Violet-green Swallow Tachycineta thalassina Swainson       Field Guide IDs: NG-322; G-220; PW-pl 43; AW-pl 357; AM(II)-300 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F I: 13-14 DAYS ALTRICIAL 5 feet + F -M(?) 4-6 MONOG F: 16-24 DAYS F-M BREEDING: Conif or decid open forest or woodland, often at higher altitudes. 1 brood. DISPLAYS: Predawn song-flights may be part of courtship. NEST: In tree hole or other cavity; of grass and weed stems, lined with feathers. EGGS: White, unmarked. 0.8" (19 mm). DIET: Insects only rarely taken on ground. CONSERVATION: Winters s to Honduras. Forestry practice of removing standing dead trees has greatly reduced availability of natural nest sites; will use nest boxes. NOTES: Occ nest in loose colonies of up to 20 pairs. Defends area around nest hole from other cavity-nesting species of swallows. Several pairs have been documented helping Western Bluebirds to rear nestlings and subsequently breeding in the nest box after the bluebirds fledge. Like other swallows, often perches in long rows on wire. House Sparrows compete for nest cavities. Flocks occ with Tree Swallows. STANFORD. NOTES: Uncommon to fairly common migrant and summer resident. Large flocks of migrants or post-breeding individuals occasionally forage or roost on campus. Small numbers nest in natural cavities and woodpecker holes (especially near the Dish), and occasionally in crevices and cavities in buildings on campus.....Similar Species: Tree Swallow ESSAYS: Communal Roosting; Wing Shapes and Flight; Bathing and Dusting; Coloniality REFERENCES: Brown, 1983; Eltzroth and Robinson, 1984; Ersidne, 1984.