• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Difference between revisions of "Black-crowned Night Heron" - BirdForum Opus

(Juvenile flight picture)
(more details)
Line 1: Line 1:
[[Image:Black-crowned_Night_Heron.jpg|thumb|550px|right|Subspecies: ''N. n. hoactli''<br/>Photo by {{user|Gene|Gene}}<br/>[[Illinois]], [[USA]], May 2004]]  
+
[[Image:Night Heron, Brenne, France.jpg|thumb|550px|right|''N. n. nycticorax'', adult<br/>Photo by {{user|Joelle-Marcelle|Joelle-Marcelle}}<br/>Brenne, [[France]], May 2015]]
 
;[[: Category:Nycticorax|Nycticorax]] nycticorax
 
;[[: Category:Nycticorax|Nycticorax]] nycticorax
  
 
==Identification==
 
==Identification==
64 cm (25 in)<br />
+
[[Image:Black-crowned_Night_Heron.jpg|thumb|350px|right|''N. n. hoactli'', adult<br/>Photo by {{user|Gene|Gene}}<br/>[[Illinois]], [[USA]], May 2004]]
Short-necked, rather stout birds<br />
+
Length 51-70 cm (25 in), wingspan 100-112 cm, weight 520-800 g<br />
 +
A medium-small, rather stout heron, looking stocky and short-necked when at rest<br />
 
'''Adult'''
 
'''Adult'''
*Black crown and back
+
*Black crown, lores, and back
*Rest of body white or gray
+
*Narrow white forehead
*Red eyes
+
*Two slender white plumes on the rear of the head in the breeding season
*Short yellow legs
+
*Eye bright red
[[Image:KvakacJuv 8445.jpg|thumb|350px|right|Photo by {{user|mikemik|mikemik}}<br />Hrase, [[Slovenia]], August 2015]]
+
*Bill black in breeding season, often with yellowish-grey base in rest of year
'''Young''' birds are brown, with white and gray flecks
+
*Rest of body white or pale grey below
 +
*Wings and tail dark grey
 +
*Short yellow legs, becoming bright pink to red during courtship in spring
 +
[[Image:Falklands Night Heron.jpg|thumb|350px|right|''N. n. falklandicus'', adult<br/>Photo by {{user|cranstall|cranstall}}<br />Pebble Island, [[Falkland Islands]], January 2015]]
 +
'''First-year''' young birds
 +
*Dark brown above, paler brown below, with white to pale buffy-brown teardrop marks on all feather tips
 +
*Legs duller, often greenish- or greyish-yellow
 +
*Eye yellowish to orangey
 +
*Bill with yellowish-grey base
 +
'''Second year''' subadult birds
 +
*Similar to adult, except dark grey-brown where adult is black, and breast streaked dark grey
 +
*Bill black or with yellowish-grey base
 +
 
 +
====Similar species====
 +
Adults are very distinctive, with few confusion possibilities. [[Rufous Night Heron]] overlaps locally in southeast [[Asia]]; it differs in being reddish-brown where Black-crowned is dark grey. In [[South America]], the [[Boat-billed Heron]] has a similar plumage pattern, but is smaller and with an obviously large, swollen bill.
 +
 
 +
Juveniles are more easily confused with other brown herons; [[:Category:Botaurus|''Botaurus'' bitterns]] are markedly larger, while juvenile [[:Category:Ixobrychus|''Ixobrychus'' bitterns]] are smaller. Young [[Yellow-crowned Night Heron]] in the Americas is the most easily confused; it differs in being longer-legged, duller brown with smaller pale teardrop marks, and thicker-billed.
 +
 
 
==Distribution==
 
==Distribution==
 +
[[Image:KvakacJuv 8445.jpg|thumb|350px|right|''N. n. nycticorax'', juvenile<br />Photo by {{user|mikemik|mikemik}}<br />Hrase, [[Slovenia]], August 2015]]
 +
Near cosmopolitan, throughout warmer areas of [[Europe]], [[Africa]], [[Asia]], [[North America|North]], [[Central America|Central]], and [[South America]]. Missing from [[Australasia]], where it is replaced by the closely related [[Rufous Night Heron]], and Antarctica.
 +
====Europe====
 +
Patchy breeding range across southern and central Europe from [[Iberia]] to [[Greece]] and [[Turkey]], and north to [[France]], the [[Netherlands]], and [[Russia]]. Its range is currently expanding slowly north following better protection, with the first modern breeding record in [[Britain]] in 2017.
 +
 +
[[Image:Night Heron 2nd year.jpg|thumb|350px|right|''N. n. nycticorax'', 2nd year<br />Photo by {{user|Cristian+Mihai|Cristian Mihai}}<br />Chitila, Ilfov, [[Romania]], June 2013]]
 +
It is a summer visitor to all its European range, with birds migrating to subsaharan Africa in winter. Overshooting spring migrants are regularly seen in Britain (>500 records), usually May-June, more rarely north to [[Iceland]] and the [[Faroe Islands|Faroes]], [[Norway]], [[Finland]], and [[Estonia]]. Also recorded on the [[Azores]], [[Madeira]], and [[Cape Verde Islands]].
 +
 +
There are also feral colonies in [[Belgium]] which are the descendants of released birds, and formerly also in Norfolk, [[England]] and around Edinburgh Zoo, [[Scotland]] (the latter were of the subspecies ''N. n. hoactli'').
  
