Pine Siskin Carduelis pinus Wilson       Field Guide IDs: NG-452; G-320; P-272; PW-pl 55; AE pl 557; AW-pl 598; AM(III)-338 Nest Location Nest Type Eggs & Mating System Dev. & Parental Care Primary & 2ndary Diet.. Foraging Strategy F I: 13 DAYS ALTRICIAL DECIDUOUS TREE 8 feet - 50 feet (3 feet - 50 feet) F 3-4 (1-5) MONOG F: 14-15 DAYS MF INSECTS GROUND GLEAN BREEDING: Conif and mixed conif-decid forest, woodland, parks, suburbs. 2? broods. DISPLAYS: Courtship (begins prior to breakup of winter flocks): male spreads tail, flaps wings rapidly while circling over female during flight song. Courtship feeding. NEST: On horizontal limb well out from trunk; of twigs, rootlets, grass, lined with fine rootlets, moss, fur, feathers. Female chooses site. EGGS: Pale greenish-blue, spotted with browns, black, usu wreathed. 0.7" (17 mm). DIET: Includes seeds of decid and conif trees, forbs, and grass, floral buds and nectar (of trees), sap. CONSERVATION: Winters s to n Mexico; migrates altitudinally in some areas. Uncommon cowbird host. Fondness for road salts leads to many deaths from automobiles. NOTES: Often semicolonial, only few feet between nests. Social all year, often feeds in small groups in breeding season. Male feeds female on nest from incubation to few days after hatching; during latter period, male supplies food to female for nestlings. When foraging in flocks, birds tend to move down from top of tree in compact group, then move in circular flight to another tree and repeat. Winter flocks usu 50-200, occ to 1,000. Nomadic in fall and winter; feeds in mixed flocks, esp with goldfinches, juncos, crossbills. STANFORD NOTES: Irregularly uncommon to fairly rare migrant and winter resident throughout campus. Virtually absent in some winters but present in flocks (often at feeders or on conifers) in others. ESSAYS: Irruptions; Birds, DNA, and Evolutionary Convergence; Mixed-Species Flocking; Courtship Feeding. REFERENCES: Bent, 1968.