Common Yellowthroat Geothlypis trichas Linnaeus       Field Guide IDs: NG-388; G-288; PE-246; PW-pl 51; AE-pl 371; AW-pl 419; AM(III)-176 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F I: 12 DAYS ALTRICIAL 0 - 3 feet F 3-5 (3-6) MONOG (POLYGYN) F: 10 DAYS MF HOVER & GLEAN BARK GLEAN HAWKS BREEDING: Overgrown fields, hedgerow, woodland margin, freshwater and salt marshes. 2 broods. DISPLAYS: Courtship: male follows female closely; occ performs flight display: ascends from low perch to 25'-100', swoops to another low perch giving call notes and garbled song. NEST: Bulky, loosely made of weed stems, grass, bark, ferns, lined with fine materials. EGGS: White to creamy, marked with browns, black, occ wreathed. 0.7" (18 mm). DIET: Includes spiders; few seeds. Occ gleans from ground. CONSERVATION: Winters s to Bahamas, West Indies, and s to Panama. One of the three most frequent cowbird hosts. NOTES: Perhaps the most abundant warbler. Female leaves nest unobtrusively; does not perform distraction display. Young remain dependent on parents for longer than most warblers; second brood may be fed up to migration time. May begin migration as family group. STANFORD. NOTES: Uncommon to fairly rare migrant in brushy habitats and tall weedy vegetation, especially near water. Occurs most regularly near Lagunita and, during migration, in scrub near the Dish. Breeds in the Stanford vicinity; marginally suitable nesting habitat may be present around Lagunita in some years, though suitable wetland breeding habitat is generally absent from campus. ESSAYS: Vocal Functions; Bathing and Dusting; Cowbirds; Distraction Displays; Parental Care. REFERENCES: Wunderle, 1978.