Spokane, WA, United States
Violet-green swallows have been nesting in my yard for 15 years. Occasionally, a fledgling will return to the nest box for a few minutes to be fed. This year, however, two of them returned to the nest box and stayed overnight and most of the following day before leaving a second time. This is one of the young that returned.
I have never seen this behavior before in violet-green swallows.