By Tanya Dewey
Geographic Range
The breeding range reaches as far north as Saskatchewan and continues across the whole of North America, with the southern limits being North Carolina in the east and northern California in the west. The wintering range extends across the entire continental United States, extending well into Mexico along the Gulf coast. ()
Habitat
American goldfinches prefer weedy fields and flood plains in their breeding range. These habitats include early successional growth, cultivated lands, roadsides, orchards, and gardens. This habitat preference is maintained during the spring and fall migration. Winter habitats vary more than summer habitats, with finches moving near to human feeders (if available) in the northern part of their range. In the southern parts of their range, they tend to remain in habitats that closely approximate the weedy fields and flood plains of the north. ()
These animals are found in the following types of habitat:
temperate ; terrestrial .
Terrestrial Biomes:
savanna or grassland ; scrub forest .
Other:
suburban ; agricultural ; riparian .
Physical Description
American goldfinches are small finches with small conical bills. They are olive brown above, blending to olive yellow below. Males have bright yellow throats and jet black wing feathers. Females do not have a bright coloring. Their wing feathers are dull brownish-black. ()
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: sexes colored or patterned differently, male more colorful.
Reproduction
American goldfinches may lay up to 3 clutches each year.
Breeding begins in late June or July.
Pair formation occurs in winter. Experienced females will desert their mate in up to 15% of cases to have a second brood with another male. In those cases the first male takes over full responsibility for raising the young. ()
Breeding begins in late June or early July. The male watches attentively as the female builds the nest. The nest building takes her about six days. From 2 to 7 eggs are laid, often at night. Nesting success varies depending on the experience of the parents. In one study, experienced parents successfully raised 3.4 young per clutch and inexperienced parents raised 2.8 young per clutch. The female then incubates the eggs for 12 to 14 days before hatching. and the male feeds her. The female may leave with the male for short periods of a few minutes. ()
American goldfinches breed for the first time in the year after they hatch. ()
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous .
American goldfinch young hatch naked, with reddish bodies and eyes closed. They develop quickly, opening their eyes by day three and fully opening them by day seven. ()
Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female, female); pre-hatching/birth (provisioning: female, female, protecting: male, female, male, female); pre-weaning/fledging (provisioning: male, female, male, female, protecting: male, female, male, female).
Lifespan/Longevity
American goldfinches have been recorded living up to 11 years in the wild and in captivity.
Behavior
American goldfinches display the typical undulating flight of finches. They beat their wings a few times, causing them to ascend, followed by a brief descent on closed wings. This flight causes a flock to have a light, buoyant, dancing appearance. Flocks are formed often, since goldfinches are social at all times of the year. ()
American goldfinches are active during the day. They migrate between summer and winter ranges throughout most of their range. They are often seen in groups in shrubs and weeds as they forage for seeds. ()
Food Habits
American goldfinches consume many different types of seeds from annual plants. Analysis of the stomach contents of one goldfinch showed 50 different items, only 3 of which were insects. The others included a wide variety of "weed" seeds, such as seeds from grasses and trees (alder, birch, cedar, elm, etc.) Goldfinches are well adapted to hanging on seed heads, and they prefer this to feeding on the ground. Goldfinches drink by obtaining a mouthful of water and quickly tipping the head back to swallow. ()
Animal Foods:
insects.
Plant Foods:
seeds, grains, and nuts.
Predation
Although predation at the nest is a common cause of nest failure, American goldfinches are surprisingly non-aggressive towards predators. American goldfinches display little aggressive behavior, other than alarm calling. ()
Ecosystem Roles
American goldfinch nests are sometimes parasitized by brown-headed cowbirds, resulting in a loss of goldfinch eggs and young. However, cowbird young are not successfully fledged from American goldfinch nests. ()
American goldfinches are parasitized by feather mites (Acari) and louse flies (Hippoboscidae). In wild populations coccidial infections often result in death (Isospora). American goldfinches are an intermediate host for swimmer's itch (Schistosoma dermatitis). ()
- brown-headed cowbirds (Molothrus ater)
- louse flies (Hippoboscidae)
- feather mites (Acari)
- coccidia (Isospora)
- Schistosoma dermatitis
Economic Importance for Humans: Negative
There are no known negative effects of American goldfinches on humans. ()
Economic Importance for Humans: Positive
American goldfinches are enjoyed by birdwatchers at their feeders. They may also help to disperse seeds. ()
Ways that people benefit from these animals:
ecotourism .
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Migratory Bird Act: [link]:
Protected.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
State of Michigan List: [link]:
No special status.
Currently, American goldfinch populations are not decreasing. It is thought that their populations have increased since European settlement of North America. The clearing of forests for agriculture has vastly expanded the preferred habitat of American goldfinches. ()
Contributors
Tanya Dewey (author), Animal Diversity Web, University of Michigan Museum of Zoology.
Jennifer Roof (author), University of Michigan.