Black-crowned Night Heron
Encyclopedia
The Black-crowned Night Heron (Nycticorax nycticorax; ) commonly abbreviated to just Night Heron in Eurasia
, is a medium-sized heron
found throughout a large part of the world, except in the coldest regions and Australasia
(where replaced by the closely related Rufous Night Heron, with which it has hybridized in the area of contact).
s throughout much of the world. The subspecies N. n. hoactli breeds in North
and South America
from Canada
as far south as northern Argentina
and Chile
, N. n. obscurus in southernmost South America, N. n. falklandicus in the Falkland Islands
, and the nominate race N. n. nycticorax in Europe
, Asia
and Africa
. Black-crowned Night Herons nest in colonies
on platforms of sticks in a group of trees, or on the ground in protected locations such as islands or reedbeds. Three to eight egg
s are laid.
This heron is migratory
in the northernmost part of its range, but otherwise resident (even in the cold Patagonia
). The North American population winters in Mexico
, the southern United States
, Central America
, and the West Indies, and the Old World
birds winter in tropical Africa and southern Asia.
, crustacean
s, frog
s, aquatic insect
s, small mammals and small birds. During the day they rest in trees or bushes. N. n. hoactli is more gregarious outside the breeding season than the nominate race.
-like call.
In the Falkland Islands
, they are known as "quarks", which is an onomatopoeic term.
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
, is a medium-sized heron
Heron
The herons are long-legged freshwater and coastal birds in the family Ardeidae. There are 64 recognised species in this family. Some are called "egrets" or "bitterns" instead of "heron"....
found throughout a large part of the world, except in the coldest regions and Australasia
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
(where replaced by the closely related Rufous Night Heron, with which it has hybridized in the area of contact).
Description
Adults are approximately 64 cm (25.2 in) long and weigh 800 g (28.2 oz). They have a black crown and back with the remainder of the body white or grey, red eyes, and short yellow legs. Young birds are brown, flecked with white and grey. These are short-necked and stout herons.Distribution
The breeding habitat is fresh and salt-water wetlandWetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s throughout much of the world. The subspecies N. n. hoactli breeds in North
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
from Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
as far south as northern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
and Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, N. n. obscurus in southernmost South America, N. n. falklandicus in the Falkland Islands
Falkland Islands
The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...
, and the nominate race N. n. nycticorax in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
and Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Black-crowned Night Herons nest in colonies
Bird colony
A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony...
on platforms of sticks in a group of trees, or on the ground in protected locations such as islands or reedbeds. Three to eight egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s are laid.
This heron is migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
in the northernmost part of its range, but otherwise resident (even in the cold Patagonia
Patagonia
Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...
). The North American population winters in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, the southern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
, and the West Indies, and the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
birds winter in tropical Africa and southern Asia.
Behaviour
These birds stand still at the water's edge and wait to ambush prey, mainly at night or early morning. They primarily eat small fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, aquatic insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, small mammals and small birds. During the day they rest in trees or bushes. N. n. hoactli is more gregarious outside the breeding season than the nominate race.
Etymology
The scientific name, Nycticorax, means "night raven", and refers to this species' nocturnal habits and harsh crowCrow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
-like call.
In the Falkland Islands
Falkland Islands
The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...
, they are known as "quarks", which is an onomatopoeic term.
External links
- Cornell Lab of Ornithology - Black-crowned Night-Heron Information
- USGS Patuxent Bird Identification InfoCenter - Black-crowned Night-Heron
- South Dakota Birds and Birding - Black-crowned Night-Heron Information and Photos
- eNature.com - Black-crowned Night-Heron
- Field Guide on Flickr
- Images and information of Black-crowned Night-Heron from Portugal