Coastal Watch, Part 5 - Birds at Rest

Purple sandpipers at tideline

In midwinter as the tide drops below its midline you may come across Purple sandpipers foraging in the Irish moss and dashing down between receding waves. Small flocks of them go winging off suddenly for undisclosed reasons. When the ocean reclaims the intertidal zone the birds go off to rest.

Far down the shore in the direction I'm walking I notice an incongruous bump on the silhouette of a boulder. It hasn't moved during my approach, even as I set up the camera on a tripod.

Purple sandpiper resting

A sandpiper has tucked itself into a fluffy ball. Its eyes flutter open and closed every few seconds. Is my intrusion keeping the bird awake? Exposed as it is, vigilant watching for merlins and peregrine falcons seems prudent. Those eyes should never close too long.

Sanderlings

At rest a sandpiper economizes energy by bringing one leg up to its body and turning its bill back within its wings.

Mallards

Mallards in a similar posture can close both eyes. They feel more secure snoozing among nearby ducks that stay alert for danger.

Horned grebes

Grebes sleep with their plumage fluffed for insulation and their bills tucked forward beneath chest feathers.

Harlequin ducks

Harlequin ducks roost periodically outside the tumultuous surf where they spend most of the day. Some this group have at least one eye closed. It's possible they sleep uni-hemispherically, that is, resting half their brain at a time. Ornithological researchers have proven that some birds are able to do this on long flights while the other half of the brain navigates and maintains watch.