Tuesday, March 26, 2013

Horned Grebes

This morning, a pair of horned grebes rippled the calm, gray waters of Sandy Lake, southeast of Kent.  While the landscape of northeastern Ohio retains the look and feel of winter, these avian visitors were evidence that spring is gradually unfolding, however reluctant it may seem.

Indeed, horned grebes summer on freshwater streams, ponds and wetlands from southern Alaska to east-central Canada, including the northernmost tier of the American Great Plains.  Come fall, they head for saltwater bays and brackish rivers of the Pacific and Southeastern Coasts; a minority may also be encountered on southern freshwater lakes.  There and during their migrations, they are adorned in their black and white winter plumage, molting to their more colorful breeding plumage once back in their northern homeland.  Like pied-billed grebes but unlike western and eared grebes, horned grebes are rarely found in sizable flocks; rather, these small, stocky birds are usually seen alone, in pairs or in small groups.

Diving for small fish, aquatic invertebrates and insects, horned grebes are able to remain underwater for several minutes.  Floating nest platforms of dead vegetation are anchored to emergent marsh plants and 3-6 eggs are generally produced; both parents rear the youngsters which, like those of other grebe species, often ride on their backs until fledged.  Of special interest, horned grebes are known to consume some of their own feathers (and feed some to their young); ornithologists believe that this gastric plug retains small fish bones until they are more thoroughly digested.