a fawn. Does that failed to raise a fawn during the first year they were monitored were 40 percent more likely to fail in the future, while those that were successful in the first year of monitoring were 22 percent more likely to be successful in the future. The conclusion of this study was that some does have innately successful behaviors, and that does without these behaviors may not learn them through experience.
Researchers in South Carolina also looked at fawn survival and used GPS collars to examine doe-fawn interactions during the first 21 days of the fawn’s life. We know that does will leave their young fawns for long periods of time, then return. They defined a visit of a doe to its bedded fawn if the doe came within 55 yards of her fawn and then stayed near the fawn for over one minute. Although their data has not been fully analyzed, they found that the more the does visited the fawns at night, the higher the risk of mortality. The conclusion here was that good mothers don’t visit when coyotes are most active (at night). They also noted that as the median distance between the doe and her fawn decreased, mortality also decreased.
Coyotes are a problem for fawns in regions of the Southeast. Jordan Youngmann and others from the University of Georgia used GPS collars to track 41 resident coyotes from Alabama, Georgia, and South Carolina during 2015 and 2016. They identified foraging areas where individual coyotes repeatedly returned to locations. They learned that resident coyotes preferred open-land cover throughout the year, while also avoiding roads. They stayed out of forests and selected forest edges except from April-June, when they foraged within interior forests away from edges. They noted that during spring foraging coyotes may select forest cover where fawns are more vulnerable to predation.
That’s a quick summary of some of the studies going on around the country. If there is deer research going on, you can bet you’ll hear about it at this annual meeting. Next February will be the 46th such meeting, and as always, Bowhunter will be there!