Orange-crowned Warbler Vermivora celata Say       Field Guide IDs: NG-368; G-274; PE-240; PW-pl 51; AE-pl 456; AW-pl 511; AM(III)-116 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F? I: 12-14 DAYS ALTRICIAL 0 - 3 feet F? 4-5 (3-6) MONOG F: 8-10 DAYS MF(?) FRUIT NECTAR TREE SAP BREEDING: Decid and decid-conif woodland, chaparral, riparian woodland. ? broods. DISPLAYS: ? NEST: Usu hidden on ground, but in s CA (occ elsewhere) low in shrub or vine; of coarse grass, bark strips, lined with fine materials. EGGS: White, marked with reds or browns; often mostly at large end. 0.6 (16 mm). DIET: Includes berries, plant galls. CONSERVATION: Winters s to Guatemala. Rare cowbird host. Occ visits hummingbird feeders. NOTES: Widespread and fairly common (esp in w) but many details of breeding biology largely unknown. Regularly feeds at Red-naped Sapsucker wells. Often feeds on floral nectar in tropical wintering areas. Reproduction by blood-feeding lice found only on Orange-crowns is triggered by the birds' own reproductive hormones; synchronized breeding by parasites and their hosts maximizes dispersal opportunities for lice onto uninfected hosts (i.e., nestlings). STANFORD. NOTES: Uncommon migrant in various habitat types throughout campus. May breed in woodland and scrub near the Dish. ESSAYS: Birds in the Bush; Disease and Parasitism; Bills; Mobbing; How Do We Find Out About Bird Biology? REFERENCES: Foster, 1969; Harrison, 1984.