Why Whitetail Fawns Rule (The Second Rut, That Is)

doefawnrutThis past week, we looked at the many fallacies of the second rut. Today, we’ll discuss the true foundation of the second rut: doe fawns. Surprisingly, many doe fawns can breed before their first birthday.

According to Deer & Deer Hunting’s John J. Ozoga, the key to doe fawns achieving estrus is tied to attaining the threshold of fat-to-lean body-mass ratio necessary to achieve puberty. Many factors dictate if or when that will occur, including nutrition, social stress, environmental stress, health of the mother and the date of birth.

So it’s easy to understand that doe fawns breeding during their first year won’t fall into a neat timing window. In fact, that can occur anywhere from the later stages of peak breeding all the way through January.

By Steve Bartylla

Anecdotal evidence is never as solid as thorough scientific research. Still, it can be revealing. Throughout my 37 years of hunting the Midwest and points North, I’ve yet to see a mature doe exhibit signs of estrus in December or January. However, I’ve seen doe fawns do so many times.

Though a few die-hard hunters I know have seen mature does show signs of December or January estrus, they agree that the number of estrous doe fawns they’ve seen during that time far exceeds the rare sightings of mature estrous does.

Because doe fawns are primarily responsible for the second rut, it’s impossible to accurately predict when it will occur. In reality, it’s spread out across a two- to three-month period.

When a fawn or two enters estrus, there can be a brief yet intense flurry of rutting buck activity.
However, it will be short-lived. The buck population would risk suffering very high mortality rates if it wasn’t.

Mature Midwestern and Northern bucks are often in tough shape come December. They commonly lose 20 to 30 percent of their body weight during the pre-rut and rut. Many are also nursing wounds from fighting.

Meanwhile, winter offers survivors their seasonal low point for food, in quality and quantity. And you must figure in cold and snow, which stress bucks even more.

These bucks cannot survive an extra month or two of extreme rutting behavior. They simply must focus more on survival than breeding.

That doesn’t mean bucks will pass up late breeding opportunities. However, they seem to pick their shots when going out of their way to find them. The days of spending 20-plus hours on their hoofs, doing nothing but searching for estrous does, are done. Their survival depends on it being finished.

The traditional view of the second rut is far more fallacy than fact. You will not see hordes of does miss out on finding a mate during peak estrus only to cycle back 23 to 30 days later. It just doesn’t happen.

However, some does will enter estrus later than others, and there are doe fawns to consider. Add that together and some breeding occurs after the peak breeding phase.

Luckily for hunters, mature bucks appear to key in on these opportunities far more than younger bucks. No, they won’t spend December and January running wild, but they take advantage of some opportunities. Understanding that can be the first step toward getting a crack at these monster second-rut bucks.

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