Tiny, Twittering Bushtits

At only three inches long, tiny Bushtits (Psaltriparus minimus) might go unnoticed by most, flitting through the foliage in loose flocks.  But once you've learned their diminutive calls you'll begin to notice the lively twittering of these little songbirds in suburban backyards as well as wilderness areas of the Great Central Valley.  They move almost constantly as they forage for small insects in shrubs and trees across the western United States, and are often found in flocks associating with other small, sprightly songbirds, such as kinglets, warblers and chickadees. 

 

 

Female bushtits can be distinguished from males by their pale eyes (pictured above and below); male bushtits have entirely dark eyes.  Together, the male and female of a breeding pair build a hanging nest that looks sort of like a dirty gym sock hanging in a tree (at first glance, of course).  The nest is about a foot in length, and the building process can take over a month to complete. 

 

The sack-like nest is built using stretchy spider webs and plant material.  The birds use their weight (all 5 grams of it!) to create the elongated shape by sitting in the nest letting gravity pull it downward. The inside of the nest is lined with soft material, like downy plant material, fur and feathers, while the outside is cleverly disguised with bits of lichen and other nearby plant matter.  

 

A female Bushtit outside her nest in a Valley Oak.  Notice the round entrance hole near the top of the nest.

Interestingly, other adult bushtits help the breeding pair raise its young; more interestingly, these adult "helpers" are generally males.  During the breeding season while the nest is in use, all members of this family-like group will sleep together in the nest.  Once the young have fledged (left the nest), the birds roost in trees at night.  Groups of bushtits may huddle together for warmth during cold weather.  Bushtit flocks change their ranges throughout the year in a constant hunt for food, but they don't truly migrate.

Bushtits are not showy birds by any means, but they are abundant.  Listen for the soft, continuous chipping or "lisping" communication calls of bushtit flocks, and expect to see these cute little birds throughout much of California all winter.