The Second Rut: More Fiction Than Fact?

2ndrutThe premise is simple: Buck-to-doe ratios are so woefully out of whack there’s no way all the does can be bred during peak breeding. It’s also understood that does not impregnated cycle back into estrus 23 to 30 days later. So if you wait the number of days in the does’ cycle past peek breeding, you’ve nailed the timing for the second rut.

By Steve Bartylla, Deer & Deer Hunting contributor

That apparently provides hunters with a basic grasp of math a tremendous advantage. After all, because at least some does were bred the first go-around, there should be about the same number of bucks chasing fewer does. Therefore, bucks must search harder to find does and fight off even more bucks to win the right to breed.

At first glance, that seems logical. In fact, it sounds like a Northern or Midwestern hunter’s dream. If it were true, I’d forget the rut and take the seemingly much more intense second rut every time.

There’s only one problem: It’s a dream, not reality.

After hunting “the second rut” more times than I can remember, I’ve still not seen a horde of bucks dogging a mature doe in early December. Sure, I’ve seen that occur with doe fawns. However, those activities are spread out from mid-November through the end of December, and research reveals that fawn breeding even occurs in January.

All of that begs the question: Is the second rut reality or fantasy? It will take a greater mind than mine to answer what occurs and why with the Southern rut, but it’s actually fairly easy to answer that question regarding the North and Midwest.

The foundation the second rut is tragically flawed in three ways. As with almost anything, a flawed foundation makes the structure unstable.

The first problem regards horridly skewed buck-to-doe ratios. Research has revealed that achieving anything higher than 1-to-3 is almost impossible in the wild, and even 1-to-2.5 is tough to hit.

Of course, we’re talking pure bucks to does, regardless of age. Those numbers hold true if you toss out the fawns. However, even on the best managed grounds, they’re exceeded when referring to a ratio of mature bucks to all does. Using that criterion, you can achieve the wildly skewed ratios folks often cite. However, you can’t when comparing all males to all females, even when tossing out the fawns.

The next problem involves breeding does. A 1½-year-old buck is just as capable as Mr. Big. No, he doesn’t have the rutting rituals down. He wastes a lot of energy on lost causes and is relatively clueless. Still, research reveals that young bucks do a good share of the breeding, even in populations with healthy age dynamics. Heck, even nubbin bucks can breed after they hit certain developmental thresholds.

Finally, not all does enter estrus at the same time. Even in far Northern ranges, where the breeding window is tighter, some does come into season early, most on time and some late. Those that hit on time are spread out across a week or more, with that on-time window stretching to almost a month in the Midwest.

When you factor in everything, pitifully few — if any — does are missed during their first estrus cycle. Sure, some come in a bit later than normal, but that’s usually because of injury, social stress, nutritional stress or reasons other than having been missed during their first estrus cycle.

Next week: The fawn factor

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