House Wren Troglodytes aedon Linnaeus       Field Guide IDs: NG-334; G-236; PE-214; PW-pl 46; AE-pl 486; AW-pl 529; AM(II)-350 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy FM? I: 13 DAYS ALTRICIAL SNAG 0 - 20 feet + MF 6-8 (5-12) MONOG (POLYGYN) F: 12-18 DAYS ? INVERTS FOLIAGE GLEAN BREEDING: Open woodland (esp in w), shrubland, farmland, suburbs. 2, rarely 3 broods. DISPLAYS: Courtship: male sings while quivering wings, tail raised; female quivers wings. Often male has already started nests, and dual nest inspection follows. NEST: Usu in natural hole, occ in nests of other birds, variety of other cavities. Of twigs, grass, lined with fine materials. EGGS: White, marked with browns, occ wreathed. 0.6" (16 mm). DIET: Includes millipedes, spiders, snails. CONSERVATION: Winters s throughout Mexico. Rare cowbird host. Readily uses nest boxes. NOTES: Male often builds crude "dummy" nests. Males exhibit strong fidelity to breeding territory. Both male and female often destroy eggs of other House Wrens and of other species nesting nearby; this behavior is inhibited while birds are tending their own eggs. Carolina Wrens, House Sparrows, and European Starlings compete for nest holes. STANFORD. NOTES: Uncommon migrant and summer resident in wooded areas near the Dish, nesting in natural cavities, old woodpecker holes, and nest boxes. Uncommon to fairly rare migrant elsewhere on campus. ESSAYS: Incubation: Heating Eggs; Polygyny; Eggs and Their Evolution; DDT and Birds; Site Tenacity REFERENCES: Belles-Isles and Picman, 1986.