Tree Swallows (Tachycineta bicolor) are wonderfully acrobatic fliers and they are beautifully colored. I wanted to share some photographs of them from two different locations.

Just as we were leaving Goose Pond on our recent trip to Indiana, I noticed some Tree Swallows chasing one another near a dead tree. Others were perched on the top branches of the same tree.

After I watched them for a bit, it seemed that they were in competition about something.

The object of contention was a hole in the trunk, probably being considered as a nesting site. One bird was entering the hole (which is just below the bird on the right, another seemed to be defending the hole against all comers. Sexes are not discernible in the field, so I am not sure which sex is examining the nest hole, and which one is defending it.

Here the bird on the defense is holding off two contenders.

This photograph shows that one of the contenders has made a vertical attack from higher in the tree.

This photograph was taken a fraction of a second after the preceding one. The vertical attacker has nearly made contact.The other bird continues to examine the putative nesting hole, seemingly unfazed by the combat outside.

Change Location and Time

I also have some pictures of Tree Swallows taken at Horicon Marsh in Wisconsin. These are a bit later in the year, and young are already present in the nest. The photograph above shows one of the parents arriving at a nest hole. It demonstrates the wonderful control the birds have over their wings and the feathers in their tails.They really are quite acrobatic. The photograph also shows off the subtle color variations in their plumage.

In the photograph above, one of the parents has arrived at a nest hole with food for the chicks. The window into the nesting cavity shows one of the young with its mouth open ready to receive the food.

This is, of course, the ultimate goal of all this combat and feeding trips. A young bird, still in its downy plumage, has crept up to the entrance of the nesting hole for a look at the outside world.