Use trail cameras and mineral sites to figure out whitetail fawn survival rates.
As a hunter and land manager, a spring fawn is truly a sight to behold. Standing uncertainly on new legs, the whitetail fawn represents the success of the species on the landscape while at the same time acknowledging the fragility of wildlife populations in an increasingly non-wild world.
Managing for whitetail deer is more than just trying to attract and hold big bucks, it helps shape and understand the health and structure of the deer herd that you hope those big bucks will come from. One of best ways to do this is through tracking fawn recruitment, an exercise that will give you a much better understanding of herd structure, health and predator impacts.
Completing a whitetail fawn recruitment study is in the budget and experience of most any private or public land hunter, the only tools needed are minerals and a trail camera or two.
Fawn Recruitment Defined
Fawn recruitment is the percentage of fawns per adult doe (1.5 years or older) that survive until fall. Recruitment does not equal fawn birthrate, rather it points to the fawns who have survived their first months to enter the deer herd prior to the fall breeding season.
There are two factors that most inhibit or promote fawn recruitment. Prime habitat provides cover as well as great nutrition, leading to healthier does and protected fawns. The presence of high quality bedding and fawning habitat can go a long way in counteracting the affects of the second factor; predation by coyotes, wolves and other predators.
A recent study completed in Georgia showed the effects on fawn survival after most of the coyote population had been removed from a test site. Prior to the removal of the coyotes, fawn recruitment was calculated at 0.65 fawns per adult female. During the two years following the predator removal, fawn recruitment rose to 1.01 fawns per adult female.
Measuring Fawn Recruitment
Where legal, the placement of trail cameras over an attractant is a great way to gauge fawn recruitment. In my management plans, I have found the placement of minerals during the spring fawning months provides much needed nutrients to newborn fawns and the does that have carried them all winter. We use Trophy Rock, which is all natural and free of any “flavoring” such as sugar, molasses and fruit juice, making it legal to be used year around in my home state of Minnesota. Always check with your state guidelines before placing minerals or other attractants out for deer. For the study, I keep the cameras and minerals out throughout the spring and summer leading up to the fall breeding season.
To conduct the study, place your camera and minerals in locations that are well traveled and near known bedding areas. How many to place on your property is up to you, but I think two locations per 100 acres would be sufficient. I typically do this on my southern Minnesota property in late April or early May, just prior to when does usually give birth. I than check the sites every two to three weeks, downloading the camera data and replenishing the minerals as necessary. In the fall, a sample time of only 3 weeks is sufficient to get your data, but I like to run the study from spring until fall, creating a early and late sample to better understand how the population changed during the season.
Don’t worry about distinguishing between individual does and fawns, as that can be near impossible. Rather, count and record each doe and fawn sighting, taking care not to confuse a doe with last years buck fawn. At the end of the study when you run the numbers, the ratio between does and fawns will work out regardless of how many times you counted the same individuals.
In the photo above, you can see a single doe watching over five fawns at a mineral block site. The fawns, a set of twins and a set of triplets are the offspring of two does (one of which is outside of camera view) that have established their core area on the property. As of January, only one of these fawns had been lost to predation or other unknown causes; the remaining four fawns hopefully survived the winter and established themselves as part of the local deer herd. The survival of the four fawns is a indicator of good habitat and cover, as well a testament to the survivability of deer.
Calculating the Results
Once you have your doe and fawn counts, its time to calculate the results. To do so is actually pretty easy; you simply divide the number of fawns from the number of does. For example, if you counted 350 fawns and 425 does, your recruitment rate would be 0.82.
As a point of reference, the Quality Deer Management Association in their 2016 Whitetail Report found that the national average of fawn recruitment rate was 0.58 fawns per doe, which was down from 0.69 fawns the previous year, indicating a nationwide decline in fawn recruitment. The average of 0.58 means that it took almost four does to recruit two fawns in 2015. This number might surprise many, but its important to note that not every whitetail doe will be bred in any given year, especially young females. The spread of predators such as coyotes and black bears through the southeast is likely having a devastating effect on local and national averages as well.
Now more than ever, as a hunters in North America we are stewards of the resource, and the best way to manage deer as a resource and ensure their place in the future of American hunting is through sound science. This requires consistent herd monitoring; not just calculations made over one season, but keeping track of trends across many years. It also means we need to use the data wisely, and at times go against the short term wants of the those that utilize a given property for deer hunting.
This may involve the harvesting of less does to increase the number of fawns, going as far as halting doe harvest all together for a few years to rebuild a herd. It also might mean that more deer need to be killed, if the current numbers outpace the habitat available to sustain them. The only way to do that is through proper analysis, and conducting this simple fawn recruitment study on the property you hunt is a great way to begin to do it.