Spinus

Spinus is a genus of small to medium-sized passerine birds in the finch family Fringillidae. The genus includes several species commonly known as goldfinches and siskins, with the American goldfinch (Spinus tristis) and the pine siskin (Spinus pinus) among the best known members. Members of Spinus are typically seed-eaters with stout, conical bills.

Taxonomy and systematics: Spinus has undergone revisions in light of molecular studies. It is now widely treated as a distinct genus within Fringillidae, with several species formerly placed in Carduelis reassigned to Spinus by major authorities. Some taxonomic treatments continue to reflect older classifications, illustrating ongoing debate over finch relationships.

Description and behavior: Species in Spinus are generally small and active, measuring roughly 9–14 cm in length. Males often display brighter plumage with yellow or olive tones and clear wing bars, while females and juveniles are more subdued. They are social birds, forming flocks outside the breeding season and sometimes joining mixed-species groups. Diet consists mainly of seeds, with some buds and occasional insects during the breeding season.

Distribution and habitat: The majority of Spinus species occur in the Americas, with some representatives recognized in Eurasia depending on taxonomic treatment. They inhabit a variety of open and semi-open habitats, including woodlands, scrub, savannas, and agricultural areas, where they forage for seeds and insects.

Breeding and conservation: Nests are typically built in shrubs or low trees, with the female laying several pale eggs. Incubation and fledging timelines vary by species. Most Spinus species are currently listed as Least Concern by major conservation authorities, though local populations can decline due to habitat loss and changes in food availability.