sanderlings

One large sea gull stood on the beach as I started my walk at the Parker River National Wildlife Refuge yesterday. It stood, it walked a bit, then it flew off leaving me on the beach without any bird companions.

I walked a bit further before encountering a large flock of sanderlings. These small birds have always fascinated me as they run down the beach, running in one direction then changing direction as a group. Do some of their chirps signal direction changes? I'd love to know how they communicate with each other.