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Birdaday Field Notes

Species profile

House Finch: identification, look-alikes, feeders, nesting and eye disease

The House Finch is the red-headed finch that arrives at a sunflower feeder in a noisy group. Once a bird of the western US and Mexico, it now sings in most neighborhoods across the continent (Cornell). It is also the bird most affected by House Finch eye disease, so this profile ends with what the Cornell Lab and two state wildlife agencies tell feeder owners to do.

Quick facts

Fact House Finch
Scientific name Haemorhous mexicanus, family Fringillidae (Cornell)
Length 5.1–5.5 in (Cornell); 5–6 in (Audubon)
Weight 0.6–0.9 oz, 16–27 g (Cornell); 0.6–1 oz (Audubon)
Wingspan 7.9–9.8 in (Cornell); 8–10 in (Audubon)
Population About 40 million breeding birds (Cornell, Audubon); slight decline 1966–2019 (Breeding Bird Survey, via Cornell)
Status Low Concern (Cornell); Least Concern (IUCN, via Audubon)
Oldest known A female at least 11 years 7 months old, banded in New York in 1973 and recaptured there in 1985 (Cornell)

How to identify a House Finch

Cornell describes a small, bulky-billed finch, House Sparrow-sized but slimmer, with a long-looking, shallowly notched tail.

Male color ranges from yellow to bright red, depending on the pigments in the food a male eats while molting; females tend to prefer the reddest males (Cornell).

Adult male House Finch perched on the rim of a green seed feeder, holding a sunflower seed in its bill: red forehead, eyebrow, throat and breast, brownish cheek and brown streaked wings Female House Finch standing on gravel in side view: plain brown head with no face stripes, short thick bill, and blurry brown streaks on pale underparts
Left: adult male at a feeder in Brooklyn, New York (November 2020), with red on the forehead, eyebrow and throat and a brownish cheek (Cornell). Right: female in East Hartford, Connecticut (August 2023), with a plain face and blurry streaks (Cornell, FeederWatch). The male is a Featured picture and the female a Quality image on Wikimedia Commons; sex as given on each file page.
Photos: Rhododendrites / CC BY-SA 4.0, via Wikimedia Commons; Paul Danese / CC BY-SA 4.0, via Wikimedia Commons

House, Purple or Cassin's Finch?

Their ranges overlap, mainly because the House Finch is everywhere; in parts of the West all three occur together (FeederWatch). The Purple Finch breeds in northern North America and along the Pacific Coast and winters erratically across the central and southeastern US; Cassin's Finch lives in western mountain evergreen forests up to about 10,000 ft (Cornell).

