What dictates drumming counts and cycle changes in grouse population!

[Shack]

This topic has been a cause of debate lately with my circle of friends. Is it winter and spring weather conditions, which also brings in habitat. Or is it the migration of birds of pray, in and out of Canada and U.S.. I do believe both have a roll in this, but some say one or the other has a much bigger play in it. Which one do you believe has a bigger role. I am kind of in the middle, but have been given heavy evidence about the bird of pray thing. I have heard when there are more eagles, hawks and other birds of pray migrating down from Canada, grouse are far less likely to drum because of attracting attention to them selves or their young. Does anyone think Turkeys fall victim to birds of pray?

[sachem longrifle]

I saw a study done a few years ago that showed that birds of prey have some effect, but not alot. Birds of prey tend to hunt more open areas(ditches, fields, ect). If there is dense brushy habitat, hawks and owls have trouble getting grouse because of their larger wing span. I have seen years with alot of hawks around yet the cycle was still up. Hawks tend to get grouse when they come to roads. It's not uncommon to see a good number hawks and owls in the spring. If you ever see a drumming station, it has a good amount of over head cover and good amount of dense cover around it but not too dense as to allow a ground predator to sneek up on it. Predators are a natural part of the Grouse's world and Ole Mr. Ruffed is well equipped to deal with them. It's when there is too much fragmentation in the forest will he have trouble. One of the values of roadless areas.