A flash of bright blue caught my eye as I walked past my backdoor, and I looked outside to see the scene captured in part in this video. Several eastern bluebirds were congregated near the rear of my yard — one perched on a crape myrtle, another on a nesting box a few feet away and three on the ground nearby ... scrappin’.
I rushed upstairs to get my camera and came back down in time to hastily capture about 30 seconds of a tussle that lasted at least two minutes.
The bluebirds started gathering again in my yard about three weeks ago, and evidently, the competition for prime nesting spots can be fierce. The box we mounted on a slash pine about three years ago must be desirable real estate, even though the resident squirrels chewed around the entry hole, widening it significantly.
According to the Cornell Lab of Ornithology:
Males vying over territories chase each other at high speed, sometimes grappling with their feet, pulling at feathers with their beaks and hitting with their wings. The boxes and tree cavities where bluebirds nest are a hot commodity among birds that require holes for nesting, and male bluebirds will attack other species they deem a threat.
This seemed to explain the behavior I witnessed, except that at least one of the birds in the video appears to be a female. (In fact, there seem to be four or five females hanging around in and around my yard and two males that I can identify.) That’s not necessarily unusual, though, according to Chris Marsh, an ornithologist and executive director of the LowCountry Institute. “Yes, they’re very territorial and females do get involved,” Marsh replied after I emailed him this video. “It could be two pairs tussling with each other.”
According to Cornell, “Males attract females to the nest with a display in which he carries bits of nesting material into and out of the nest. Once a female enters the nest hole with him, the pair bond is typically established and often remains intact for several seasons (although studies suggest that around one in every four or five eggs involves a parent from outside the pair).
This morning, I saw a bit more of this aggressive behavior, albeit near our backyard feeders, not near the nesting box. I hope they can worked this out peaceably, and maybe make their way to the front yard, where we recently placed another box.
If not, however, Marsh said that during the winter, bluebirds in more northern regions will roost together in a box. Maybe these birds will bring that practice south.
Read more here: http://www.islandpacket.com/2014/01/30/2920201/angry-birds-see-how-bluebirds.html#storylink=cpy