Finches of the forest

It was a treat to find two birds we never see in the Twin Cities at the feeders in Sax-Zim bog last weekend.  Evening Grosbeaks and Pine Grosbeaks are the largest members of the finch family, and like other finches, the male is brightly colored and the female is somewhat drab in comparison.

Male (left) and female Evening Grosbeak

Male (top) and female Pine Grosbeak

Both species use their large, crushing bills to harvest seeds out of reach of the smaller finches in the winter, but the summer diets of both are quite varied.

Now that’s a big beak!

Evening Grosbeaks consume a lot of seeds in the winter, but they are largely insectivorous in the summer, especially when feeding chicks.  They are a major predator of the spruce budworm pest.  They are usually found in spruce-pine forests in southern Canada and the mountains of the western U.S. year-round.

Pine Grosbeaks prefer a diet of fruit with their seeds and might feast on crabapples in a residential yard, as well as the sunflower seeds at the feeder.  They breed in the northern-most coniferous forests of Canada, feeding their chicks a mash of insect and vegetation.

The two species are not closely related, and the Pine Grosbeak is actually a circumpolar species, found in pine forests from Scandinavia to Eastern Asia, with its closest relatives being the European Bullfinches.  In North America, both species respond to winter food shortages with irruptive behavior that might involve flying miles south of their breeding territories.  Northern Minnesota is on the southern border of their winter range, so we felt lucky to see them.

funny bird names

Some bird names are completely understandable, based on their coloration (e.g., Black-capped Chickadee or Gray Jay) or some attribute of their exterior anatomy (e.g, Tufted Titmouse, or Spot-winged Grosbeak), or a particular behavior or association with another animal (e.g., Cattle Egret), or even where they are most commonly found (Boreal Chickadee or Carolina Wren).   But some birds have nonsensical names that make you want to look up how their name originated.  Such a bird is the Evening Grosbeak.  Why evening?

This photo is so dark and dreary it might have been shot in the evening, but it is actually mid-day at foggy, cloudy Sax-Zim bog.  Wouldn’t a more appropriate name for this bird have been White-winged Grosbeak? Unfortunately, there is already an asian finch of the same name.

A little research confirms that the bird got its name from the mistaken impression that it “sang” in the evening.  “Sang” in quotes because the bird doesn’t really sing but emits a series of one-note chirps, burbles, and burps at all times of the day. So…my suggestion is it be renamed the “black-capped, yellow-browed, black and white-winged Grosbeak” (and that should take care of identifying it).

Like other finches, male and female Evening Grosbeaks have distinct plumage differences. For description of what constitutes “finchiness”, see my post on Finch vs Sparrow

Evening Grosbeaks and Pine Grosbeaks (which we also saw on this trip north) are members of the Finch family, although several other Grosbeak species (e.g, the familiar Rose-breasted Grosbeak we see in the spring and summer) are members of the Cardinal family.

Chow time at the sunflower feeder.  The female lacks the golden yellow colors of the male.

Their big crushing bill is quite useful for cracking the large seeds that smaller finches like Pine Siskins and Goldfinches cannot manage. Typically, Evening Grosbeaks eat seeds in the winter but switch diets to become highly insectivorous in spring and summer. This implies that their gut anatomy and physiology makes some marked seasonal shifts as well.

Although their winter range covers much of the U.S., these birds usually hang out in coniferous forests when not visiting bird feeders, and they prefer to nest in spruce forests at northern latitudes or high altitude.  That probably explains why I haven’t seen them in my backyard.