Black-crowned night-herons are social birds
The scientific name of the black crowned night heron (Nycticorax nycticorax) means "night raven" in Latin, indicative of its mostly nocturnal activity and loud squawk similar to that of a crow or raven. They are short, stocky birds. The adults have black caps and backs, gray wings, and white under parts; the young are brown with streaked under parts.
The eyes of this adult heron are bright red. Black crowned night herons have a hunchback appearance when standing still. This heron is a very social bird, often living and breeding in large colonies. It has the widest distribution of any heron, found throughout the globe, nesting on every continent except Antarctica and Australia. Like all herons, the black crowned night heron is a wading bird in both fresh and saltwater. This bird stands still by the water's edge and ambushes its prey, which often includes fish, frogs, crustaceans, birds and small mammals.
They typically rest during the day and feed at night, often taking the place of "day herons" that have retired to their resting places. The exception is that they are active pretty much all day while rearing their young. The male builds elaborate nests to attract potential mates and a female will often take in orphan herons and raise them with her brood.
Black crowned night herons have nested in the tall pines and spruce at the west end of Culler Lake in Frederick since about 2005. Last year there were at least six nests. The birds arrive in our area toward the end of March and remain until mid-September.
Young birds vocalize, especially when the adults arrive with food. The adults appear to travel some distance to find food. Although their diet consists mainly of fish and frogs, one bird was spotted swallowing a baby grackle and others have caught ducklings.
Dave Wallace, of the Frederick Bird Club, contributed to this article.
Nature Notes for 2/5/2012