I have observed for some years, in late winter, a pattern of aggressive behavior by Yellow Rumped Warblers. The previously inoffensive birds take on a role of feeder cop, chasing off other species at every feeder they can cover. I'm a little embarrassed to say that I think I finally figured it out. Perhaps I was fooled that the birds eventually migrate northwards. But it strikes me they are responding to hormonal changes and compelled to defend a territory. Even if it's a temporary one. The nature of the territory may have to do in large part with food supply---no doubt the warblers need to build up an energy stock before committing to the migration. But even still, other migrants don't do this in winter here. The warblers are simply more wired. I take this as a sign that they will ship out within the next few weeks and leave our feeders in peace. And this will be welcomed. Right now they are simply too aggressive!
This Wingscapes BirdCam enthusiast and keeper of a well-stocked "bird cafe" has been watching birds in Cary for over 18 years. I adopted the BirdCam in December 2007 and have been working with the product daily, recording over 35 species locally and gaining significant experience with the use of this amazing device. I'm not a "power birder." While I enjoy birdwatching in the field, I appreciate the simple delights of the birds found in my own backyard or in places just down the street. These are truly interesting places and I never tire of the little stories told every day in those places. The birds are central to this experience, but expect me to talk about the things that also are part of the birdwatching experience here at Cary BirdCam, from buying bird seed to crunching numbers in the logbook. Thanks for being a reader!