Bushtit

Psaltriparus minimus
STANFORD LOCATIONS:

Common to abundant resident throughout campus in a wide variety of habitat types. Often found in large flocks, occasionally exceeding 50-75 individuals, throughout most of the year (except early in the nesting season).
  
Nest
Location
Nest
Type
Eggs
Mating System
Dev.
Parental Care
Primary &
2ndary Diet
Foraging
Strategy
M F
I: 12 DAYS
ALTRICIAL
SHRUB
 4 feet- 25 feet
(To 50 feet)
MF
5-7
MONOG
F: 14-15 DAYS
MF
SEEDS
FRUIT
BARK GLEAN
BREEDING: Woodland, scrub, chaparral. 2 broods.
DISPLAYS: Courtship of calls, trills, and posturing.
NEST: Gourd-shaped hanging pocket, woven around and supported by twigs; of moss, lichen, leaves, cocoons, grass, flowers, secured by spider web, lined with plant down, hair, feathers. Built in 13-51 days.
EGGS: White, unmarked. 0.6" (14 mm).
DIET: Includes spiders. Young fed undigested, solid food.
CONSERVATION: Winter resident. Rare cowbird host.
NOTES: Pairs disturbed during nest building, egg laying, or incubation often desert, change mates, and build new nest. When clutch complete, male and female roost in nest. Both sexes brood. Pair show high tolerance for other Bushtits in territory, allowing them to forage and even take part in nesting activities. Highly gregarious except when breeding, moving about in family groups after nesting, then in loose flocks of 6-30 (up to 70), often associates with kinglets, wrens, titmice, warblers, and chickadees. Groups roost huddled in tight mass, saving energy from reduced heat loss. Iris of eye is pale cream in adult females, dark brown in juveniles and adult males. Populations in s w with black-eared males previously regarded as separate species, Black-eared Bushtit.
ESSAYS: Metabolism; Bird Guilds; Birds, DNA, and Evolutionary Convergence; Eye Color; Mixed-Species Flocking; Temperature Regulation.
REFERENCES: Chaplin, 1982; Ervin, 1977.

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Except for Stanford Locations, the material in this species treatment is taken, with permission, from The Birder's Handbook (Paul Ehrlich, David Dobkin, & Darryl Wheye, Simon & Schuster, NY. 1988).