It can be a startlingly beautiful experience this time of year when you see a sudden flash of brilliant cobalt blue against the muted winter landscape. In the Blue Oak woodlands and Valley Oak savannahs of the Tehachapi Mountains, this usually means one thing: Western Bluebirds.
These small thrushes are found locally year-round, but they are especially noticeable when the deciduous trees are not clothed in concealing leaves. This is also the time that male Western Bluebirds in particular start showing their most vibrant, color-saturated plumage in preparation for the upcoming spring mating season.
Some of the most ubiquitous birds are used for size comparison purposes — for example, bird books will often describe a bird as "the size of a sparrow" or "robin-sized." Western Bluebirds fall between these two categories, being slightly larger than sparrows but smaller than robins.
As usual among songbirds, it is the males that are flashier, and male Western Bluebirds sport a gorgeous blue color on their head, wings and tail. They also have a rusty-orange or fawn color on their chest and back reminiscent of the robin breast color — and in fact they are distantly related, since robins are also a type of thrush.
The color of female Bluebirds are more drab and subdued, but I think underappreciated. They are grayish-buff colored with overhead sky blue tinting on their wings and tail, coupled with tawny orange on their chests. Some females are more brightly colored than others, but even the paler ones have the subtle beauty of an Andrew Wyeth watercolor.
Western Bluebirds have the short, pointed bill of an insect eater, and that's primarily what they eat, usually ground-dwelling insects like grasshoppers, beetles, caterpillars, assorted larvae, spiders, etc.
Like many insect eaters, Bluebirds switch to eating berries and fruit in winter when cold weather makes invertebrates scarce. Among the berries that Western Bluebirds consume in the Tehachapi Mountains are mistletoe, chokecherries, juniper, elderberry, poison oak and the small berries produced by a variety of cultivated plants.
Western Bluebirds spend much of their time fairly close to the ground, perching in lower oak limbs or on fence posts and fence lines, then darting down to catch prey when they spot something moving.
Western Bluebirds are frequently found not far from Acorn Woodpeckers, another iconic bird of California's oak woodlands. Bluebirds benefit from this association by sometimes utilizing holes that Acorn and other woodpecker species have made in dead limbs. Bluebirds are cavity nesters but not are not capable of excavating holes themselves, so they must use those that occur naturally or are created by creatures better suited for boring.
This reliance on cavities for nesting became problematic with the arrival of House Sparrows and European Starlings, two non-natives who often out-competed Western Bluebirds for the available supply of nesting cavities. This contributed to a decline in Western Bluebirds, which seems to have stabilized and even reversed.
Part of this improvement can be attributed to help from humans in the form of nest boxes, and people have put up tens of thousands of Bluebird nest boxes in the past 40 years. Locally, my brother and I have made and put up more than 50 bluebird boxes, and Karen Pestana has done a wonderful job of maintaining and monitoring a couple of bluebird trails in Tehachapi for many years. For nest box plans, visit the website of the North American Bluebird Society.
Tehachapi News readers send me beautiful Western Bluebird photos from time to time, and I just received some more, including some from Nancy Valle, who lives in the City of Tehachapi not far from the airport. She and her husband, Andy Cortez, have created a lovely tropical-themed garden called Island Breeze, and they had some Western Bluebird visitors during recent stormy weather, enabling Nancy to get an unusual image of a male Western Bluebird on a palm frond. Daniel Curnow and Marsha Morris have also contributed photos of Western Bluebirds in the Golden Hills area, a region these birds love. Marsha has a waterfall feature and bird bath that attracts Bluebirds to her yard year-round.
Have a good week.
Jon Hammond has written for Tehachapi News for more than 30 years. Send email to email@example.com.