The warblers have been filtering into my area after a long, cold winter, and I've noticed that some of them seem to establish their territories in pairs. I'll hear two of a certain species calling back and forth, not far apart from each other--and then I'll go for another mile of silence through the forest, only to hear another two males singing across just a few hundred yards. Some of these paired territories remain stable for the entire singing season.
I don't notice this with every species, but there are a few where it seems to hold true. If this is a real effect, is this a case of two males grudgingly carving up an especially rich patch of habitat? Or are there benefits to having a close neighbor, which would lead them to establish territories close, but not too close? If anyone has any insights or similar observations, please send them to me off-list; I'd be very interested to know what might be going on. Thanks, J. A.
