To hear some hunters talk, you'd swear the rut plays out twice. We have the regular rut sometime in mid-November and a second, albeit lesser rut, sometime in December. Truth is, however, that it doesn't quite play out that way.
The so-called second rut isn't a rut at all--it's just the occasional breeding event so to speak. There is no significant ramp up of buck activity. By mid-December most bucks are plenty shy and not about to take too many chances. Will they breed an estrus doe if one shows up in their neck of the woods? Sure. Will they march around in a fog of testosterone to find one? Hardly.
So what's all this second rut stuff about? Simply, if a doe did not conceive during the primary rut, she will recycle 28 days later. However, in areas of sound deer management (with good buck-to-doe ratios) and decent deer habitat, almost all does conceive first time around.
Not all instances of late-season breeding are the result of re-cycling does. Some fawns are capable of reproducing at 6 to 7 months of age. This typically won't occur until a fawn is 70 pounds or more. However, fawn conception rates vary widely by location. In Midwest states with great habitat and healthy deer, more than 50% of doe fawns conceive, but 10% to 15% is more the norm and single digit fawn breeding is typical in the Northeast.
So, despite an occasional flurry of buck-chasing activity, these late-season breeding events are typically isolated and short-lived. The occasional doe in heat will attract attention for a couple of days and then everything will go back to normal. And back to normal for late-season bucks means repairing tired and broken bodies and staying out of a hunter's sights.