Laura Erickson remembers when she first moved to Duluth, exactly 40 years ago, when evening grosbeaks were common visitors to her bird feeders in the Lakeside neighborhood.
“They were here all the time. They nested here. It wasn’t uncommon for us to go through 50 pounds of sunflower seeds in a week,’’ said Erickson, an award-winning bird watcher. “They’re kind of pigs.”
But over the past 30 years or so, grosbeaks have been uncommon visitors to much of the Northland. Some might make their way down from Canada in early winter, maybe as far as the Sax-Zim Bog, where they are commonly seen, but few wandered into Duluth or points south.
Until now. Erickson is back to buying lots of sunflower seeds again.
This past fall and winter, grosbeaks and other members of the finch family invaded, or irrupted, into the U.S. from Canada in huge numbers — more of them and farther south than seen in years.
“This is part of a massive irruption. It’s probably the largest irruption of finches in recent memory. It started last fall and over the winter … and now we’re still seeing it with evening grosbeaks, at least I am, in Duluth,” Erickson said.
Other Duluth birders, including Dudley Edmondson and Frank Nicoletti, also reported numbers of evening grosbeaks in April. Edmondson said he had them around from April 11 to May 11. "They were pretty regular during that time period coming to my feeders nearly daily," he said.
Matt Young, ornithologist and founder of the Finch Research Network, speculated last fall that the big push — some finch scientists were calling it a "superflight" — was caused by a lack of food up north. In addition to evening grosbeaks, the finch invasion included common and hoary redpolls, pine grosbeaks, pine siskins, red and white-winged crossbills and purple finches.
“There were finches way down in the southern U.S in inappropriate places they have never been reported before,” Erickson noted.
Many of those finches already have headed back north. But not all of them. Erickson started seeing a few evening grosbeaks in her yard in mid-April. Within weeks, she saw as many as 250 in a day. She was still seeing large numbers this past week, mostly in the mornings, but a few all day.
“They do not live up to their name,” Erickson said, noting they aren’t as active in the evenings.
Of course, Erickson has exactly what grosbeaks want — namely lots of sunflower seeds available on an open-platform feeder. She also has box elder and maple trees in her yard — the two native tree seeds grosbeaks love most.
Officially, the Minnesota Breeding Bird Atlas, the bible of birds in the state that developed over many years through extensive field work, lists the evening grosbeak as “a regular breeding resident, erratic migrant, and winter visitant in Minnesota. The species was uncommon during the Minnesota Breeding Bird Atlas.”
Because of the 30-year population decline — which was evident across the continent — the evening grosbeak is a species of “conservation concern” throughout North America and is designated as a “Species in Greatest Conservation Need” in Minnesota.
Audubon lists evening grosbeaks as at high risk of having its habitat disrupted due to climate change, with their primary range pushed much farther north in coming decades.
It was never clear why evening grosbeaks stopped hanging around the Northland all year. Some say that the huge numbers back in the 1970s and 1980s was the aberration, that their numbers were usually small here and that the last 30 years is probably the historical norm.
But Erickson isn’t buying that. She believes they were historically common here and that something changed over the last 30 years.
“They were here in numbers enough so there was even an Ojibwe word for them,’’ Erickson noted. “Really, nobody knows what the normal was or why it changed. We just have theories.”
Ericson said insect management to control spruce budworm in Canada and the Northeastern U.S. may be impacting the birds because budworms are a primary food for grosbeaks to feed for their young. Forest disturbances, such as tar sands mining in Alberta, also may be an issue, as are collisions with vehicles on roads and windows in homes.
Now, Erickson — who produces the weekly “For the Birds’’ show on KUMD radio in Duluth and who writes the "For the Birds Blog" at lauraerickson.com — is hoping more people will pay attention and report any evening grosbeaks they see courting to mate or building nests in the Northland. The mating pairs may also be seen feeding each other. (Not fighting for seeds but actually giving seeds to their mate.) She’s hoping an army of citizen scientists can help verify if the grosbeak irruption was just a single-season phenomenon or if the birds may be back to nest and stay.
“They all chatter a lot, so there isn’t a mating call so much. But the male will bow and flutter his wings with his tail straight up in the air” as a courtship ritual, she said. “The biggest sign they are nesting here is if people see them moving nest material around.”
Whatever the reason they showed back up, Erickson hopes more people will get a chance to enjoy the birds while they are here.
“They may all disappear tomorrow, or they may all remain, or some may remain and nest in or around town,” Erickson noted. “The cool thing is that this irruption may result in a whole new decade of plenty. Or it may not. We just don't know. Either way, it'll be both fun and instructive to pay attention.”
For more information on evening grosbeaks in Minnesota, go to mnbirdatlas.org/species/Evening-Grosbeak.
About evening grosbeaks
The evening grosbeak is a songbird without a song; It doesn’t seem to use any complex sounds to attract a mate or defend its territory. It does have a small repertoire of simple calls, including sweet, piercing notes and burry chirps.
Evening grosbeaks use their huge bills to crush seeds that are too large for common redpolls and pine siskins to open. These smaller birds often seek out the grosbeaks and glean the food scraps they leave behind.
Though they’re ferocious seed-crackers in the wintertime, in summer evening grosbeaks eat insects such as spruce budworm, a serious forest pest. The grosbeaks are so adept at finding these tiny caterpillars that the birds often provide a first warning that a budworm outbreak has begun.
Evening grosbeaks are irregular (or “irruptive”) winter migrants. Some years these spectacular finches show up at feeders far south of their normal winter range — providing a treat for backyard bird watchers. By joining Project FeederWatch you can keep track of visits by these and other winter birds — and the data you record will help scientists keep track of bird populations.
The oldest recorded evening grosbeak was a male, and at least 16 years, 3 months old when he was found in New Brunswick in 1974. He had been banded in Connecticut in 1959.
Source: National Audubon Society