Lesser Goldfinch: the western finch that stays yellow all winter

The short answer

• A male Lesser Goldfinch has a black cap over the whole crown and yellow underparts in every month of the year. An American Goldfinch male has only a black forehead in summer and turns drab in winter.
• Undertail coverts settle the females and winter birds: yellow on Lesser, white on American.
• Green-backed birds occupy the West Coast and most of the interior West. Black-backed birds occupy Texas and the eastern edge of the range.
• Nyjer and sunflower hearts are its two top foods, the same pair as the American Goldfinch, so one feeder serves both.
• In dry country, water brings in more Lesser Goldfinches than any seed does.

If you are west of the Rockies or anywhere in Texas and a small yellow finch is on your nyjer feeder in January, start with this bird rather than with the American Goldfinch. Lesser Goldfinches keep their yellow all year, and that alone separates them from their commoner relative for six months of every twelve.

The three checks that settle it#

The undertail is the one to lean on, because it works on females, juveniles and winter birds, the three cases where everything else gets ambiguous. Get behind the bird, or watch it hang head-down on a mesh feeder, and the answer is right there.

Both sexes show a small white patch at the base of the primaries, which flashes on the folded wing and again in flight. Females are plain olive above and dull yellow below with no cap at all, and are the birds most often logged as "some kind of small greenish finch".

Voice is a genuine shortcut once you have it. The typical call is a thin, plaintive, descending tee-yee, quite unlike the bouncing four-note flight call of the American Goldfinch. Males also weave imitations of other species into their song, so a long rambling phrase with fragments of other birds in it, delivered from the top of a tree, is usually this species.

Green-backed and black-backed#

The two forms trip people up because field guides show both and yards usually hold one.

• Green-backed. The form of the West Coast, the Great Basin, the Rockies and most of the Southwest. Male has an olive-green back and black confined to the cap.
• Black-backed. The form of Texas and the eastern edge of the range. Male is glossy black across the whole of the upperparts, and looks like a different bird until you see the identical yellow underparts and white wing patch.

Where the two meet, intergrades with mottled or partly black backs are normal. Females of both forms are indistinguishable in the field.

Behavior at the feeder#

Lesser Goldfinches arrive as a flock, and the flock is the unit that matters. Ten to thirty birds settle at once, work the feeder for five to fifteen minutes, then lift off together when one bird spooks. They stage in a tree or on wires above the yard first, so if you see a line of small finches on a power line, check the feeder in the next few minutes.

At the feeder they behave like their larger relative: they cling in any orientation, feed head-down without hesitation, ignore perch length entirely, and cache nothing. In mixed flocks with American Goldfinches and House Finches they sit at the bottom of the pecking order and simply absorb the displacement, waiting a second and returning.

Two things separate them from an American Goldfinch in practice. They are lighter, at about 10 g, so a fine mesh sock that an American Goldfinch struggles to hold is comfortable for them. And they are far more strongly tied to water, because much of their range is dry. In the Southwest a dripper or a shallow moving-water bath will pull in more Lesser Goldfinches than any seed you can put out. The details are in bird baths and water.

Time of day skews early and late in summer heat, with a long midday absence once air temperatures pass roughly 95 °F. In spring and autumn they feed steadily all day.

What to put out#

1. Hearts Top
2. Nyjer Top
3. Black oil Yes

The practical version:

1. One nyjer feeder, filled shallow. A tube or fine mesh design as described in finch feeders, holding nyjer. In summer heat, fill a 24 oz tube with about 6 oz at a time. A full tube in a Phoenix or Sacramento July goes rancid before a flock can empty it, and rancid nyjer is the fastest way to lose the flock you spent a month attracting.
2. Sunflower hearts in a standard tube feeder. Rated top tier, cheaper per calorie eaten than nyjer, and taken by everything else in a western yard.
3. Black oil sunflower as the backup. Eaten readily, though a 10 g bird takes longer to open each shell than a House Finch does.
4. Water within 30 ft of the feeder. Shallow, moving, and cleaned as often as the feeder.

Leave garden seedheads standing. This is a specialist on the daisy family, and a row of spent sunflower, cosmos or coneflower heads in September does the work of a feeder for free. See native plants and cover.

