How Long Do Deer Breed? Do Barren Does Exist?

White-tailed Deer Breeding & Fertility

White-tailed deer are prolific breeders, meaning they have the potential to reproduce and grow local deer populations quickly over just a few years. The majority of whitetail does will give birth to twin fawns each and every year after their first birth, when they usually have just a single fawn. One of the biggest deer management issues in many areas, both suburban and rural, continues to be deer overpopulation and the resulting degradation of habitat.

It would seem that deer are in large numbers everywhere, but the fact is they are not. Many hunters often encounter animals in the field that appear to be barren deer, does without fawns. So what gives? How long do deer breed?

“Is there such a thing as a barren doe? I believe there is, as I have shot quite a few does in the 115 to 130 pound-plus weight range that have no signs of ever lactating; very small nipples, no evidence of ever having a milk bag. The nipples, as well as milk bag, are tight to the belly as to have never produced. I have friends that argue the barren doe thing, but I am convinced that there is such a thing. My theory is that they come into heat, get bred, but are sterile and do not take. Could you clear this up please? Thank you.”

Are Barren Does Out There?

Although some number of barren does can inevitably be found somewhere, they are very rare, comprising less than one percent of the doe population. Research on free-ranging whitetail deer has found that does bred when less than a year of age (fawns basically) normally produced a single fawn, with 10 percent of these animals bearing twin fawns.

Older does average almost two fawns each annually; about 60 percent have twins, 30 percent have single fawns, 3 percent have triplets and 7 percent have complications that result in no fawns being produced. However, the overwhelming majority of “non-performers” are not barren and can go on to successfully produce fawns in the future.

Using the numbers above, this means that about 160 fawns are born for every 100 does in the population. This shows just how prolific white-tailed deer can be, but it’s important to remember that just because fawns were birthed does not mean that they will survive.

Factors that Impact Deer Reproduction

Habitat quality, as in protective/hiding cover for fawns, and food availability, for lactating does, is extremely important for recruiting fawns into the adult deer population. This is where many properties fall short: inadequate deer habitat.

Source: “Failure of does to breed is not a problem, so where do the fawns go? Life is full of dangers for a fawn, and food and cover (fawning habitat) is the difference in living and dying for fawns. In many parts of the state, predation is severe unless there is adequate hiding cover for young fawns. Imported fire-ants are a problem for fawns in heavily infested areas, but their impact can often mask the real problem. Adequate deer nutrition is often limiting, and if fawns make it past fire-ants and predators to weaning, they still face the challenge of finding food and cover.

Fawn survival depends primarily on habitat quality. Malnutrition and associated problems are probably responsible for poor fawn survival in much of the state. Dry conditions aggravate the problem of inadequate food. “Empty belly disease” is the most limiting factor on whitetails in Texas. Delayed rutting and breeding could cause fawns to be born late, which would be a disadvantage on ranges where food is scarce.”

Whitetail are Fertile, Productive Animals

In short, observing does without fawns is not a barren doe issue. A large number of does without fawns by their sides, especially those in good physical condition, is an indicator of other deer management issues. Although the most common limiting factor of deer populations in many areas is a lack of deer habitat management, or more bluntly stated, poor habitat quality, I don’t believe this is the case in the situation presented by the questioner above.

In Texas, does with body weights of 115 to 130 pounds would be considered quite healthy. When deer have good, healthy body weights, one would expect the habitat to also be in good condition and that fawn recruitment would be high. In the case above, it’s suspected that predators could be the problem rather than inadequate nutrition. So, how long do whitetail deer breed? Well, they will produce fawns as long as nutrition is adequate.

Providing good deer habitat typically alleviates predator issues in whitetail, but there have been instances when predators at extreme numbers, particularly within high-fenced ranches, can become a serious deer management issue. Barren does are not the problem, but predator numbers very well could be.