[[North America|North]], [[Central America|Central]], and [[South America]], [[Europe]], [[Africa]], and [[Asia]].  
+
====Asia====
 +
In Asia breeds from the Caspian east to [[China]] and [[Japan]] and south to [[India]] and [[Sri Lanka]], [[Malaya]], [[Borneo]] and [[Sumatra]]. Birds in central Asia are migratory, those in southern Asia are resident.
 +
====Africa & Middle East====
 +
Widespread in subsaharan Africa from [[Senegal]] to [[Somalia]] and south to the Cape but breeding records are widely scattered. Also small numbers in northwest Africa, the Nile Delta and parts of the [[Middle East]].
 
====Americas====
 
====Americas====
 
Breeds in south-central and south-eastern [[Canada]] and over much of the [[USA]] except the mountains of the west. Also occurs in the [[West Indies]] and from [[Mexico]] south to [[Panama]] and over most of South America except the higher Andes and Amazonia. Also breeds in the [[Falkland Islands]] and [[Hawaii]]. Northern birds are migratory and winter in south-west and south-east USA.
 
Breeds in south-central and south-eastern [[Canada]] and over much of the [[USA]] except the mountains of the west. Also occurs in the [[West Indies]] and from [[Mexico]] south to [[Panama]] and over most of South America except the higher Andes and Amazonia. Also breeds in the [[Falkland Islands]] and [[Hawaii]]. Northern birds are migratory and winter in south-west and south-east USA.
====Europe====
 
Very patchy breeding range across southern Europe from [[Iberia]] to [[Greece]] and [[Turkey]], and north to [[Russia]]. Isolated breeding population in the [[Netherlands]].
 
  
Colony of full-winged, but artificially fed, birds of the nominate race breeds ferally in Norfolk, [[England]] and there is a small number of free-flying birds of the North American race based around Edinburgh Zoo, [[Scotland]]. Neither of these populations is thought to wander any distance and attempts are underway to reduce the number of free-flying birds in the Scottish population.
 
[[Image:Black-crowned Night-Heron11.jpg|thumb|350px|right|Photo by {{user|linesiam|linesiam}}<br />Bangpu, [[Thailand]], March 2009 ]]
 
There are also colonies in [[Belgium]] which are the descendants of released birds. A summer visitor to all but the south-east of the region where resident, overshooting spring migrants regularly seen in Britain (>500 records), usually May-June, more rarely north to [[Iceland]] and the [[Faroe Islands|Faroes]], [[Norway]], [[Finland]], and [[Estonia]]. Also recorded on the [[Azores]], [[Madeira]], and [[Cape Verde Islands]].
 
====Asia====
 
In Asia breeds from the Caspian east to [[China]] and [[Japan]] and south to [[India]] and [[Sri Lanka]], [[Malaya]], [[Borneo]] and [[Sumatra]].
 
====Africa/Middle East====
 
Widespread in sub-Saharan Africa from [[Senegal]] to [[Somalia]] and south to the Cape but breeding records are widely scattered. Also small numbers in North-West Africa, the Nile Delta and parts of the [[Middle East]].
 
 
==Taxonomy==
 
==Taxonomy==
[[Image:KvakacJuvLeti 8972.jpg|thumb|350px|right|Juvenile<br />Photo by {{user|mikemik|mikemik}}<br />Hrase, [[Slovenia]], Aug 2015]]
 
 
====Subspecies====
 
====Subspecies====
Four subspecies are recognised<sup>[[#References|[1]]]</sup>:
+
[[Image:Black-crowned Night-Heron11.jpg|thumb|350px|right|''N. n. nycticorax'', adult in flight<br/>Photo by {{user|linesiam|linesiam}}<br />Bangpu, [[Thailand]], March 2009]]
*''N. n. nycticorax'' (Eurasian):
+
Four subspecies are recognised<sup>[[#References|[1]]]</sup><sup>[[#References|[2]]]</sup>:
 +
*''N. n. nycticorax'':
 
