All About the Black-crowned Night Heron
Black-crowned Night-Herons breed in colonies with other night-herons and commonly mix with other wading bird species such as Snowy Egret, Tricolored Heron, Great Egret, and Glossy Ibis. They can be found in social groups all year round.
During this courtship period, the legs of both males and females turn a light pink color and the specialized plume feathers on their head are especially prominent.
Night-herons can recognize their mates, most likely through individual voice characteristics. To us, male and female night-herons look the same but behavior can give us some clues as to who is who in a pair. For example, males select a nest location and attract females to the site. He starts the construction process and then brings sticks to his mate for her to add to the nest. To tell the difference between individuals, researcher may mark birds with uniquely numbered bands on their legs. Pairs tend to stay together during a breeding season but it is not known whether the same pair reforms from year to year.
Eggs are a greenish-blue color, and 3-5 eggs complete a clutch. Parents incubate the eggs for around 25 days before the young hatch. The young are protected (or brooded) by parents to help regulate their temperature and protect them from predators.
Males and females both incubate their eggs and later care for their young. They each make multiple trips a day to find food which they bring back to the nest to feed their chicks.
Disturbance from people near colonies can cause night-herons to abandon their nest and young, and can also increase chances of predation.
Unlike long-legged wading birds, this species rests in trees during the day and forages once the sun goes down. Their croaking call is a familiar sound at sunset when the night-herons depart their daytime roosts to search for prey.
They can be found year-round in New Jersey but can be hard to detect, especially during the non-breeding season when they aren’t busy taking care of young.
Black-crowned Night-Herons breed on every continent except Australia and Antarctica. They closely associate with wetlands of all varieties – fresh, brackish, and salt water. With this tight habitat association and because they consume fish and other freshwater and marine organism, Black-crowned Night-Herons are good indicators of wetland quality and contamination