Cowbirds are

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s belonging to 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 ...

''Molothrus'' in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Icteridae. They are of

New World The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: ...

origin, but some species not native to North America are invasive there, and are obligate

brood parasite Brood may refer to: Nature * Brood, a collective term for offspring * Brooding, the incubation of bird eggs by their parents * Bee brood, the young of a beehive * Individual broods of North American periodical cicadas: ** Brood X, the largest ...

s, laying their eggs in the nests of other species. The genus was introduced by English naturalist

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 ...

in 1832 with the brown-headed cowbird (''Molothrus ater'') as the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. The genus name combines the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

, meaning "struggle" or "battle", with , meaning "to sire" or "to impregnate". The English name "cowbird", first recorded in 1839, refers to this species often being seen near cattle.

Species

The genus contains six species: One

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species, '' Molothrus resinosus'', is known from

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

remains recovered from the Talara Tar Seeps of northwestern

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, and likely went extinct during the

late Quaternary The Holocene () is the current geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Qu ...

. It may have been a close associate of Pleistocene megafauna communities, and may have gone extinct following their collapse in populations. The convex-billed cowbird (''Pandanaris convexa'') is another extinct species that likely co-evolved with the megafauna, though it is placed in its own genus. The nonparasitic baywings were formerly placed in this genus; they are now classified as ''Agelaioides''.

Behavior

Cowbirds eat mostly insects and seeds. Some species follow

ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...

s to catch insects stirred up by the larger animals' grazing. Cowbirds reproduce by laying their eggs in other birds' nests. Female cowbirds observe a potential host bird laying its eggs, and when the nest is left momentarily unattended, the cowbird lays its own egg in it. The female cowbird may continue to observe this nest after laying eggs. Some bird species have evolved the ability to detect such parasitic eggs, and may reject them by pushing them out of their nests, but female cowbirds has been observed to attack and destroy the remaining eggs of such birds in retaliation, as suggested by the Mafia hypothesis.

References

External links

Audubon Society: Cowbirds and Conservation
{{Authority control Brood parasites Birds of North America Bird genera Taxa named by William Swainson

Species

Behavior

References

Further reading

External links