Ardea nycticorax Linnaeus, 1758, Europe. Four subspecies
OTHER COMMON NAMES
English: Night heron; French: Bilhoreau gris; German: Nachtreiher; Spanish: Martinete.
A stocky dark gray and white heron with a distinctive glossy black bill, crown, and back. Length is 22–25.5 in (56–65 cm); weight is 18.5–28 oz (525–800 g). During breeding it develops white head plumes that may reach 10 in (25 cm) long. It has relatively short legs that do not extend much beyond the tail when in flight. Juveniles are cryptic gray-brown with buff and white spots above and stripes below.
Occurs across the temperate and tropical world from North and South America, Europe, Africa, and Asia to the East Indies.
Typically found along the vegetated margins of shallow freshwater or brackish rivers, streams, ponds, lakes, marshes, swamps, mangroves, and mud flats. Also uses grasslands and coastal habitats, especially on migration, and unlike most herons occurs on high mountains. Uses pastures, ponds, reservoirs, canals, ditches, fishponds, rice fields, wet-crop fields, and dry grasslands. Usually nests in bushes and trees but also in reeds, sedge, grass tussocks, on the ground in protected areas like islands, and in protected locations in urban areas. Large nesting colonies especially appear to be associated with protected sites in large wetlands.
A noisy bird having a raucous “quawk” call. Also has a breeding call that is like the sound of a rubber band being plunked and followed by a buzz or hiss. It flies with wing beats that are faster than most herons. Roosts by day in trees and bushes and is most often seen flying to roost in the morning and out in the evening, giving the quawk call. Roosts commonly are in rural areas and within towns.
FEEDING ECOLOGY AND DIET
Typically feeds at night, locating prey by sight and sound, also feeds during the day when nesting. Usual method is standing in a crouched posture and making a lunging strike at prey. During daylight, it may run, dive into the water from the air, hover, swim, or use its wings to startle prey. Also attracts fish by vibrating its bill or using baits. Mostly a solitary forager, maintaining territories that it defends vigorously. Also feeds in aggregations when prey is highly concentrated. Fish, frogs, and aquatic insects predominate in the diet. Often eats the young of other colonial nesting waterbirds.
In temperate areas, nesting occurs in spring, often early, but in tropical and subtropical areas nesting is more variable. The species often nests in rural, suburban, and urban settings, particularly in zoos. Nesting is usually colonial, in single- species or mixed-species colonies that number sometimes in the thousands. Nests are a platform of sticks and reeds, 12–18 in (30–45 cm) wide. Eggs are green to pale bluegreen. Clutch size is two to five eggs with an overall range of one to seven. Incubation averages 23 days. Parents brood the young for 10 days. The young clamber out of the nest by three weeks and fledge in six or seven weeks. Nesting success is often high.
Not threatened. However, nesting is limited to few areas in some regions, such as in Europe, so conservation of these sites is crucial. In North America, populations declined due to pesticides, particularly up to the 1960s.
SIGNIFICANCE TO HUMANS
Fairly tolerant of human activities, and often nest and roost near humans. Night herons are often killed at fish hatcheries and are still hunted for food in some places. Most human interaction has been positive for the species.
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