The last leg of my morning commute takes me from the Museum’s parking lot to the front doors. Though short, this walk is often filled with birdsongs. Chickadees can always be counted on, blue jays shout their alarm, and house finches twitter from the neighbor’s cedar trees in the spring. One morning last week there was a chorus of sweet, arrhythmic calls coming from the hedge of boxelder trees by the street.
It was a gray morning, with just enough sun to silhouette the trees. When I stopped moving, their fluttering revealed a dozen or so robin-sized birds. As I watched, they plucked at the maple-like boxelder seeds in their large, pale bills. Discarded seed wings littered the snow beneath the tree. Squinting from a new angle, I could just make out the bright yellow bellies, black-and-white wings, and yellow foreheads of the male evening grosbeaks in the group. The females would have blended perfectly with the gray sky if it weren’t for black-and-white on their wings.
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| Male evening grosbeaks are bright yellow! Photo by Emily Stone. |
Despite the poor light, I was thrilled! It’s so nice to see their sunny yellows when our local goldfinches have gone drab. In 2023, flocks of a hundred or more evening grosbeaks were spotted at many feeders in the Northwoods—but not mine. This winter, I’ve been watching jealously as my neighbors proudly post photos of small groups of grosbeaks visiting their feeders every few days. My feeders are too small for these big birds, but this tangled mess of boxelder fits their bills.
Evening grosbeaks are colorful members of the finch family. They got their name not because they are the color of the setting sun, but because English settlers thought the birds only came out of the woods to sing at sundown. French settlers reportedly gave them the more accurate name of le gros-bec errant, the wandering grosbeak. These bright birds travel widely toward the best food sources in movements known as “irruptions.”
In winter, evening grosbeaks are attracted to the large seeds of deciduous trees like maples, ashes, and boxelders. In the summer, they seek spruce budworms—the destructive caterpillars of a little brown moth—to feed their chicks. Grosbeaks are so good at detecting spruce budworms (which also feed on balsam fir trees) that an influx of the birds is often humans’ first clue to the start of an outbreak.
But cycles of natural budworm outbreaks and shifts in how much humans try to control outbreaks through aerial spraying, now impact how much baby food grosbeaks have access to from year to year, and decade to decade. It’s not good. According to the Finch Research Network, evening grosbeaks have declined by 92% since 1970. The causes of this decline are not fully understood, but likely stem from changes in both their summer and their winter food sources.
Back in the 1800s, evening grosbeaks were mostly a western species. In the early 1900s they started to move east, mostly in winter, probably due to the marked increase in the popularity of boxelder as an ornamental tree. Then the 1970s saw extensive spruce budworm outbreaks. The dramatic increase in both their summer and winter food at this time may have meant that evening grosbeak populations were unusually high at the start of the period of decline.
Logging, too little or too much management of budworm, and diseases like West Nile likely ended the grosbeaks’ period of abundance. It doesn’t help that evening grosbeaks are the species most commonly killed in window collisions, and they are also hit by cars in high numbers when flocks descend to the roads for salt. They may even be a victim of their own success as the budworms that grosbeaks love to eat sometimes end up destroying the birds’ breeding habitat.
In the 2016 Landbird Conservation Plan produced by Partners in Flight, the evening grosbeak was cited as the steepest declining landbird in the continental United States and Canada. They aren’t listed as endangered yet but have been designated a “species of special concern.” Scientists have come together in an Evening Grosbeak Working Group to fill the knowledge gaps across priority areas like diet, causes of death, migratory and population dynamics, habitat, and climate change.
Among other things, scientists are outfitting grosbeaks with satellite and radio transmitters and colored leg bands to help track their movements. The same MOTUS towers that I wrote about for tracking saw-whet owls in Bayfield Country are also recording radio-tagged grosbeaks! Up in Sax-Zim Bog in northern Minnesota, 75% of grosbeaks who scientists outfitted with solar-powered satellite tags stuck around the spruce-fir forests of this Important Bird Area, while the rest of them journeyed off in all directions.
How can you help? If you see grosbeaks, post your photos to iNaturalist or eBird where scientists can use them as data to determine where the birds are and what they are eating. Or if you’re lucky enough to see one with a colored band, report it to the USGS Bird Banding Laboratory. Learn about ways to prevent birds from colliding with your windows from the American Bird Conservancy. Keep cats inside. Keep your bird feeders clean and take them down if you notice sick birds. Support the Finch Research Network and other conservation organizations with your donations.
Together, networks of scientists and legions of bird-lovers are working to make sure that the Sun isn’t setting on evening grosbeaks.
Emily’s third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.
For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Winter Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.
