I'm not looking to start an argument here, but disagree with the statement that "cold weather increases the testosterone in bucks". From the scientific reading that I've done, it's changes in day length that stimulate the pituitary gland in the brain (via photoperiodism or biological clock) which regulates the production of reproductive hormones like testosterone. Thatcolder weather and the changes in day length happen to go hand in hand is a simple coincidence, but the colder weather itself has nothing to do with an increase in testosterone.
ORIGINAL: Washington Hunter
The cold weather increases the testosterone in bucks, but it does not make the does want to breed or go into estrous.
The amount of daylight is what causes the rut to kick in.
Does go into heat or estrous for only 24-48 hours each, and when they go into estrous can't be predicted precisely.
We see bucks chasing does because one or more does has come into heat and the bucks know that the rest of the does will come into estrous at any time.