:*[[Eurasia]] south to [[Indonesia]], [[Africa]] and [[Madagascar]]
 
:*[[Eurasia]] south to [[Indonesia]], [[Africa]] and [[Madagascar]]
*''N. n. hoactli'' (American);
+
*''N. n. hoactli'':
:*Southern [[Canada]] to northern [[Argentina]] and [[Chile]], and the [[West Indies]] ([[Greater Antilles]])
+
:*Southern [[Canada]] to northern [[Argentina]] and [[Chile]], the [[West Indies]] ([[Greater Antilles]]), and [[Hawaii]]
 
*''N. n. obscurus'':
 
*''N. n. obscurus'':
 
:*Lowland northern [[Chile]] and north-central [[Argentina]] to [[Tierra del Fuego]]
 
:*Lowland northern [[Chile]] and north-central [[Argentina]] to [[Tierra del Fuego]]
*''N. n. falklandicus'' (Falklands):
+
*''N. n. falklandicus'':
 
:*[[Falkland Islands]]
 
:*[[Falkland Islands]]
 +
 +
The subspecies differ mainly in breast darkness, with ''N. n. hoactli'' the palest, ''N. n. nycticorax'' intermediate, and ''N. n. obscurus'' and ''N. n. falklandicus'' the darkest, dusky grey below. Some authorities treat ''N. n. falklandicus'' as a synonym of ''N. n. obscurus''<sup>[[#References|[3]]]</sup>.
 
==Habitat==
 
==Habitat==
 
Wooded swamps, well-vegetated margins of lakes and rivers.  On passage and in winter sometimes in more open habitats, including brackish lagoons and estuaries.
 
Wooded swamps, well-vegetated margins of lakes and rivers.  On passage and in winter sometimes in more open habitats, including brackish lagoons and estuaries.
 
==Behaviour==
 
==Behaviour==
Usually [[Dictionary_A-C#C|Crepuscular]].  
+
Usually [[Dictionary_A-C#C|crepuscular]].  
 
====Diet====
 
====Diet====
 
An opportunistic feeder, their very varied diet consists of fish, and shellfish, leeches, earthworms, insects, amphibians, reptiles, such as lizards and snakes, turtles, rodents, birds, and their eggs. They also eat plants, carrion and forage at landfill sites.
 
An opportunistic feeder, their very varied diet consists of fish, and shellfish, leeches, earthworms, insects, amphibians, reptiles, such as lizards and snakes, turtles, rodents, birds, and their eggs. They also eat plants, carrion and forage at landfill sites.
Line 51: Line 74:
 
''[[Media:Nycticorax nycticorax (song).mp3|Listen in an external program]]''
 
''[[Media:Nycticorax nycticorax (song).mp3|Listen in an external program]]''
 
==References==
 
==References==
#{{Ref-Clements6thAug15}}#Alvaro Jaramillo. 2003. Birds of Chile. Princeton Field Guides. ISBN 0-691-11740-3
+
#{{Ref-Clements6thAug17}}#{{Ref-GillDonsker17V7.3}}#{{Ref-HBWVol1}}#Alvaro Jaramillo. 2003. Birds of Chile. Princeton Field Guides. ISBN 0-691-11740-3
 
#Handbook of the Birds of the World Alive (retrieved August 2015)
 
#Handbook of the Birds of the World Alive (retrieved August 2015)
 
#surfbirds
 
#surfbirds

Revision as of 17:01, 12 November 2017

N. n. nycticorax, adult
Photo by Joelle-Marcelle
Brenne, France, May 2015
Nycticorax nycticorax

Identification

N. n. hoactli, adult
Photo by Gene
Illinois, USA, May 2004

Length 51-70 cm (25 in), wingspan 100-112 cm, weight 520-800 g
A medium-small, rather stout heron, looking stocky and short-necked when at rest
Adult

  • Black crown, lores, and back
  • Narrow white forehead
  • Two slender white plumes on the rear of the head in the breeding season
  • Eye bright red
  • Bill black in breeding season, often with yellowish-grey base in rest of year
  • Rest of body white or pale grey below
  • Wings and tail dark grey
  • Short yellow legs, becoming bright pink to red during courtship in spring
N. n. falklandicus, adult
Photo by cranstall
Pebble Island, Falkland Islands, January 2015

First-year young birds

  • Dark brown above, paler brown below, with white to pale buffy-brown teardrop marks on all feather tips
  • Legs duller, often greenish- or greyish-yellow
  • Eye yellowish to orangey
  • Bill with yellowish-grey base

Second year subadult birds

  • Similar to adult, except dark grey-brown where adult is black, and breast streaked dark grey
  • Bill black or with yellowish-grey base

Similar species

Adults are very distinctive, with few confusion possibilities. Rufous Night Heron overlaps locally in southeast Asia; it differs in being reddish-brown where Black-crowned is dark grey. In South America, the Boat-billed Heron has a similar plumage pattern, but is smaller and with an obviously large, swollen bill.

