Cliff Swallow Petrochelidon pyrrhonota Vieillot       Field Guide IDs: NG-324; G-218; PE-202; PW-pl 43; AE-pl 330; AW-pl 353; AM(II)-304 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy BRIDGE GOURD MF I: 14-16 DAYS ALTRICIAL CLIFF BUILDING 3 feet + MF 4-5 (3-6) MONOG F: 21-24 DAYS MF BREEDING: Open country, savanna, esp near running water. Usu 1, occ 2-3 broods. DISPLAYS: Courtship flight followed by cop on ground. NEST: Plastered on underside of bridge or culvert, on cliff, wall under eaves, or other vertical surface; of mud pellets, tubular entrance to a spherical cavity sparsely lined with grass, feathers. Built in 5-14 days. Often repaired and reused. EGGS: White, creamy, or pinkish white, spotted with brown. 0.8" (20 mm). DIET: Almost entirely insects, but occ gorge on berries. CONSERVATION: Winters in S.A. from Paraguay and c and s e Brazil, S to c Argentina. Blue List 1976-77, 1981, Special Concern 1982, Local Concern, 1986; status unclear in n e. Rare cowbird host. House Sparrows usurp nests. NOTES: Nest in colonies, occ to >1,000 pairs. Colonies serve as information centers for good foraging spots: unsuccessful foragers observe successful foragers feeding nestlings and follow them from colony. Colony site occ alternated between years to avoid heavy infestations of nest parasites. Mutual vocal recognition between parents and offspring occurs shortly before fledging. Occ forage with Barn Swallows. STANFORD NOTES: Common resident from spring through fall, foraging aerially throughout campus. Large colonies in the Main Quad comprise most of the campus's breeding population, although a few pairs build their mud nests on residences and other structures. Nests are occasionally appropriated by House Sparrows. ESSAYS: Parasitic Swallows; Parent-Chick Recognition; Coloniality; Blue List; Disease; Masterbuilders. REFERENCES: Beecher et al., 1985; Brown, 1986; Brown and Brown, 1986; Withers, 1977.