By Linda DeKort

The first time I spotted a flock of Evening Grosbeaks at a feeder adjacent to Owen Sowerwine Natural Area, I thought I was witnessing escapees from a tropical bird aviary. The plumage of these stocky robin-sized birds is stunning and unmistakable. The male’s forehead and eyebrows are bright yellow. The crown is black and the breast and lower back are also yellow. Most of the wing is black with a striking white patch. The stubby notched tail is totally black. Our neighbor, Reta Sweeney, describes these males as “the birds in backwards yellow trimmed tuxedos.” Females are duller, but easily identified by the white wing patches and large bill. Females also have white at the tip of their short black tails and white spots on the upper tail. Their name is a misnomer. Apparently the first recorded sighting in 1823 of this heavy-billed species occurred “at twilight”, hence the name: evening grosbeak (Coccothraustes vespertinus). They are actually more active in the morning and often roost for the night as early as 2 pm in the winter.

They are aptly named grosbeaks, having an unusually bulky bill whose color differs in summer (slightly greenish) and winter (bone colored). This powerful triangular bill is fashioned specifically for cracking seeds, which they first roll up on edge with their tongues, then pop in two with a munch of their heavy mandibles. They are especially attracted to black oil sunflower seeds and we used to joke at Flathead Audubon board meetings that it was these gregarious birds with the voracious appetites that kept our seed sales hopping and our coffers full. The food of the evening grosbeak also includes spruce budworm larvae and other insects. In fact, National Audubon reports that the most important consideration for a nest site is the abundance of spruce budworms, which explains why we had several pairs of Evening Grosbeaks nesting adjacent to our spruce stands this summer and we hope they devoured a good number of larvae. As is common with birds breeding at high altitudes, the Evening Grosbeak usually only lays one brood of 2-5 eggs per year. The nests are often high in a tree and difficult to spot; courtship also is a bit secretive with no showy display or song. The nest looks like a flattened loose saucer of small twigs and roots, lined with grasses, twigs, lichens, or conifer needles. The eggs are light blue to blue-green with brown scrawls concentrated on the large end. Nesting dates in NW Montana are early June to late July. When the fledglings emerge by late July, you know that they are here with much raucous rattling and buzzing.

Evening Grosbeaks range throughout the northern US and southern provinces of Canada. They are found in the mountains of the Western US, Canada and Central Mexico. If food is available, in birdfeeders or elsewhere, and winter is not too severe, they may not migrate. We have seen Evening Grosbeaks on our Christmas Bird Counts in this valley for the last decade. I was fortunate to be in Kathy Ross’ group on the Kalispell Christmas Count last month. Her eagle eye spotted a flock of 15 large beaked birds wearing backwards tuxedos out the window of our moving car. One of those hearty souls visited our feeder last weekend, a splash of tropical gold against the winter grey.

Evening Grosbeaks are not doing so well nationwide, however. Christmas Bird Count data were instrumental in development of an Audubon Report in 2007 entitled Common Birds in Decline, which states that some of America’s most beloved and familiar birds have taken a nosedive in the past forty years. The decline of the Evening Grosbeak has been startling: 78 percent in 40 years (3.8 million now as opposed to 17 million in the 1960’s). Because they are birds of boreal and montane forests, they are susceptible to all incursions into those habitats: logging, mining, drilling, acid rain, and human development.

Chemical control of spruce budworm and other tree pests lowers this species’ food supply and may cause secondary poisoning. Competition and the spread of disease among house finches, goldfinches, and other feeder birds may also be playing a role in the decline. Global warming is predicted to cause deforestation due to increases in insect populations and fire frequency. There are many actions we can take to help Evening Grosbeak populations rebound. One of them is to plant Rocky Mountain Juniper which is a native shrub and provides good cover for many songbirds, including Evening Grosbeaks. Another is to stay involved in the monitoring of our local birds through citizen science efforts such as Christmas Bird Count, Backyard Bird Count (coming up over Presidents’ Weekend), and Project Feeder Watch. The National Audubon website offers many other suggestions.