Photo above by Eugene Beckes on FlickrThe varied thrush is the second of our two larger thrushes, along with the American robin (some outdated names include “winter robin” and “mountain robin”). But where the robin is familiar, the varied thrush is mysterious. While everyone knows robins, to most people in our latitudes the varied thrush is as practically nonexistent as the Formosan clouded leopard. And even to those birders who seek them out in their shadowy forest retreats, they maintain a hard-to-dissipate aura of intriguing insubstantiality, as if they could melt back into the shadows at any moment and disappear from human observability, as they more or less can. Breeding in the temperate rainforests of the Pacific Northwest, varied thrushes then travel south along the California coast, spending the winter in our forested regions in somewhat variable numbers. Once in a while, some conjunction of unfavorable conditions in areas to the north will send a greater number than usual of varied thrushes our way. Then people come into the bird shop, asking “what is this striking, good-sized, striped and orange-breasted apparition in my yard?” Out of place, exposed to sunlight, they stand out, impress anyone as belonging to a different class of being than mundane blackbirds and towhees, or bright but frivolous house finches and goldfinches. They are noticed when they appear outside of the forest. Within it, they are easily overlooked by the unaware, but if you see them there all their magic is amplified and expanded, moving with them like an enveloping odor. The darker and shadier, the more they like it. Look for them in forests of redwood, douglas-fir, and bay, overflowing into neighboring live oak-bay woodland of suitable density and consequent capacity for atmospheric mystery. Here in Novato, the best places to look for them are Indian Tree and Indian Valley Open Space Preserves, our two preserves on the northern, and hence shadier, moister, and more forested side of Big Rock Ridge. In Indian Valley, look particularly in the regions of thick bay coverage near Arroyo Avichi along the Ad & Gloria Schwindt trail on the northern end of the preserve. Even in years of relative thrush scarcity, you can usually find a few in these places. In years of moderate thrush abundance, they will appear throughout these parks, as well as in any moderately dense live oak forest at Olompali, Mount Burdell, and elsewhere. As winter visitors, we rarely get to hear the varied thrush sing. And their winter demeanor, though often loosely social, is essentially quiet, with little of the telltale chatter of their cousins the robins. But, as with many birds, you will occasionally here an isolated burst of song. The “song,” however, of the varied thrush, is unlike that of any other bird, consisting of strange, resonant, metallic quavers. Other birds are terse and unmusical in their songs: Hutton’s vireo, or the California towhee, for example. In comparison to more complexly musical birds, this can seem to bring them down in our estimation, marking them as birds incapable of song, the second glory of their tribe (after flight), condemned to communicate with inarticulate chirps and squeals like other unfortunate lower beings of the animal kingdom. But the song of the varied thrush is not like this.
The Varied Thrush loves rain as a fish loves water; while as for the eternal drizzle, it is his native element and vital air. Sunshine he bears in stoical silence or else escapes to the depths of the forest glade. But let the sun once veil his splendors, let the clouds shed their gentle tears of self-pity, let the benison of the raindrops filter through the forest, and let the leafage begin to utter that myriad soft sigh which is dearer than silence, and our poet Thrush wakes up. He mounts the chancel of some fir tree and utters at intervals a single long-drawn note of brooding melancholy and exalted beauty, a voice stranger than the sound of any instrument, a waif echo stranding on the shores of time. There is no sound of the northwestern woods more subtle, more mysterious, more thrilling withal, than this passion song of the Varied Thrush.
– William Leon Dawson, The Birds of California, 1923It is not a chirp, a squeal, a whistle, or a cry. It is simple, but still musical: a gong, a chime, a resonating touch on a harp string. And when you are fortunate enough to hear not just one bird, but many, when you chance to be in the right piece of forest in the right year, when some mysterious and scarce comprehensible confluence of atmospheric portents simultaneously strikes a group of thrushes into one mind and one feeling, then you will hear the forest canopy ring out not with one touch of the strings, but with a cascade, as if your ear was bent low to the undampened piano as every miraculous overtone vibrated from every side of you, while all the while you looked skyward into the backlit, cloudy canopy, seeking the source of those unearthly emanations and seeing only shadows.