Last night in Bath, Maine I heard thrushes migrating in the dark. As they fly they make short contact calls to keep the flock together. Among the calls, I was able to identify two species.
The first call was plentiful and sounded like the single note of a spring peeper. Those were Swainson's thrushes (above). Click here to hear the peep sound at the beginning of the recording.
The second sound was less frequent. There were fewer of this species, their call note lasted longer and descended roughly. By listening at the Macaulay Library online I determined they were gray-cheeked thrushes (below). Click here to hear.
Last night the birds were on the move while the weather was good. Today will be hot. Tonight will be stormy.
(photos by Shawn Collins)