Lesser goldfinches (Spinus psaltria) are very small songbirds of the Americas. They are common at feeders in the Southwest United States and will come almost anywhere with thistle sock feeders.
Male Lesser goldfinches are easily recognized by their bright yellow underparts and big white patches in the tail (outer rectrices) and on the wings (the base of the primaries). They range from having solid black from the back to the upper head including the ear-coverts to having these regions medium green; each of the back, crown and ear regions varies in darkness rather independently though; as a rule, the ears are not darker than the rest. Females' and immatures' upperparts are more or less grayish olive-green; their underparts are yellowish, buffier in immatures. They have only a narrow strip of white on the wings (with other white markings in some forms) and little or no white on the tail. They are best distinguished from other members of the genus by the combination of small size, upperparts without white or yellow, and dark gray bill. In all plumages, this bird can easily be taken for a New World warbler if the typical finch bill is not seen well.
Lesser goldfinches range from the southwestern United States (near the coast, as far north as extreme southwestern Washington) to Venezuela and Peru. It migrates from the colder parts of its U.S. range. They live in almost any habitat with trees or shrubs except for dense forest and are common in farmlands, parks, gardens, suburban and urban areas and often come near houses.
Lesser goldfinches often spend time in flocks or at least loose associations. They are very quick diurnal birds. Flocks fly and forage together not staying at one place for too long and often visit feeders. Lesser goldfinches have an undulating flight in which they frequently give a harsh 'chig chig chig' call. Another distinctive call is a very high-pitched, drawn-out whistle, often rising from one level pitch to another (teeeyeee) or falling (teeeyooo). The song is a prolonged warble or twitter, often incorporating imitations of other species.
Lesser goldfinches are herbivores (granivores) and carnivores (insectivores). They mainly eat tree buds, weed seeds, coffeeberry, elderberry, and madrone fruits, and will also eat insects such as plant lice.
Lesser goldfinches are monogamous and form pairs. They breed in summer in the temperate parts of their range; in the tropics, they apparently breed all-year round, perhaps less often in September and October. The female lays 3-4 bluish-white eggs in a cup nest made of fine plant materials such as lichens, rootlets, and strips of bark. The nest is typically placed in a bush or at low or middle levels in a tree. The female incubates the eggs for 12-13 days and the male brings her food during this period. The chicks hatch blind and naked and remain in the nest for about 12-14 days.
Lesser goldfinches don't face any major threats at present.
According to the All About Birds resource, the total breeding population size of the Lesser goldfinch is 15 million individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
Lesser goldfinches help spread the seeds throughout their range allowing plants to grow in new areas and provide food and habitats for other organisms.