House Finch: a western bird that took over the East, and the disease it brought to feeders

The short answer

• House Finches were a western and Mexican bird until caged birds released on Long Island in 1940 founded an eastern population that spread across the continent.
• Male color comes from carotenoid pigments in what the bird eats while it molts, which is why males range from pale yellow through orange to deep red.
• Against a Purple Finch, look for a brown cap behind the red, heavy brown streaking on the flanks, and a squared tail.
• House finch eye disease is caused by a bacterium spread at feeders. Swollen, crusty eyes mean take the feeder down, clean it, and leave it down for a week or two.
• Safflower does not exclude House Finches. They eat it readily, which matters if you chose it to reduce crowding.

Until the middle of the twentieth century, a House Finch in New York was a bird that should not have been there. The species was native to the West, the Southwest and Mexico, and everything east of the Great Plains descends from one small release event.

How it got here#

House Finches were sold in the eastern pet trade as Hollywood Finches. That trade was illegal under federal migratory bird law, and in 1940 dealers on Long Island facing enforcement released their stock. Those birds bred, held on, and spread.

The expansion accelerated through the 1960s and 1970s, and by the 1990s the descendants of those released birds had met the native western population spreading east across the Great Plains. The two now form one continuous continent-wide distribution. East of the Rockies, the commonest bird on your feeder arrived within living memory.

Why the males are different colors#

Male House Finches are not reliably red. They run from deep crimson through orange to pale yellow, and all three can be at one feeder on one morning.

The pigments responsible are carotenoids, and birds cannot manufacture them. They have to be eaten, from fruits, buds and seeds, and they are laid down as the feathers grow. A male that molts with plenty of carotenoid-rich food grows red feathers. A male that molts on a poorer diet grows orange or yellow ones and is stuck with them until the next annual molt. Females attend to this: redder males tend to be preferred as mates.

House Finch, Purple Finch, Cassin's Finch#

The plain-faced female is the single most useful mark. If a streaky brown finch has a face with no pattern at all, it is a House Finch. If it has a strong white eyebrow and a dark jaw stripe, it is not.

Flock behavior at the feeder#

House Finches are sitters. Where a chickadee grabs one seed and leaves, a House Finch lands on a port and stays, husking seed after seed for minutes at a time. Multiply that by a flock of a dozen and one tube can be occupied most of the daylight hours, which is the mechanism behind almost every "they took over my feeder" complaint.

• Flock size: six to thirty is normal outside the breeding season, and they arrive together after staging on a wire or a bare branch.
• Approach: open and unbothered. They will use a feeder in the middle of a lawn that a cardinal will not touch, though cover within about 20 ft keeps them there longer.
• Dominance: they displace goldfinches and siskins routinely and give way to jays, grackles and cardinals.
• Time of day: all day, with the heaviest use in the last two hours before dusk.
• Caching: none. What they take, they eat on the spot.
• Nesting: ledges, hanging planters, wreaths on a front door, vents. A wreath nest runs about a month from first stick to fledged young, so leave it and use the back door. See feeding during nesting season.

Food and feeder choices#

Skip for this species: Peanuts (in shell), Mealworms.

They are generalists among small seed eaters, which is exactly why they are hard to manage. Note what the data does not say: safflower is eaten readily by this species. Safflower is a genuine tool against grackles and squirrels, but choosing it to reduce House Finch numbers will not work.

• Top-tier favorite for: Northern Cardinal
• Eaten readily by: Black-capped Chickadee, Tufted Titmouse, White-breasted Nuthatch, House Finch, Purple Finch, Mourning Dove, Rose-breasted Grosbeak
• Taken occasionally by: Blue Jay, Red-breasted Nuthatch, Downy Woodpecker, Hairy Woodpecker, Red-bellied Woodpecker, American Goldfinch, Lesser Goldfinch, Dark-eyed Junco, White-throated Sparrow, Eastern Towhee, Evening Grosbeak, Steller's Jay, California Scrub-Jay

A workable arrangement in a yard with heavy House Finch traffic:

1. Split the station. Two or three feeders at least 15 ft apart beat one big one. A flock holds a single feeder easily and a spread-out station poorly.
2. Give the smaller finches a head-down feeder. Ports below the perches, as covered in finch feeders, tilts access toward American Goldfinches.
3. Use black oil sunflower or hearts as the main seed in a tube or hopper. Both rate top tier, and there is no cheaper way to feed this bird well.
4. Skip mixes with a lot of filler. House Finches sort aggressively and dump what they do not want, which is the origin of most of the mess under a feeder.

For the wider question of what seed does and does not deter, see bird feeding myths.

