Scientifically speaking, "the rut" is defined as the time when a buck can breed, not when does do breed. Bucks can breed as soon as they shed velvet, and can usualy continue breeding until they shed their antlers. This is all controllled by testosterone level, which is controllled by photoperiod, age, health and social status. There is evidence that high testosterone levels in older bucks, which causes them to rub and scrape, suppresses the urge to rub and scrape by lower raning bucks.
Does are triggered into estrus by photoperid. But they may be induced to come in to estrus by the pheromones (scents) left by dominant bucks at rubs and scrapes. This helps to synchronize peak breeding between bucks and does, so that breeding occurs at the righ time of year. However, when there aren't enough 3.5 year old or older bucks in the herd, or when there are far more does than dominant bucks in the herd, the breeding phase may begin late, or last longer than 45-60 days. In some places breeding of 80 % of the does may take up to 4 months, especially down south, where deer can breed from Aug. 22 until Mar. 14. (according to studies by Robert McDowell in 1970).
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The two 3.5 year old bucks in the elk pens (in southern Minnesota) shed velvet during the first week of April, don't have swollen necks yet, and have just begun to check the does.
T.R. Michels, writer, speaker
Trinity Mountain Outdoors
[email protected]
T.R. Michels