The variable seedeater (Sporophila corvina ) is a passerine bird which breeds from southern Mexico through Central America to the Chocó of northwestern South America. The taxonomy is confusing, and it was formerly considered a subspecies of Sporophila americana (see Taxonomy ). Even within the variable seedeater as presently defined, there are great variations in plumage.
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Flocking birds are those that tend to gather to forage or travel collectively. Avian flocks are typically associated with migration. Flocking also ...
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Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
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starts withThe variable seedeater is a small, robust bird with a black conical bill. It is 10.5 cm (4.1 in) long and weighs 11 g (0.39 oz). There are four subspecies, which differ primarily in the plumage of the male:
Previously, additional subspecies have been recognized for the various hybrid populations found where the above-mentioned subspecies meet (see Taxonomy ).
Females are olive-brown above, paler below, and have white wing linings like the male. The racial differences in the female plumages are minor, with S. c. hoffmannii, S. c. hicksii and S. c. ophthalmica generally being paler and less brown than S. c. corvina, and often with a faint yellow tinge below. Juveniles are like the adult female of their subspecies. Males may not acquire the full adult plumage in their first year, and may breed whilst still showing some immature features in their appearance.
A hypermelanic male was reported from Reserva Buenaventura in El Oro Province, Ecuador, in 2005. The bird had increased phaeomelanin; its white areas — except those of the wings — were bright tawny chestnut. A similar bird was collected along the "Pipeline Road" near Gamboa, Panama, in 1963. Such individuals seem to provide a glimpse at the circumstances of speciation: in the genera Sporophila and Oryzoborus, several species exist which differ externally only by one having white areas, the other being hypermelanic just as the two variable seedeaters mentioned here. Of course, there must be some factor maintaining reproductive isolation, but the plumage differences between such seedeater species pairs probably had their origin in such a mutation becoming fixed in a founder population due to genetic drift.
This seedeater is a common to abundant bird in lowlands and foothills up to 1,500 m (4,900 ft) altitude in semi-open areas such as forest edges, roadsides, low scrub and gardens. It also flocks with other species of seedeaters in pasture, weedy fields and other grassland.
This species feeds mainly on grass seeds but also takes other seeds, berries and some insects.
The flimsy cup nest, built by the female, is made of coarse plant material and lined with a few finer fibres. It is placed in a tree 0.4 to 6 m (1.3 to 19.7 ft) up, occasionally higher, in the fork of a twig. The clutch is two or three brown-speckled pale grey eggs, which are incubated by the female alone for 12–14 days to hatching.
The variable seedeater has a harsh chur call. The male's song consists of a mixture of warbles, whistles, and twitters, and is more elaborate on the Pacific slope.