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.

Finch vs Sparrow

I see that my bird classification skills are sadly out of date.  Today I found out that the Indigo Bunting is grouped with the Cardinals, Rose-breasted and Black-headed Grosbeaks, and Flame, Scarlet, and Hepatic Tanagers.  How confusing!  For some reason, I have always lumped little birds with conical (finchy) bills into one group, when in fact, there are definitely two:  finches and sparrows (and then of course, one can further split those two categories into old world (Europe-Asia) and (New World – Americas), but I won’t go there in this post.

So, here’s the low-down on what to call the little finch-like birds in your garden.  (Like all rules, there are, of course,  exceptions to these generalities.)

1) If the male is brightly colored in his summer plumage but the female duller, resembling the winter plumage, the species is likely to be a finch, e.g., Goldfinch, House Finch, etc.

This male hasn’t quite finished decking himself out in yellow and black, but he’s close.

Male House Finches really stand out at this time of year.

Female House Finches have some nice stripes, but lack the brilliant red accent colors of the male.

2)  Sparrows of both sexes sport a mottled brown, black, and white plumage that blends in nicely with their preferred grassy habitat.  Only the juvenile (first year after hatch) birds look different than the adult plumage.

This Swamp Sparrow was singing up a storm, but it was hard to locate him among the dead cattail stems and grasses.

Male and female White-throated Sparrows look identical, but the first year birds have brown head stripes and lack the yellow spot above the eye.

3) Typically, sparrows feed mostly on the ground, scratching under the litter for seeds or insects, while finches are more arboreal, searching for food on the seed heads of perennial grasses, thistles, etc.

Even though there is a feeder full of delicious finch seed right above this bird’s head, it prefers to look in the grass for fallen kernels rather than perch on the feeder.

A photo from last summer illustrates the plumage difference between male and female Goldfinches, as well as their preference for perching on the flower heads to harvest the seed.

4) It may be difficult to see differences in the shape and size of their bills, but finches generally have a stouter, thicker bills for their body size than sparrows.  That rule seems to work if you compare House Finch bills to those of Swamp Sparrows, but it looks like White-throated Sparrows have a pretty thick bill as well.

As I said above, there are exceptions to every rule…but at least I won’t be calling all seed-eating birds sparrows now without thinking about it first.