Nothing is using the finch feeder#

• The seed is old. Same diagnosis as for every finch: pinch a nyjer seed, and if it is dusty and hollow rather than oily, replace the lot. Heat accelerates this, so the western failure window is shorter than the eastern one.
• The seed is wet or clumped at the base. Monsoon humidity and sprinkler overspray both do this. See moldy seed for what is actually growing in that plug.
• There is no water. In arid country this is not a refinement, it is the main attractant.
• House Finches hold the ports all day. Add a second feeder 15 ft or more away rather than trying to exclude them. Lesser Goldfinches will take the quieter station.
• The feeder sits in the open with no staging perch. They want a tree or wire within about 20 ft to gather on before dropping in.
• You are outside the range. East of central Texas and north of the Pacific Northwest, this bird is a rarity rather than a possibility. Check the map before spending a season on it.
• A sick flock has moved off. Any finch flock concentrates disease risk. Fluffed, lethargic birds with swollen eyes mean the feeder comes down. See bird diseases at feeders.

Across the year#

Lesser Goldfinches are largely resident, which makes their year quieter than the American Goldfinch's dramatic molt cycle. There is no plumage swap to confuse you and no continent-wide autumn shift.

Winter. Flocks concentrate at low elevations and in towns, and feeder numbers are usually at their highest. Birds that spent summer in foothill canyons move down into valleys and suburbs.

Spring. Flocks break up gradually from March. Males sing long mimicking phrases from exposed perches, often the highest twig of a garden tree.

Summer. Nesting is spread across a long window rather than concentrated, and pairs will still be feeding young in late summer. Feeder use dips during the hottest hours and water use climbs sharply.

Late summer and autumn. Numbers at feeders rise again as juveniles join the flocks and weedy ground sets seed. In the desert Southwest, expect a noticeable increase in the weeks after summer rains, when annual seed becomes abundant and flocks range widely between yards.

Frequently asked questions#

How do I tell a Lesser Goldfinch from an American Goldfinch?

Three checks. The cap: a male Lesser has black over the whole crown all year, a male American has a small black forehead patch only in breeding plumage. The underparts: a Lesser is yellow below in every season, an American goes drab buff from October to March. The undertail coverts: yellow on Lesser, white on American, in all plumages including females and juveniles. Size helps once you have both together, since a Lesser is noticeably smaller at about 10 g against 13 g.

What is the difference between green-backed and black-backed Lesser Goldfinches?

They are color forms of one species. Green-backed males, the form across the West Coast and most of the interior West, have an olive-green back with the black restricted to the cap. Black-backed males, found in Texas and along the eastern edge of the range, have glossy black over the entire upperparts. The two intergrade where they meet, so intermediate birds with mottled black and green backs are normal in that overlap. Females of both forms look the same: olive above, yellow below.

What do you feed Lesser Goldfinches?

Nyjer and sunflower hearts, both of which rate top tier for this species. Black oil sunflower is taken readily as well. A single nyjer tube or fine mesh feeder is enough to hold a flock, and because their food preferences match the American Goldfinch exactly, you do not need separate feeders where both occur. Skip corn, peanuts, mealworms and millet-heavy mixes: they will be picked over and dumped on the ground.

Do Lesser Goldfinches come to hummingbird feeders?

Sometimes. They will sip from a nectar port or, more often, from the drips and condensation around one, and they use fountains and drippers heavily. It is an occasional food rather than a staple, so treat it as a sign your yard is short of accessible water rather than as a feeding strategy. A shallow bath with moving water will serve them far better and keeps the nectar feeder free for the hummingbirds.

Are Lesser Goldfinches expanding their range?

Their range has been creeping north and east over recent decades, and they now turn up regularly in yards where nobody expected them, particularly in the Pacific Northwest and the western Great Plains. Feeders and irrigated suburban plantings almost certainly help. If you are on the northern or eastern edge of the mapped range, a small yellow finch with a black cap in midwinter is worth a careful second look rather than an automatic write-off.

Sources and further reading

1. Lesser Goldfinch Cornell Lab of Ornithology, All About Birds Plumage forms, range and diet
2. Guide to North American Birds National Audubon Society Distribution of the green-backed and black-backed forms
3. Feeding Birds Cornell Lab of Ornithology, Project FeederWatch Finch feeder and nyjer guidance