April 4, 2022
Having been out of town for the entire month of March it is very exciting to return to find spring is well on its way here. There are flowers blooming along the roadsides such as Lupines and Buttercups. The vibrant green of the Willits Valley is soothing to my eyes and psyche. As I step out into the riparian habitat along Outlet Creek, my ears are filled with the exciting sound of spring birds calling and singing. The Orange-crowned Warblers, Leiothlypis peregrina, are everywhere along the creek singing their rapidly trilling song that can sound like a Chipping Sparrow or even a Dark-eyed Junco, but unlike their more staccato even trills, it has a distinctive descending pitch at the end.
This warbler is generally a lovely yellow-olive color with a faint eyeline and always has yellow undertail coverts. The eastern subspecies are not as brightly colored as our western subspecies and in both cases the females are duller and less olive green than the males. Their bill is small, fine, and pointed. Since they eat mostly small invertebrates such as ants, beetles, flies, and caterpillars, this type of bill is handy. In the winter they supplement their diet with fruits, berries, seeds, and visit the sapwells drilled by sapsuckers and other woodpeckers.
The Orange-crowned Warbler is not the most beautiful of our warblers, but it is one of the earliest to arrive and the last to leave in the fall. The Cornell website All About Birds states, “that they are a medium to long-distance nocturnal migrant. Many Orange-crowned warblers winter in Mexico, with some continuing south to Guatemala and Belize. Others winter in central California and the southern U.S. This is another cool fact from the Cornell website: The male Orange-crowned Warbler’s song is far more variable than that of other wood warblers—so much so that individual males can be told apart by their distinctive song patterns. Breeding males often form “song neighborhoods,” where two to six birds in adjacent territories learn and mimic each other’s songs. These “neighborhood” songs can persist for years. Their song is just as complicated as some other warbler species, but the fact that the male birds have unique songs has me listening carefully to the ones that live around my house.
I have seen very few Orange-crowned warblers around during the winter but when I begin to hear their song in early spring, it is as if a faucet has been turned on and they are everywhere. Since these warblers are found in many habitats that we have in Mendocino County and here in Little Lake Valley, their song is ubiquitous. According to Cornell, “Overall they breed in more forest types than nearly every other warbler species.” In Willits, I have seen them frequently in the city park, walking down Main Street, and in Brooktrails and other surrounding areas.
One of the most amazing things for me about Orange-crowned warblers is that they nest mostly on or near the ground. The nests I have found have literally been right next to a frequented walking path. It seems like such a vulnerable placement, but it seems to be their preferred type of spot to build a nest. They are hidden from view, quite cleverly, and blend in well with the scrubby environment along the path. As you are outside this spring listen to the changing sounds around you and see if you can pick out the trill of the Orange-crowned Warbler telling us that nesting is beginning in the bird world. Be careful where you are walking and pay attention to what the birds are doing, you may find a hidden nest.