The Gnatcatchers are a family of small
passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by t ...
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
s called Polioptilidae. The 21 species occur in
North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography.
Etymology
T ...
and
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
(except for the far south and the high
Andean regions). Most species of this mainly
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
and
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...
group are resident, but the
blue-grey gnatcatcher of the United States and southern
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
migrates south in winter. They are close relatives of the
wren
Wrens are a family of brown passerine birds in the predominantly New World family Troglodytidae. The family includes 88 species divided into 19 genera. Only the Eurasian wren occurs in the Old World, where, in Anglophone regions, it is commonly ...
s.
[Atwood, J. & Lerman, S. (2006) Family Polioptilidae (Gnatcatchers). pp. 350–377 in: del Hoyo, J., A. Elliott, and D. Christie. eds (2006). '']Handbook of 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. Th ...
'' Vol. 11. Old World Flycatchers to Old World Warblers. Lynx Edicions, Barcelona.
Description
These dainty birds are intermediate between
Old World warbler
Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the ci ...
s and
wren
Wrens are a family of brown passerine birds in the predominantly New World family Troglodytidae. The family includes 88 species divided into 19 genera. Only the Eurasian wren occurs in the Old World, where, in Anglophone regions, it is commonly ...
s in their structure and habits, moving restlessly through foliage seeking insects. The gnatcatchers are mainly soft bluish grey in colour, and have the typical insectivore's long sharp bill. Many species have distinctive black head patterns (especially males) and long, regularly cocked, black-and-white tails. The skulking gnatwrens are browner, more thickset, and with proportionally shorter tails and longer bills.
Distribution and habitat
They are distributed from
North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography.
Etymology
T ...
to
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
, with the exception of the far south and high
Andean regions. Gnatwrens typically occur in the undergrowth of dense, often humid, forest, while gnatcatchers, depending on the species involved, occur in anything from dry scrubby habitats (e.g. the California gnatcatcher) to the
canopy of humid
Amazonian forest (e.g. the Guianan gnatcatcher). The North American species nest in bushes or trees, but the breeding behavior of several of the
Neotropical
The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone.
Definition
In bioge ...
species is essentially unknown.
Taxonomy and systematics
A species
new to science, the
critically endangered Iquitos gnatcatcher ''
Polioptila clementsi
The Iquitos gnatcatcher (''Polioptila clementsi'') is a bird in the family Polioptilidae. It was first described in 2005. It is known only from the Allpahuayo-Mishana National Reserve, west of Iquitos, Peru.
Taxonomy and systematics
The Iq ...
'', was first described in 2005.
[Whitney, B. & Alonso, A. (2005) A new species of gnatcatcher from the white-sand forests in northern Amazonian Peru with revision of the ''Polioptila guianensis'' complex. ''Wilson Bull.'' 117(2): 113-210.] This species is a member of the Guianan gnatcatcher ''
Polioptila guianensis
The Guianan gnatcatcher (''Polioptila guianensis'') is a species of bird in the family Polioptilidae. It is found in Brazil, French Guiana, Guyana, Suriname, and Venezuela.
Taxonomy and systematics
The Guianan gnatcatcher is monotypic. Two f ...
'' complex, which recently has been proposed split into three species (four with the Iquitos gnatcatcher), but not all authorities have accepted this (e.g.
SACC). Furthermore, other groups should possibly be split, notably the tropical gnatcatcher ''
Polioptila plumbea
The tropical gnatcatcher (''Polioptila plumbea'') is a small active insectivorous songbird, which is a resident species throughout a large part of the Neotropics. There are large geographical variations in its voice and plumage, resulting in some ...
'' and masked gnatcatcher ''
Polioptila dumicola
The masked gnatcatcher (''Polioptila dumicola'') is a small songbird in the family Polioptilidae. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.
Taxonomy and systematics
The masked gnatcatcher has three recognized subspec ...
'' complexes, but at present scientific papers on these matters are lacking.
The family contains 21 species divided into 3 genera:
*''
Ramphocaenus
''Ramphocaenus'' is a genus of passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are di ...
'' (2 species) – gnatwrens
*''
Microbates'' (2 species) – gnatwrens
*''
Polioptila
''Polioptila'' is a genus of small insectivorous birds in the family Polioptilidae. They are found in North and South America.
The genus ''Polioptila'' was introduced by the English zoologist Philip Sclater in 1855. Although he listed several m ...
'' (17 species) – gnatcatchers
References
External links
Gnatcatcher videoson the Internet Bird Collection
{{Taxonbar, from=Q752549
*
*
Taxa named by Spencer Fullerton Baird