Field mark House Finch Purple Finch Cassin's Finch
Male color Yellow to orange to red, rarely purple or rosy; red "headband" against a brown cap and cheek (FeederWatch) Deep reddish-purple over most of head, back and chest (FeederWatch); pinkish wash likened to raspberry juice (Cornell Bird Academy) Bright red crown contrasting with a pinkish face (FeederWatch); crown often peaks up (Cornell Bird Academy)
Male flanks Conspicuously streaked (FeederWatch) Belly and flanks without distinct streaks (Cornell Bird Academy) Finely streaked sides (FeederWatch)
Female face No strong pattern (FeederWatch) Bold white eyebrow, dark cheek, white stripe below the cheek (FeederWatch) Faint eyebrow and moustache; sometimes a pale eye ring (FeederWatch)
Female underparts Dull white, long thin smudgy streaks Bright white, short thick smudgy streaks Bright white, sharply defined streaks
Undertail coverts Broad dark streaks Usually unstreaked white, diagnostic if seen Well-defined dark streaks (all FeederWatch)
Bill and tail Short, stubby, curved top edge; slightly notched tail (FeederWatch) Short conical bill; short, deeply notched tail (FeederWatch) Heavy bill with a nearly straight top edge; short, deeply notched tail (FeederWatch)
Female House, Purple and Cassin's Finch comparedThree simplified brown-and-white female finches perched side by side, facing left. The House Finch has a plain brown face, long blurry breast streaks, a curved stubby bill and broad dark streaks under the tail. The Purple Finch has a bold white eyebrow, a dark cheek and a white stripe below it, short thick streaks and a plain white undertail. Cassin's Finch has a faint eyebrow, a pale eye ring, sharp thin streaks, a straight-edged bill and crisp streaks under the tail. Numbered markers point to each field mark. 1 2 3 4 5 6 7 8 9 House FinchPurple FinchCassin's Finch
  1. House face: no strong pattern; short, stubby bill with a curved top edge.
  2. House underparts: dull white with long, thin, smudgy streaks.
  3. House undertail: broad dark streaks.
  4. Purple face: bold white eyebrow, dark cheek patch, white stripe along the bottom of the cheek.
  5. Purple underparts: bright white with short, thick, smudgy streaks.
  6. Purple undertail: usually plain white; diagnostic if you can see it.
  7. Cassin's face: faint eyebrow and moustache stripe, sometimes a pale eye ring; heavy bill with a nearly straight top edge.
  8. Cassin's underparts: bright white with sharply defined streaks.
  9. Cassin's undertail: well-defined dark streaks.
Drawn for Birdaday Field Notes as generic finch shapes, following Project FeederWatch's Tricky Bird ID page on these three finches and the Cornell Lab's All About Birds and Bird Academy pages, cited below. Females shown; not to scale; colors simplified.

Song and calls

Range: from the West to every neighborhood

When What happened
Before 1870 Introduced to Oahu; abundant on all major Hawaiian Islands by 1901 (Cornell)
1940 A small number released on Long Island, New York (Cornell, Audubon)
About 50 years later Spread across most of the eastern US and southern Canada (Cornell); met western birds on the Great Plains (Audubon)

Accounts of 1940 differ: Cornell says the birds were freed after attempts to sell them as "Hollywood finches" failed; Audubon says pet shop owners released illegally held birds to avoid prosecution. Western birds are mostly permanent residents; some eastern birds migrate south in fall (Audubon).

Food and feeders

House Finches eat almost only seeds, buds and fruit, and feed their nestlings only plant foods, which is rare among birds (Cornell).

Topic What the sources say
Best seed Black-oil sunflower over striped sunflower; also millet and milo (Cornell)
Where it feeds At feeders, on the ground, on weed stalks and in trees (Cornell); also visits hummingbird feeders for sugar water (Audubon)
Flock size Flocks of 50 or more may come to feeders (Cornell)

See what to feed backyard birds and bird feeder types.

Nesting

House Finches nest in trees, cactus and rock ledges and on buildings: vents, ledges, street lamps, ivy and hanging planters (Cornell). The cup of fine stems, leaves, rootlets, string and feathers is built mostly by the female (Audubon).

Stage Cornell Lab Audubon
Nest height — Usually about 12–15 ft
Clutch 2–6 eggs Usually 4–5, occasionally 2–6
Eggs Light blue to whitish, finely speckled Pale blue, dotted black and lavender
Incubation 13–14 days About 13–14 days, by the female
Nestling period 12–19 days Leave the nest about 12–15 days after hatching
Broods 1–6 Up to 3 a year, possibly more

House Finch eye disease

Mycoplasmal conjunctivitis is a respiratory infection, seen as eye inflammation, caused by a strain of Mycoplasma gallisepticum, a bacterium common in domestic chickens and turkeys (FeederWatch).

Signs: red, swollen, runny or crusty eyes. In severe cases the eyes swell shut and the bird is essentially blind; it may stay on the ground under feeders (FeederWatch). Birds that die usually die of starvation, exposure or predation rather than the infection itself; some recover (FeederWatch).

