The ability of hens to re-nest has been proven time after time. I would rather do a habitat improvement regardless of the time of year it gets done. Destroying a few nests will be negated by the amount of birds you'll draw from surrounding areas. Sometimes a warm season fire is needed to knockout the undesired hardwoods in your timber stand. We have a 40 acre stand of thinned pines that used to hold birds but the sweetgums are so thick now that the birds have moved elsewhere. I wish they'd light it up now. The February burn they did 2 years ago only made them come back thicker.