Every year like clockwork I begin to see posts on forums and Facebook about the rut being “on” because someone saw a buck chasing does. In most cases, especially in early october in Michigan, chasing has little to do with whether does are in estrus or not. It is just young boys being young boys. Juvenile antlered bucks begin chasing they day they shed their velvet. They are not chasing because the rut is on or there is a doe in estrus. They will chase any and every antlerless deer they come into contact with when they are not too discouraged by rejection or too tired.
This video shows typical young buck behavior Behind the Barn in my 8 acre research habitat on October 12th 2013. None of these deer are receptive to this buck and he does not discriminated on who he chases. he is chasing deer for the same reason the adolescents in the movie Porky’s peak through the keyhole of the door to the girl’s gym.
In either case, it has nothing whatsoever to do with breeding.
If you see a buck of 3.5 or older chasing a doe, well you can guess that she just may be ready to breed. Based on scientific studies, we know that the whitetail rut occurs in any given area roughly the same time every year. It may be over a three month window in the south, or a five week window in the north, and it may be affected by things like weather and hunting pressure, but it happens the same time every year. So plan your hunts around the times when mature bucks are most likely to be moving. In my home state of Michigan, that is around the first two weeks of November. After that hunting pressure changes daytime movement in many areas, but does not slow down the breeding process.