Maybe this is obvious to everyone on this list with people reporting the call of a cardinal or "raven with nest material" in February. But I also have been noticing sounds of spring (cardinal, titmouse, Carolina Wren, ...), crows checking out tree tops and pairing, crows bombing raptors,... since February 1st (maybe even second or third week of January?). I meant to write dates and temps in my notebook this year, but didn't.
It seems like all of this is happening a month or two early, am I wrong? Are there any scientific studies that show what triggers the timing of these territorial behaviors? Could it be a certain number of days above freezing? I know the media talks about the growing seasons lengthening and things blooming earlier,... but I haven't seen anything written on bird nesting behavior. Just curious, thanks! Sandy