Trail cameras provide us with a great way to survey deer populations, identify bucks and scout deer movement before hunting season begins. There’s even a pre-season baited trail-camera survey method to analyze the structure of the deer population and catalogue the majority of bucks hanging around during the two-week survey window. However, that doesn’t mean baited trail-camera surveys are without flaws or that they reveal the full extent of your hunting opportunities during deer season.
Whether you use trail cameras for a formal two-week survey or just informal summer deer monitoring, a lot can happen as summer gives way to fall and the rut. How well do late-summer trail-camera photos reflect the population being hunted during deer season? To investigate this question, our team with the UGA Deer Lab set up a large experiment. Before we get into the study, let’s look at what we know about why bucks might change locations from summer to fall.
Why Bucks Shift Locations
Research has shown bucks shift home ranges and movement patterns for many reasons.
Changes in seasonal resources, such as hard mast production in the fall can result in deer altering their movement patterns to seek out food rich in carbohydrates and fats to prepare for the coming winter.
Hunting pressure can cause deer to exhibit more nocturnal movements, change the way they operate on the landscape, or even abandon specific locations within their home range, at least until the pressure is let off.
Yearling bucks tend to disperse from the range where they were born just prior to the rut when they are around 18 months old, a built-in mechanism to reduce inbreeding within a herd.
And of course, the onset of the breeding season may cause bucks to shift patterns and expand their home ranges on the landscape to increase their chances of reproductive success.
The last point I make is an important one when it comes to the validity of results you get from baited trail-camera surveys and deciding how you’re going to spend your deer season – and who you’re going to chase. A lot can happen within a deer herd as testosterone rises, the velvet comes off, and bachelor groups dissolve.
The UGA Deer Lab Study
We conducted camera surveys on an ecological research site, the Jones Center at Ichauway in southwest Georgia, as part of my Ph.D. research. I established a 2,500-acre camera grid consisting of 25 baited cameras (about one per 100 acres) and 49 passive, unbaited cameras (about one per 50 acres). Baited cameras were operated following the original survey protocol designed and tested by Dr. Harry Jacobson’s team in the late 1990s. We ran baited sites in September for one week prior to setting up cameras to give deer time to find the corn, and then we ran cameras for two weeks while replenishing corn piles.
Following the conclusion of the baited survey, we set up twice as many passive cameras compared to baited cameras on deer trails and movement corridors to increase our chances of catching deer on their feet. We ran those cameras from October through December, with the Georgia deer season concluding in early January. Passive cameras can be thought of as a surrogate for what hunters might see from the stand without using bait. They are passively monitoring the deer herd without an attractant, which is also why we ran twice as many compared to baited cameras.
After the surveys wrapped up, the real work began. We collected around 10,000 baited camera images and 4,000 passive camera images. We tagged every occurrence of bucks, does and fawns in the image dataset. Tagging deer in photographs according to their sex or age class is time consuming, but the real headache comes with identifying every unique buck in the surveys. This identification process is inherently subjective and relies solely on the observer’s ability to tease apart bucks based on antler configurations.
By our estimate, we ended up with 68 unique bucks during the two-week baited camera survey and saw 70% of those again during the deer season on passive cameras. An additional 43 bucks were picked up on passive cameras during the season, a 60% increase from the original baited camera survey’s unique buck list, with the majority of new bucks showing up during November and December (breeding at Ichauway peaks the last couple days of November and the first week of December). In total during the deer season, we detected 90 unique bucks on passive trail cameras within the 2,500-acre study site.
This means we had some bucks leave the property (or avoided having their picture taken by passive trail cameras), and we had new bucks show up that were off property during the baited camera survey (or never found our corn piles at baited camera sites).
Bucks Closed the Gap With Does
To illustrate this shifting on the landscape, we developed heat maps of buck and doe detections within the camera grid based on the number of images captured, with higher numbers of detections showing up as warmer colors, and fewer numbers of detections being represented by cooler colors.
During the September baited camera survey, bucks and does were highly sexually segregated, meaning bucks and does were using completely different portions of the 2,500-acre study site. Bucks favored the southern and western portions, and does preferred the northern and eastern areas of the camera grid. This is not a new phenomenon.
Sexually segregated deer populations have been well documented in the past, with some researchers claiming bucks and does should be treated as separate “species” during this time frame given their apparent differences in habitat requirements. This period of segregation is easy to identify. It’s when bucks are hanging out in bachelor groups and does are busy with fawn rearing and spending time in family groups.
