It’s unmistakably autumn when the strikingly beautiful varied thrush begins appearing in Pacific Northwest yards, parks, and natural areas. That’s varied, as in Ixoreus naevius, though I’ve also seen various other thrushes—Swainson’s and hermit—feeding in residential areas from time to time. The scientific name given to this robin-sized bird comes from the Greek ixos, which means “mistletoe,” and oros for “mountain” and the Latin naevius, which translates to “spotted or varied.” If my math is correct, that adds up to “varied berry-loving mountain bird,” or some such.
Since reading the State of the Birds 2014 report I’ve felt a twinge of anxiety about whether or not I’d see them this year, as I have each fall and winter since I began creating our “real” garden. Sadly, the varied thrush is one of 33 species included on the list of “Common Birds in Steep Decline” that have lost more than half of their global populations within the past 40 years. But just a few days ago I spotted a female rummaging on the ground through the leaf litter and compost in our vegetable beds, as if she had forgotten where she put her keys. She’d grab a dry leaf in her bill, toss it aside as she hopped backwards, and then search the ground. She was looking for dinner, of course, and apparently found some tasty morsels in the form of insects or slugs that were hoping to get through the winter under protective leaf litter. Varied thrushes also eat fruit and nuts (primarily acorns) during winter and I wondered when she’d return to find the rose hips, patiently dangling off my clustered wild rose (Rosa pisocarpa), as she (or her cousin) had done last year. Apples are also reportedly a favorite food in fall.
Most thrushes wear earthy colors on purpose—so they can be difficult to spot—but this species can be especially tough to see since their gorgeous plumage is reminiscent of dappled sunlight or pumpkin-colored leaves on a forest floor. And they’re timid around people, so you may be more likely to hear one than to see one. But hearing their call in a forest rarely helps locate one, since their ethereal, somewhat mournful voice seems to pervade the woods. Let’s honor their need to be left alone: sometimes it’s enough just to hear them to be struck by their beauty, isn’t it?
Birds of a feather
Fall through winter, varied thrushes gather together in flocks, collectively known as a hermitage—a fitting description considering their obligation to be concealed. I’ve never seen more than three at a time in my yard, so their flocks must be a loose assemblage. In the city they act a bit bolder, coming to within 20 feet of the house to feed, as well as perch and survey in leafless trees. Their range encompasses the boreal forests of Alaska and the Yukon southward along the west coast to California and east to Alberta, Idaho, and western Montana. National Geographic records their winter range as “coastal Alaska to southern California and parts of northern Rockies,” but judging by this enthusiastic news account, sightings in southern California may be somewhat rare.
During the remainder of the year, varied thrushes retreat to mature, misty, hushed forests dominated by tall conifers and lush ferns, and dine on mostly insects and other arthropods. Many migrate north as the days lengthen. In spring, the female creates her nest in streamside shrubs or conifers, typically 5 to 15 feet above ground. According to the Cornell Lab of Ornithology, “The female gathers nest material and weaves an outer layer of fir, hemlock, spruce, or alder twigs. She adds a middle layer with rotten wood, moss, mud, or decomposing grass, which hardens into a dense cup about 4 inches across and 2 inches deep. Finally, she lines the cup with fine grasses, soft dead leaves, and fine moss, and drapes pieces of green moss over the rim and outside of the nest.” Two to six, blue, specked eggs are laid and incubated by mom but the hatchlings are tended by both (monogamous) parents; they fledge in about two weeks. They are fed arthropods, as are most land birds. Two broods are produced when possible.
Since these birds thrive in old growth forests, logging is having a profoundly negative impact on their numbers, as will climate change. Window strikes are also responsible for many deaths. Want to help them and see them in your yard?
◊ During fall and winter, don’t rake away the leaves, twigs, bark, and other dead wood that fell from trees onto the soil.
◊ If your yard was historically forest, grow the trees that likely once grew there to provide food and roosting or nesting sites. In coastal B.C., Washington and Oregon, choose Sitka spruce (near the coast), Douglas-fir, western hemlock or western red cedar; in northwestern California choose coastal redwood, Sitka spruce, and red alder.
◊ Thrushes are mainly insectivorous, so add additional native plants that would naturally occur with the trees to supply extra helpings of insects.
◊ Include natives that produce fruits, nuts, or seeds to provide additional forage. Depending on your location, madrone, cascara, garry oak, wild rose, huckleberry, elderberry, honeysuckle, salal, thimbleberry, and dogwood might be good choices.
◊ Be sure birds can see your window glass, not a reflection of the sky. Some tips to help birds avoid reflective glass.