Tree Swallow Response to Habitat Quality

Allison M. Bernhisel shares a research update examining how habitat quality influences Tree Swallow health.  

This summer, we partnered with researchers from the University of Montana to measure the health and reproductive success of birds at MPG North.

By studying the health and reproductive success of birds, we can learn whether our restoration work has translated into habitat improvements that benefit wildlife.

Dr. Creagh Breuner (above) leads the Tree Swallow research.

Dr. Breuner measures nest success by observing how many nests are built and how long birds take to build them. Then, she counts and weighs the offspring and determines how many of the young survive until they can fly on their own.

Seven eggs began hatching on June 18 (A). Within five days, hatching had ceased and nestlings began begging for food (B).

Dr. Breuner collected these one-day old nestlings from their nest box. She then measured, marked, and returned them to their nest.

Nestlings develop rapidly. These 12-day old nestlings, though covered with more feathers and fat, are still blind and will depend on their parents for a few more days.

We found 18 attempted nests this summer, 14 of them with eggs and/or nestlings. One of the two abandoned nests failed early and a pair of Tree Swallows—potentially the same pair—built a new nest on top of it.

Once the young can stay warm on their own (at about 15 days), Dr. Breuner captures the parents to evaluate their health.

Dr. Breuner will continue collecting data until the last nestlings leave their nest.

ee Swallows are not the only critters using the nest boxes. Here, a red squirrel pokes its head out for a quick gander.