Fall signifies the rut is near, right? Well, for some deer hunters that’s true, but for others the rut is nearly over. In fact, whitetails are rutting somewhere in the United States from August through February. Amazingly, they breed over this seven-month period just in the state of Florida! Designing a hunting season around the rut may be relatively simple in states with a consistent breeding season, but doing so in a state that varies as widely as the Sunshine State can get complicated.

Photoperiod is the Trigger

Photoperiod is the interval in a 24-hour period during which a plant or animal is exposed to light. Photoperiod is directly tied to growth, development, and seasonal behaviors in plants and animals.

With respect to whitetails, photoperiod regulates some hormonal production that is directly tied to antler growth and the breeding season. A diminishing ratio of daylight to darkness triggers behavioral and physiological changes that lead to breeding.

First, antlers mineralize and bucks shed their velvet. Next, bucks begin sparring, rubbing trees, and making scrapes. This transitions to some fighting to establish dominance and breeding rites and eventually to breeding.

Rut Factors in the North

In northern regions photoperiod is a much more precise indicator of seasonal changes. This is due to northern regions having a wider range of daylight lengths from summer to winter than southern regions, and climate being critically important for doe and fawn survival.

Does bred on time put little energy into fetal development during winter when nutrition is most limiting (energy demands are highest for the doe during the final stages of the pregnancy). Their fawns are born into a favorable environment from a temperature, cover, and forage perspective, and fawns are allowed maximum time to grow before the onset of the next winter. This also allows does to recover body condition and build the necessary fat reserves for breeding and winter survival.

The bottom line is northern whitetails have a narrow breeding window to optimize doe and fawn health and survival. This is why numerous studies across the northern United States and Canada looking at conception dates show the rut occurs in early to mid-November annually with very little year-to-year variation. In fact, these breeding dates are amazingly consistent from year to year – regardless of moon phase, weather patterns, or other variables.

Rut Factors in the South

In southern regions, breeding dates aren’t as cut-and-dry. The photoperiod change is less dramatic, the climate is less severe, and there is less need to breed “on time.” This may explain why the breeding window is wider, but it likely does not explain why some deer herds in central Florida have peak breeding in September while others peak one to three months later. Or why published reports show peak breeding in October in east Texas, December in Arkansas, January in Mississippi and Alabama, February in the Florida panhandle, and October in southeast Georgia. All of these regions share a similar photoperiod, so there are clearly some other factors involved.

Research suggests southern deer are still under the influence of photoperiod, but exact timing of the rut is more influenced by genetics and maternal factors, and the synchrony of the rut is more influenced by herd demographics. This means photoperiod controls the approximate season of breeding (fall or winter), but the deer herd’s genetics likely influence the exact timing of breeding.

The synchrony or “tightness” of the rut is then governed by how well the herd is managed. Herds with balanced sex ratios and age structures have “tighter” or more synchronous ruts, which leads to increased rutting behavior, competition for breeding, and enhanced hunting opportunities.

Deer Behavior

Regardless of where you hunt, the whitetail rut is the most exciting time of the year for deer hunters. Bucks travel more than at any other time of year, and they travel more during daylight hours than at any other point. They can throw caution to the wind to win the rights to breed a doe, and in doing so can inadvertently walk right by your stand.

Bucks are also more susceptible to calling and rattling during the rut, and research shows most bucks go on long range (1-3 mile) excursions during the rut. So, even if you haven’t been seeing what you’re looking for in the woods, if it’s the rut, keep hunting because that monster buck from down the road just may be cruising by your hunting spot today or tomorrow.

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