Hairy Woodpecker Picoides villosus Linnaeus       Field Guide IDs: NG-282; G-200; PE-192; PW-40; AE-pl 340; AW-pl 365; AM(II)-236 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy MF I: 11-15 DAYS ALTRICIAL SNAG 4 feet - 60 feet MF 4 (3-6) MONOG F: (24?) 28-30 DAYS MF BREEDING: Decid or conif forest, wooded swamps, orchards, woodland, well-wooded towns and parks. 1 brood. DISPLAYS: Pair bonds formed in winter. Duet drumming; female may tap at symbolic (unsuitable) nest site or at suitable sites, and perform quivering, fluttering flight to attract male. Many apparent courtship displays may be aggressive or appeasement. NEST: Excavation takes 1 - 3.5 weeks (averaging 20 days). Usu annual. Lined with chips. Male usu selects site. EGGS: White. 1.0" (25 mm). DIET: Insects (75% to 95%), sap from sapsucker hole. Winter diet includes acorns, hazelnuts, beechnuts. May cache insects. CONSERVATION: Winter resident. Blue List 1975-82, Special Concern 1986; widely reported as declining. NOTES: Female incubates in day, male at night; female does most of brooding. Male forages away from nest, making few visits but brings large prey; female feeds at start and end of day, foraging within hearing distance of young and making frequent trips. Parental care continues several weeks beyond fledging. Nest cavities often appropriated by House Sparrows and starlings. Males tend to forage higher than females in winter. STANFORD. NOTES: ESSAYS: Island Biogeography; How Do We Find Out About Bird Biology?; Nonvocal Sounds; Hoarding Food; Who Incubates? REFERENCES: Kilham, 1968, 1969, 1983; Morrison and With, 1987.