Most involved at dusk or at night are the black-crowned night heron (Nycticorax nycticorax), or black-capped night heron, their ghostly forms flying from their daytime roosts to the wetlands where they forage. A medium-sized heron found in most of the world, except in the coldest regions and Australasia (where it is replaced by the closely related rufous night heron with which it has hybridized in the field of contact) is generally shortened to known as “night heron” in Eurasia. It has a stocky look, the head tucked down into the shoulders, as if hunched over, and it is usually seen with this stance. It has much shorter legs and neck than other herons. Small herons with very squat, dense proportions are Black-crowned Night-Herons. They’ve got thick necks, large, flat heads, and pointed heavy bills. The wings are rounded and long. Some reports say they eat at night since other herons and egrets dominate them by day. This species resides in a wide variety of wetlands that are dry, salty, or brackish, and is the world’s most common heron. Adults are light-gray birds with a black back and a black crown that is neatly defined. Immatures are brown with broad white spots on the wings and on the underparts with blurry stripes. All-black bills have adults; yellow-and-black bills have immature ones. They are comparatively stocky with shorter bills, legs, and heads than the egrets and “day” herons, their more famous relatives. Normally, their resting posture is somewhat hunched, but they stretch their necks while hunting and appear more like other wading birds. Night-Herons, black-crowned, frequently spend their days perched on tree limbs or hidden between leaves and branches. In the evening and at night, they drill in the sea, on the mudflats, and on the ground. They fold their heads back against their shoulders in flight, almost making their necks vanish. The young birds have orange eyes and yellowish-green legs that are duller. In their nesting colonies, they are very noisy birds, with calls that are usually transcribed as quok or woc.
(Black-Crowned Night Heron)
These are social birds who, although they usually forage on their own, prefer to roost and nest in groups. Look for them, including estuaries, marshes, streams, dams, and reservoirs, in most wetland ecosystems in North America. The first breeds are typically at the age of 2 years. Breed in colonies, alone or mixed with other herons, egrets, ibises, often with Franklin’s Gulls, of this genus. For some decades, several colonies have been occupied. It may start nesting earlier than other herons in the season. Tiny fish, crustaceans, frogs, aquatic insects, small mammals, and small birds are mainly eaten. They are among the seven species of herons observed to engage in bait fishing; an unusual example of tool usage among birds is luring or distracting fish by tossing edible or inedible buoyant items into water within their striking range. It can retract its feet on cold days while flying in order to conserve heat. Young people abandon their perches in the nest when it’s cold to huddle. The feeding and breeding territories of a Black-crowned night heron will be defended. Young people can be violent toward human intruders, defecating, or regurgitating. On cliff ledges or reed beds, tall trees, bushes, or on the ground, nests are made. 3-5 eggs are laid and can produce two broods per season. It takes between 21-22 days for incubation and both parents brood their young ones. Via regurgitation, both parents feed young herons. At 4 weeks, young clamber around in the nest tree, able to fly at about 6 weeks. Parents can follow parents to foraging areas after 6-7 weeks and beg to be fed there. While black-crowned night herons are relatively abundant and widespread, localized threats, especially habitat loss, wetland destruction, contamination of petroleum and pesticides, hunting, and disease, are a concern for certain populations.