However, once the number of hours in the day begins to decrease and the breeding season approaches, this period of sexual segregation begins to dissipate. According to our heat maps, bucks appeared to seek out areas that were consistently higher in doe detections across all months. What were once areas void of buck detections were now the areas generating the most images of bucks. It’s safe to assume, given our estimates of unique bucks and the turnover we saw, that bucks weren’t just shifting within the camera grid. New bucks were also showing up that had not been on the site prior to the hunting season.
Real World: Brantley Gilbert’s 375 Acres
Most of us aren’t hunting 2,500 acres like my research site, so what does this mean for the average hunting property or lease, say in Georgia where the research was conducted?
To bring this down to the reality of what we might encounter on a few hundred acres, my friend since childhood and musician Brantley Gilbert purchased a 375-acre property in June 2022. Brantley called me up and said he’d finally found a farm nearby in North Georgia, and we went to work.
We set up protein feeders, hung stands, and started working the dirt to develop a food plot program. But before all of that was done, we decided to conduct a baited trail-camera survey in late August to take inventory and see what the current deer herd using his new property looked like. We collected around 3,500 images and identified 23 unique bucks, with a buck:doe ratio skewing heavily in favor of does at around 1:4 (much like the northeast corner of the baited survey heat map from Ichauway).
In addition, we ran cameras on feeders and passively on trails and food plots throughout the entirety of the deer season and identified 14 new bucks, including the highest scoring deer by our estimate who had not been seen prior to the season. This was a 60% increase in the total number of bucks we saw in the baited camera survey, similar to the increase at my research site in southwest Georgia. This is likely a conservative estimate considering we didn’t try to identify new yearlings. The new bucks didn’t just show up during “rut week” either, and they didn’t stick around for the same amount of time. Some stayed for several weeks to months, some stayed only a few days.
Yearlings, particularly spikes, can be very difficult to tease apart, especially on passive cameras or feeders that aren’t perfectly placed in front of a camera like a corn pile during a baited survey. Which brings me back to my earlier point about the one great benefit of baited camera surveys: creating inventories of every buck visiting the baited camera sites. We don’t typically place a feeder with regard to camera location, we place them with regard to how easily we can back the truck up to refill them. Same with deer trails. We have to settle for the best tree for the job, which doesn’t always produce the “perfect” picture of a deer like a baited camera survey is designed to do.
Once we had the bucks from the baited survey identified before deer season, we found one that was old enough to hunt, aptly named “Mule” given his large forked right G2 that resembled mule deer antlers. But of course, once the bachelor groups started to break up, Brantley’s target buck hit the road. Sightings of the buck began to dwindle shortly after September until he disappeared off camera completely, with no word from any neighbors harvesting him. We could only speculate to his whereabouts. Maybe he had a preferred fall home range with a group of does to himself. Maybe he was harvested and we didn’t know about it, or maybe a car collision was his fate. Either way, “maybe” became the topic of discussion around Mule.
On the other hand, the oldest buck we identified on the baited camera survey, a 10-point that ran with the same bachelor group as Mule, was steadfast in his old age. He stayed on camera throughout the deer season and seemed to center his home range on Brantley’s farm. We found both of his sheds side by side in his favorite food plot this spring, which isn’t a big surprise. Old bucks tend to have smaller home ranges than their younger counterparts. They’ve seen it all and know exactly where they want to be.
Though neither Mule nor the old 10-pointer stepped out in front of a bowhunter last year, we were okay with that for the first season on the property. Brantley was on tour for much of the season anyway, and we look forward to seeing what the feed and food plot program will produce given more time.
Pre-season baited camera surveys can give you a good snapshot of deer density, sex ratio and buck age structure in an area. However, since they are typically conducted prior to deer season in late summer, they may not capture buck redistribution after the breakup of bachelor groups. All bucks are going to be different. Your target buck in velvet may stick around long enough for you to harvest him, or he may alter his patterns as the fall rolls around.
If your baited camera surveys or other trail-camera monitoring don’t show a good number of bucks before deer season, don’t despair. We recorded a 60% increase in bucks during the season that weren’t observed in the baited camera surveys on both the 2,500-acre study site and Brantley’s 375-acre farm. You may see more or less than a 60% increase, but you will likely see an increase. Being patient in the fall can pay off as things begin to change on the landscape, and keeping cameras running can help increase your odds of finding a shooter buck.
Lastly, since buck movements between summer and the hunting season can be very dynamic, working with adjacent landowners as part of a cooperative effort can be effective for maintaining quality deer in your area and increasing everyone’s odds at a good buck.
About the Author: Dr. James Johnson is a certified wildlife biologist, the Continuing Education Program Director for the Warnell School of Forestry and Natural Resources at the University of Georgia and has been a member of the UGA Deer Lab for the last decade. The research findings presented in this article were part of his dissertation research, advised by Dr. Karl V. Miller and Dr. Richard Chandler.