MacGillivray's Warbler Superspecies #47 Oporornis tolmiei Townsend       Field Guide IDs: NG-382; G-290; PW-pl 51; AW-pl 411; AM(III)-174 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F? I: 11 DAYS ALTRICIAL 2 feet - 3 feet (1 foot - 5 feet) GROUND MF? 4 (3-5) MONOG F: 8-9 DAYS MF BARK GLEAN GROUND GLEAN BREEDING: Dense thickets (esp riparian willow and alder), edge of coniferous or mixed woods. ? broods. DISPLAYS: ? NEST: Usu close to ground in thick shrubbery; of weed stems, grass, lined with fine materials. EGGS: White to creamy, marked with browns. 0.7" (18 mm). DIET: Little known, mostly insects. juveniles in CO often take sap from Red-naped Sapsucker wells excavated in willows; visits are frequent but short, as sapsuckers chase warblers away. CONSERVATION: Winters from c Mexico s to Panama. Uncommon cowbird host. NOTES: Hybridizes with its eastern equivalent, the Mourning Warbler, where ranges overlap. Hops, unlike similar looking Connecticut Warbler, which walks. Solitary and often territorial on wintering grounds. STANFORD. NOTES: ESSAYS: Hybridization; Superspecies; Wintering and Conservation; Determining Diets; Walking vs. Hopping REFERENCES: Hutto, 1981.