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Photo © Keith Williams
Photo © Ian Stewart

Tree Swallows Share Nest

NestWatcher Ian Stewart discovered something unusual in a nest box in Greenville, Delaware, this past season. Two female Tree Swallows laid their eggs in the same box, for a whopping total of 10 eggs! Instead of abandoning this full house, both females stayed to incubate the eggs and feed the young. Because both adult females were banded and captured in the box, we can say with certainty that they both helped to rear the young.

All 10 eggs did hatch, although the last one was one or two days later than the others and did not make it. Several weeks later, nine baby Tree Swallows fledged from this nest box, a remarkable outcome for a nest that, under different circumstances, may have been abandoned by both females. See more photos from Ian here. While you’re there, share your own photos and stories about the wonderful birds that you met while NestWatching.

Cornell Lab of Ornithology

Cornell Lab of Ornithology