Juveniles are more easily confused with other brown herons; Botaurus bitterns are markedly larger, while juvenile Ixobrychus bitterns are smaller. Young Yellow-crowned Night Heron in the Americas is the most easily confused; it differs in being longer-legged, duller brown with smaller pale teardrop marks, and thicker-billed.

Distribution

N. n. nycticorax, juvenile
Photo by mikemik
Hrase, Slovenia, August 2015

Near cosmopolitan, throughout warmer areas of Europe, Africa, Asia, North, Central, and South America. Missing from Australasia, where it is replaced by the closely related Rufous Night Heron, and Antarctica.

Europe

Patchy breeding range across southern and central Europe from Iberia to Greece and Turkey, and north to France, the Netherlands, and Russia. Its range is currently expanding slowly north following better protection, with the first modern breeding record in Britain in 2017.

N. n. nycticorax, 2nd year
Photo by Cristian Mihai
Chitila, Ilfov, Romania, June 2013

It is a summer visitor to all its European range, with birds migrating to subsaharan Africa in winter. Overshooting spring migrants are regularly seen in Britain (>500 records), usually May-June, more rarely north to Iceland and the Faroes, Norway, Finland, and Estonia. Also recorded on the Azores, Madeira, and Cape Verde Islands.

There are also feral colonies in Belgium which are the descendants of released birds, and formerly also in Norfolk, England and around Edinburgh Zoo, Scotland (the latter were of the subspecies N. n. hoactli).

Asia

In Asia breeds from the Caspian east to China and Japan and south to India and Sri Lanka, Malaya, Borneo and Sumatra. Birds in central Asia are migratory, those in southern Asia are resident.

Africa & Middle East

Widespread in subsaharan Africa from Senegal to Somalia and south to the Cape but breeding records are widely scattered. Also small numbers in northwest Africa, the Nile Delta and parts of the Middle East.

Americas

Breeds in south-central and south-eastern Canada and over much of the USA except the mountains of the west. Also occurs in the West Indies and from Mexico south to Panama and over most of South America except the higher Andes and Amazonia. Also breeds in the Falkland Islands and Hawaii. Northern birds are migratory and winter in south-west and south-east USA.

Taxonomy

Subspecies

N. n. nycticorax, adult in flight
Photo by linesiam
Bangpu, Thailand, March 2009

Four subspecies are recognised[1][2]:

  • N. n. nycticorax:
  • N. n. hoactli:
  • N. n. obscurus:
  • N. n. falklandicus:

The subspecies differ mainly in breast darkness, with N. n. hoactli the palest, N. n. nycticorax intermediate, and N. n. obscurus and N. n. falklandicus the darkest, dusky grey below. Some authorities treat N. n. falklandicus as a synonym of N. n. obscurus[3].

Habitat

Wooded swamps, well-vegetated margins of lakes and rivers. On passage and in winter sometimes in more open habitats, including brackish lagoons and estuaries.

Behaviour

Usually crepuscular.

Diet

An opportunistic feeder, their very varied diet consists of fish, and shellfish, leeches, earthworms, insects, amphibians, reptiles, such as lizards and snakes, turtles, rodents, birds, and their eggs. They also eat plants, carrion and forage at landfill sites.

Breeding

It builds a platform of sticks placed in tree or cattails and nests colonially; more than a dozen nests may be in a single tree. Clutch usually consists of 3-5 greenish eggs.

Vocalisation

<flashmp3>Nycticorax nycticorax (song).mp3</flashmp3>
Listen in an external program

References

  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2017. The eBird/Clements checklist of birds of the world: v2017, with updates to August 2017. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
  2. Gill, F. and Donsker, D. (Eds). 2017. IOC World Bird Names (version 7.3). Available at http://www.worldbirdnames.org/.
  3. Del Hoyo, J, A Elliot, and J Sargatal, eds. 1992. Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Barcelona: Lynx Edicions. ISBN 978-8487334108
  4. Alvaro Jaramillo. 2003. Birds of Chile. Princeton Field Guides. ISBN 0-691-11740-3
  5. Handbook of the Birds of the World Alive (retrieved August 2015)
  6. surfbirds
  7. All About Birds
  8. Wikipedia

Recommended Citation

External Links


Back
Top