Eye disease, and why hygiene is not optional here#

House finch eye disease is a bacterial conjunctivitis that appeared in eastern House Finches in the mid 1990s and spread rapidly through the population. An infected bird has red, swollen, watery or crusted eyes, often on one side first. Many become effectively blind. They rarely die of the infection itself: they die of starvation, cold or a cat, because they cannot see.

The transmission route matters to you directly. Birds pick it up from surfaces other birds have pressed their faces against, and a tube feeder port is exactly that surface.

Salmonellosis hits finch flocks in some winters and the response is the same. Follow your state wildlife agency if it asks people to stop feeding during an outbreak.

When they are not there#

They are missing far less often than people think, so start with the possibility that they are present under another name.

• You are calling them sparrows. Streaky brown birds at a feeder are usually female House Finches. Check the face for pattern and the bill for a curved upper edge, unlike a House Sparrow.
• A local die-off. After an eye disease or salmonellosis outbreak, numbers can stay low for months. Nothing to fix except hygiene.
• Nesting season. Late April through July, flocks break up and the feeder looks empty even though the birds are 40 ft away on a ledge.
• A hawk is working the yard. An open feeder suits House Finches and the accipiters that hunt them. The flock moves to a neighbor's yard for a week.
• Nothing but nyjer on offer. They eat it, but a yard with only a nyjer feeder gets a fraction of the traffic that one with sunflower gets.

Through the year#

Winter. The largest flocks and the heaviest feeder use. A station can be occupied dawn to dusk, and disease risk peaks with it, so the cleaning interval matters more than in any other season.

Spring. Singing starts early, often February, a long warbling phrase ending in a rising slur. Flocks break up into pairs and feeder counts fall.

Summer. Nesting near buildings, often two or three broods. Adults keep using feeders throughout, and by July they bring streaky juveniles that beg at the ports.

Autumn. The molt, and the weeks when this year's male color is set. Flocks re-form, juveniles join them, and numbers climb steadily from September into the winter peak.

Frequently asked questions#

Why are some House Finches orange or yellow instead of red?

The red comes from carotenoid pigments the bird takes in from fruits, buds and seeds while it is growing new feathers. A male that molts with good access to carotenoid-rich food grows deep red feathers. A male that does not comes out orange or pale yellow, and he keeps that color until the next molt. It is a record of one bird's diet during a few weeks of one autumn, not a subspecies, an age class or a different bird.

How do I tell a House Finch from a Purple Finch?

On males, look behind the red. A House Finch has a brown cap and brown nape behind the red forehead and eyebrow, with heavy brown streaks down the flanks and a squared or shallowly notched tail. A Purple Finch looks dipped in raspberry over the head, back and breast, has clean unstreaked flanks and a deeply notched tail. Females are easier than they look: a female Purple Finch has a bold white eyebrow and a dark cheek and jaw stripe, and a female House Finch has a plain, patternless brown face.

What is house finch eye disease?

It is conjunctivitis caused by a bacterium, first noticed in eastern House Finches in the mid 1990s and now widespread. Affected birds have red, swollen, watery or crusted eyes. Many go effectively blind, and they die of starvation, exposure or predation rather than of the infection itself. It spreads where birds press their faces against shared surfaces, which describes a tube feeder port exactly. Other finches can catch it too.

What should I do if I see a House Finch with swollen eyes?

Take every feeder down. Empty them, wash in hot soapy water, soak for ten minutes in one part household bleach to nine parts water, rinse and dry completely. Rake up and bin the seed and hulls underneath. Leave the feeders down for one to two weeks so the flock disperses, then start again with clean feeders spaced further apart. Report the sighting to Project FeederWatch if you take part. See bird diseases at feeders for the full protocol.

How do I stop House Finches taking over my feeders?

Do not expect a seed to do it: they eat safflower, nyjer, sunflower and hearts, so switching food changes little. What works is geometry. Run two or three smaller feeders at least 15 ft apart instead of one large one, so a flock cannot hold everything at once, and give the small birds a feeder with the ports below the perches, which House Finches use far less readily than goldfinches do.

Sources and further reading

1. House Finch Cornell Lab of Ornithology, All About Birds Introduction history, plumage variation and range
2. Sick Birds and Bird Diseases Cornell Lab of Ornithology, Project FeederWatch House finch eye disease symptoms and feeder response
3. Bird Feeder Maintenance and Cleaning Cornell Lab of Ornithology, Project FeederWatch Cleaning method and bleach dilution
4. National Wildlife Health Center United States Geological Survey Wildlife disease reporting and outbreak guidance