Taxonomic name: Carpodacus mexicanus (Statius Muller, 1776)
Common names: house finch (English), pinzon mexicano (Spanish)
Organism type: bird
Carpodacus mexicanus (house finch) is native to the western United States and Mexico. In 1940, wild birds illegally sold as "Hollywood Finches" in New York were released by dealers anxious to avoid prosecution, and populations now exist throughout eastern North America. In many areas, house finches are not considered a nuisance and are appreciated for their musical song and bright colours. However, they are highly adaptable to urban and suburban environments as they peck and feed on practically all deciduous fruits, berries, grains and seed. Consequently, large populations have become a nuisance, even in their native range, where they have caused economic losses in agricultural areas.
Carpodacus mexicanus (house finches) are about the same size as house sparrows. Males are brownish with a bright red breast, forehead, rump and stripe over the eye. They also have narrow dark stripes on the flanks and belly. Females are sparrow-like, with a plain head, streaked underparts and no eye stripe. House finches have a warbling song, frequently ending in harsh, nasal notes. Their chirp is similar to that of a house sparrow (Clark, J., Hygnstrom, S. 1994).
agricultural areas, desert, natural forests, range/grasslands, riparian zones, urban areas
In the eastern United States, Carpodacus mexicanus (house finches) are highly adaptable to urban and suburban environments. They are especially invasive in agricultural areas. House finches are also found in open desert and desert grassland, chaparral, oak savannah, riparian areas and open coniferous forests in the western United States (Pappas, 2002). House finches nest on ledges, on branches of trees, shrubs and cactus and in holes in trees or wall (InfoNatura, 2004).
Carpodacus mexicanus (house finches) peck and feed on practically all deciduous fruits, berries, grains, vegetable seed and flower seed. Damage involves feeding on ripening fruit, such as apples, apricots, avocados, blackberries, cherries, figs, grapes, nectarines, peaches, pears, plums, prunes, raspberries and strawberries. They also detach the bracts of fruit buds and eat the buds; at blossom time they knock off petals and eat the embryonic fruits. Damage occurs to ripening fruit during three periods: early season (damage by nesting adults), mid to late season (damage by young and adult birds resident in the locality), and winter (damage to late ripening fruit by flocks of birds gathering in their winter habitats) (Clark, J., Hygnstrom, S. 1994).
House finches use nests of other species (e.g., grosbeak, cliff swallow). They are however not considered a competitive threat to native cavity nesting birds in eastern North America (InfoNatura, 2004).
Native range: Carpodacus mexicanus (house finches) are native to the western United States and Mexico.
Known introduced range: Carpodacus mexicanus (house finches) now occur in the western and eastern United States all year, but are absent from the Great Plains area. Introduced populations in eastern North America occur throughout the southeast in winter and in the northern areas during the breeding season (Pappas, 2002).
Introduction pathways to new locations
Other: In 1940, wild house finches (Carpodacus mexicanus) illegally sold in New York as "Hollywood Finches" were released by dealers anxious to avoid prosecution (Pappas, 2002).
Local dispersal methods
Agriculture (local): Clark and Hygnstrom (1994) indicates that the house finch population and range expansion is aided by the presence of crop fields.
Physical: Clark and Hygnstrom (2005) describe several prevention and control methods. Exclusion involves installing plastic netting to protect crops. Habitat modification can deter house finches from feeding on crops and can be done by removing large brush piles, stacks of irrigation pipe, and piles of boxes to eliminate nesting and resting areas. Other methods of controlling the house finch population include frightening the birds with loud noises or alarms. Trapping devices may also be useful. Some repellents may be used, but they are not considered very effective. Shooting will somewhat reduce the number of birds present, but is a costly and rather futile method of crop protection.
Seeds, including those from thistle, dandelion, sunflower and mistletoe, as well as buds, are consumed. In addition, fruits such as cherries and mulberries are favoured. The house finch eats, almost exclusively, plant materials .
The nest is made of grasses, hair or any available fibres and is fashioned as a shallow cup. A clutch consists of three to six bluish or greenish-white eggs that are black-spotted near the large end. Each egg weighs approximately 2.4g.
Pair formation begins in the winter, culminating in pairbonds established just before the breeding season begins. Females are most likely to choose a mate that has the most brightly coloured plumage, rather than a dominant male. In the northeast of the USA, house finches may breed twice during the breeding season, which starts in the earliest part of spring. The female incubates her eggs for 12-14 days and the young fledge 11-19 days after hatching (Pappas, 2002).
Reviewed by: Kevin P. B. Oh. Graduate Student. Dr. Badyaev's Lab Department of Ecology & Evolutionary Biology, University of Arizona Tucson, USA.
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Wednesday, 24 January 2007