American Goldfinch Spinus tristis Linnaeus       Field Guide IDs: NG-452; G-320; PE-272; PW-pl 55; AE-pl 385; AW-pl 408; AM(III)-344 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F I: 10-12 DAYS ALTRICIAL TREE 1 foot - 30 feet (To 60 feet) F 4-6 (3-7) MONOG? F: 11-17 DAYS MF INSECTS GROUND GLEAN BREEDING: Weedy and cultivated fields, open decid and riparian woodland. Occ 2 broods. DISPLAYS: Male song-flight on level (rather than typical undulating) flight, rapidly flapping wings. NEST: In branch fork, often woven so tightly that nest holds water; of forbs, other pliable veg, lined with plant down. Caterpillar webbing and spider silk often used to bind outer rim. Male may collect some nest material and give to female. EGGS: Pale blue or bluish-white, unmarked. 0.6" (16 mm). DIET: Includes seeds of decid trees, forbs (esp composites), grass, floral buds, berries. Young fed regurgitant of milky seed pulp; few insects. CONSERVATION: Winters s to n Mexico (and along coast to Veracruz). Common cowbird host. Declined in n e as House Sparrows increased. NOTES: Commonly change mates between years; females show nest-site tenacity. Nests usu near water. Male feeds female on nest; female may call to male to be fed, begs when he appears with food. Females may sit on eggs 95% of the time! Hatching asynchronous, increasingly so as season progresses. Late nester except in CA and s w; older birds nest earlier than younger birds. Winter flocks up to 300 common, often with siskins, redpolls. STANFORD. NOTES: Fairly common migrant and winter resident in various habitats virtually throughout campus. Often forages in flocks (occasionally at feeders) during the nonbreeding season. ESSAYS: Bird Biology and the Arts; Site Tenacity; Mixed-Species Flocking; Incubation Time; Incubation: Heating Eggs; Brood Reduction; Cowbirds REFERENCES: Middleton, 1978, 1979; Skagen, 1987.