Swainson's warbler (''Limnothlypis swainsonii'') is a small

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

New World warbler The New World warblers or wood-warblers are a group of small, often colorful, passerine birds that make up the family Parulidae and are restricted to the New World. The family contains 120 species. They are not closely related to Old World warb ...

. It is

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 ...

, the only member of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Limnothlypis''. Swainson's warbler was named after

William Swainson William Swainson Fellow of the Linnean Society, FLS, Fellow of the Royal Society, FRS (8 October 1789 – 6 December 1855), was an English ornithologist, Malacology, malacologist, Conchology, conchologist, entomologist and artist. Life Swains ...

, an

English English usually refers to: * English language * English people English may also refer to: Culture, language and peoples * ''English'', an adjective for something of, from, or related to England * ''English'', an Amish ter ...

ornithologist Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", is a branch of zoology dedicated to the study of birds. Several aspects of ornithology differ from related discip ...

Description

Swainson's warblers are a small and rather undistinguished songbird, though are fairly large for a New World warbler. Adults grow to in length and in weight. The wingspan averages . They are a plain olive-brown above and pale yellow-white below. They have a whitish eyebrow stripe that runs above their eye, and the top of their head is a rusty brown. Unlike most other New World warblers that are mostly dimorphic, there is no difference in appearance between a male or female Swainson's warbler.

Distribution and habitat

Swainson's warblers are uncommon, mostly found in flooded

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

lands and

canebrake A canebrake or canebreak is a thicket of any of a variety of ''Arundinaria'' grasses: '' A. gigantea'', '' A. tecta'' and '' A. appalachiana''. As a bamboo, these giant grasses grow in thickets up to tall. ''A. gigantea'' is generally found in s ...

s of the

south-eastern The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A ''compass rose'' is primarily composed of four cardinal directions—north, east, south, and west—each ...

United States. More rarely, they will also occur in

rhododendron ''Rhododendron'' (; : ''rhododendra'') is a very large genus of about 1,024 species of woody plants in the Ericaceae, heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan ...

thickets in the southern

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...

. They are a migratory species, with part of the population migrating southeastwards to the

Greater Antilles The Greater Antilles is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, and Jamaica, together with Navassa Island and the Cayman Islands. Seven island states share the region of the Greater Antille ...

(where it overwinters in the Blue Mountains of Jamaica for example) and the other southwestwards to the

Yucatán Peninsula The Yucatán Peninsula ( , ; ) is a large peninsula in southeast Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north and west of the peninsula from the C ...

region in winter.

Behavior

Breeding

This species begins breeding at about 10 months of age.Graves in Winker ''et al. 2000 Pairs form, and stake out and defend a territory for nesting. Nests are fairly large and bulky, constructed from moss, grass, and small leaves situated above ground in a tangle of tall reeds or vines. The female will lay between three and five eggs. The eggs are white and sometimes, but rarely, speckled with brown. Incubation is done by the female only and lasts for about 14 days, after which the eggs will hatch. The young leave the nest about 12 days later. It is not known how long pairs stay together, although once a pair-bond has been established they do not usually mate with other birds at least in the current

nesting season 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 lightwei ...

. These birds live to as old as eight years.

Taxonomy

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

are recognized. There appears to be some divergence between populations from

Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...

and others of the coastal plains. This does fit a pattern one would expect from

genetic drift Genetic drift, also known as random genetic drift, allelic drift or the Wright effect, is the change in the Allele frequency, frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene va ...

, but there seem to be no

geographical Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...

ecological Ecology () is the natural science of the relationships among living organisms and their environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely re ...

barriers restricting

gene flow In population genetics, gene flow (also known as migration and allele flow) is the transfer of genetic variation, genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent ...

. Even during the last ice age, when average temperatures,

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

and

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

s were lower, there seems to have been ample contiguous

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

. Clearly, some factor restricting gene flow is at work, but it is not presently known what it is. It is possible that the

subpopulation In statistics, a population is a set of similar items or events which is of interest for some question or experiment. A statistical population can be a group of existing objects (e.g. the set of all stars within the Milky Way galaxy) or a hypo ...

s conform to the different wintering areas.Winker ''et al.'' 2000 In some migrant birds, it is known that the initial direction of the migration is set by fairly simple

hereditary Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...

mechanisms. Offspring of pairs comprising birds of different subpopulations will, in such species, attempt to migrate into an intermediate direction. Such a course would lead a Swainson's warbler deep into the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

where there are no wintering or even stopover points, and the bird would almost certainly perish. More research such as analyzing

bird banding Bird ringing (UK) or bird banding (US) is the attachment of a small, individually numbered metal or plastic tag to the leg or wing of a wild bird to enable individual identification. This helps in keeping track of the movements of the bird an ...

data is needed to determine whether this mechanism applies in Swainson's warbler.

References

*Winker, K., Graves, G. R. & Braun, M. J. (2000) Genetic differentiation among populations of a migratory songbird: ''Limnothlypis swainsonii''. '' J. Avian Biol.'' 31(3): 319–328. PDF fulltext

External links

- VIREO * ttp://www.flmnh.ufl.edu/index.php/download_file/view/1330/724/ Sounds- Florida Museum of Natural History {{Taxonbar, from=Q783095

Swainson's warbler Swainson's warbler (''Limnothlypis swainsonii'') is a small species of New World warbler. It is monotypic, the only member of the genus ''Limnothlypis''. Swainson's warbler was named after William Swainson, an England, English ornithologist. Des ...

Native birds of the Southeastern United States