I observed three Bushtit nests along the Audubon Trail and Connected Lakes area this spring in Grand Junction. I look for pairs in late winter establishing territories, then try to find their nests as they are building them and the leaves are off the trees. They build their nests in March/April and it takes some time to complete the long, gourd-shaped sock like nests. Often the pair will complete the nest and then wait before nesting. Seems to me they wait till things leaf out (making the nests very difficult to find) before nesting.
Of the 3 nests I observed this spring, two were in low hanging cottonwood branches and one in a large sagebrush. Two were about 5 feet off the ground and one was up about 20-25 feet.
Nest #1 in sagebrush about 5 feet off the ground. Last date I observed activity at the nest was 5-08. Lots of activity prior to that.
Nest #2 about 25 feet off ground in low hanging cottonwood branch. Birds left nest the morning of 5-16. I went back that same evening to see if the family returned to the nest, and did not see them. Have seen the family flock several times since in the general vicinity.
Nest #3 was about 5 feet off the ground in a low hanging cottonwood branch. Both birds were seen on May 1 working on nest after a period of time in which I had not see them. This nest suffered predation by a raccoon or another bird on May 4 or 5th. I saw both birds at the nest on the morning of May 4, and discovered the destroyed nest mid-day on May 5.
Several years ago I watched Bushtits build their nest in a Box Elder tree in Bear Creek Lake Park. As I recall, those birds were finished nesting sometime after the first week of May.
Probably more then you wanted to know, but they are fascinating little birds. Brought lots of caterpillars to their nests.
Mike Henwood
Grand Junction