''Gorsachius'' is a genus of Old World night herons typically found near water in forested regions. These are medium-sized

heron Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 75 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus ''Botaurus'' are referred to as bi ...

s which are migratory in the colder parts of their ranges, but otherwise resident. They are the least known, most strictly

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

, smallest and overall rarest night herons. They are found in

East East is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the fact that ea ...

South South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both west and east. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...

and

South-east Asia Southeast Asia is the geographical southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Australian mainland, which is part of Oceania. Southeast Asia i ...

. Both species resemble each other, being relatively short-billed and overall brown with a dark line from the throat to the upper belly. Their behavior is relatively poorly known compared to that of other night herons, but they nest alone or in small groups, and a clutch of two to five

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

s has been recorded. While generally nocturnal and

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal (active during dawn), vespertine (biology), vespertine/vespertinal (active during dusk), or both. This is distinguished from diurnalit ...

, they have been recorded feeding during the day in clouded weather. They are skulking, and known to feed on crabs,

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

, fish, insects, frogs and other small animals.

Taxonomy

These night herons were formerly placed in the genus '' Nycticorax'', but today all major authorities recognize them as separate. In addition to the species listed below, the rufous or

nankeen night heron The nankeen night heron (''Nycticorax caledonicus'') is a heron that belongs to the genus '' Nycticorax'' and the family Ardeidae. Due to its distinctive reddish-brown colour, it is also commonly referred to as the rufous night heron. It is prim ...

has been placed in ''Gorsachius'', but today all major authorities place it in ''Nycticorax''. The white-backed night heron from sub-Saharan Africa and the white-eared night heron from China and Vietnam were previously placed in this genus, while they are now place in two

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genera.

References

* Martínez-Vilalta, A., & A. Motis (1992). Family Ardeidae (Herons). pp. 376–429 in: del Hoyo, J., A. Elliott, & J. Sargatal. eds (1992). ''

Handbook of the Birds of the World The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. ...

.'' Vol. 1. Ostrich to Ducks. Lynx Edicions, Barcelona. {{Taxonbar, from=Q135951 Bird genera Taxa named by Charles Lucien Bonaparte