Who gets it: mainly House Finches. Cases are also confirmed in American Goldfinch, Purple Finch, Evening Grosbeak and Pine Grosbeak (FeederWatch). It poses no known threat to people (FeederWatch, Wisconsin DNR).

How it spreads: through eye discharge where birds gather. Tube feeders carry the highest risk because discharge can stay on the feeding ports (Michigan DNR, Wisconsin DNR). The bacterium survives only briefly outside a bird (Michigan DNR, Wisconsin DNR). A 2015 Virginia Tech study found that the finches that visited feeders most were the most likely to catch and to spread it (FeederWatch).

House Finch introduction and eye disease timeline, 1940 to 2020A timeline from 1940 to 2020 with eight numbered events: the 1940 Long Island release; eastern and western birds meeting on the Great Plains about 50 years later; the disease first noticed in winter 1993 to 1994; nearly all states east of the Rockies affected within seven years; the disease crossing the Rockies from 2006; the stand-alone disease survey ending in 2008; Cornell renewing data collection in 2013; and a 2015 Virginia Tech feeder study. Shading marks the years since the disease was first noticed. Hollow dots are approximate dates. 19401960198020002020 1 2 3 4 5 6 7 8
  • Years since the disease was first noticed
  • Approximate date
  1. 1940: House Finches released on Long Island, New York (Cornell, Audubon).
  2. About 50 years later: eastern birds meet western birds on the Great Plains (Audubon).
  3. Winter 1993–94: eye disease first noticed at feeders in Virginia, Maryland and the Washington, D.C., area (FeederWatch, Michigan DNR).
  4. Within seven years: diagnosed across nearly all states east of the Rocky Mountains (Michigan DNR).
  5. Since 2006: the disease has crossed the Rockies into western states (FeederWatch).
  6. 2008: Cornell's stand-alone House Finch Disease Survey, begun in 1994, ends; monitoring continues in Project FeederWatch (FeederWatch).
  7. 2013: Cornell renews data collection with a modified FeederWatch protocol (FeederWatch).
  8. 2015: Virginia Tech study links frequent feeder use to catching and spreading the disease (FeederWatch).
Timeline drawn for Birdaday Field Notes from Project FeederWatch, the Michigan DNR and Audubon, cited below. Hollow dots (2, 4) place approximate phrases; positions are to scale by year.

Effect on populations: after the epidemic, populations fell sharply within 2–3 years and then stabilized at about 40% of their earlier abundance (Michigan DNR). FeederWatch estimates that 5–10% of the eastern House Finch population now has the disease, and its spread has leveled off.

If you see a finch with swollen eyes

Every source starts the same way: take feeders down and clean them with a 10% bleach solution, 1 part bleach to 9 parts water (FeederWatch, Michigan DNR, Wisconsin DNR). How long to wait differs:

Source What to do and for how long
Project FeederWatch Take feeders down, clean with 1:9 bleach, let them dry completely, rehang; rake up old seed and droppings underneath. A 2015 FeederWatch post adds that you may leave feeders down for a few days so sick birds disperse
Wisconsin DNR After finding a sick or dead bird, disinfect the feeder or bird bath and wait at least a week before putting it back; move it if possible
Michigan DNR Stop feeding, clean feeders with 10% bleach and keep them down for at least 2 weeks; avoid tube feeders

Routinely: clean feeders even when birds look healthy, space them widely and rake up hulls and moldy seed (FeederWatch). Schedule by feeder type: how to clean a bird feeder.

Don't treat the birds. Only licensed professionals may handle most wild birds, and medication should never go in seed or bird baths (FeederWatch). FeederWatch and the Michigan DNR both warn that treating wild birds can help the disease spread and that antibiotics can lead to new or resistant strains.

For your Bird-a-Day streak

A feeder regular, the House Finch makes an easy reserve bird, and its song counts by ear (challenge guide). A Purple Finch is a separate day: check brown finches for a white eyebrow. Plan with the species planner.

House Finch checklist

Sources