Finch Findings, Part 2

Here are the long overdue results of the winter finch quiz from my last post, Finch Findings.

Purple Finch female

Purple Finch female – note the bold eye stripe and heavy streaking (click photos to enlarge)

House Finch male

House Finch male – note the red color is confined mainly to the head and breast area, with brownish streaking on sides

Purple Finch male on pine branch

Purple Finch male – note the raspberry juice color, and hint of a whitish belly. There is also a darkish stripe behind the eye. I also think the bill looks “heavier” than that of a House Finch.

House Finch male 2

House Finch male – note the streaking on the breast

Pine Siskin 1

Pine Siskin – from this angle, it is mainly the streaking and very pointed bill that gives it away

On a less pleasing visual note…while photographing the finches last month, I noticed something I see every few years in the House Finches I encounter.

male house finch - good eye

Male House Finch shows his “good” right eye

One finch landed and looked over his shoulder. After I snapped a quick photo, he turned his head to reveal a problem.

Male House Finch with finch eye disease

Male House Finch with House Finch disease

His left eye was swollen and red, an indicator of an eye disease known as House Finch Disease, or Mycoplasmal conjunctivitis. The disease is caused by a strain of bacteria that previously was known to infect only poultry and pigeons. It was first noticed in House Finches in the Washington, D.C. area in 1994. It spread rapidly through the House Finch population in the East and then was discovered in finches in their native western U.S. range in 2004.

Female House Finch with finch eye disease

Female House Finch with House Finch Disease

Birds can apparently recover from the disease if they don’t starve or get killed by predators (it certainly impacts their vision and thus their feeding efficiency and predator avoidance) but they are still carriers of the disease. It is transferred by direct contact with other birds, especially when flocking together in winter and congregating at feeders. Researchers say that the disease has cut the booming population of House Finches in the East by as much as half, but that now appears to have stabilized. While it is mainly found in House Finches, the disease has occasionally been seen in other finch species like American Goldfinches and Purple Finches. One source recommends periodically cleaning your feeders with soapy water and a mild bleach solution to help reduce this and other bird diseases.


Finch Findings

This winter’s theme is a “mixed bag” of finch movements.

~Ron Pittaway, Ontario Field Ornithologists

Purple Finch male at feeder 1

Male Purple Finch at feeder (click photos to enlarge)

After seeing the first Purple Finches at my feeder a few weeks ago, I started searching online for some information. I ran across one of those interesting combinations of technology and old-fashioned field observations that seems so common in the birding world – Ron Pittaway’s Winter Finch Forecast 2014-2015. Winter finches are birds of far northern forests and include Purple Finches, Grosbeaks (Pine and Evening), Redpolls (Common and Hoary), Crossbills (Red and White-winged), and Pine Siskins. What all of these birds have in common is that they are primarily seed eaters, and in the northern forests, the key tree species for them are spruces, birches, and mountain ashes. Ron and his collaborators do extensive surveys every year and assess the status of the seed crop of these tree species and use that to predict southward movements of the various finches. And they are usually spot on…2012-2013 was predicted to be a great finch year down south (and it was), and last year he predicted a poor one due to abundant seed crops. And, indeed, last year, I did not see a single Purple Finch or Pine Siskin.

Pine Siskin

Pine Siskins are small, streaky, finches with a very pointed bill, and hints of yellow on their wings.

So, this year Ron predicts Purple Finches will move south in decent numbers, along with scattered Pine Siskins, but many of the other species will show limited southward movements due to good crops of certain tree seeds. As I write this, there are about a dozen Purple Finches on the feeder outside my window. I have seen one (an odd number as they usually come in small flocks) Pine Siskin thus far this winter. One non-finch species Ron suggests will move south in moderate numbers this year is the Red-breasted Nuthatch, another seed eater.

House Finch male 1

House Finch male

I think many backyard bird-watchers have some difficulty in identifying our finches, especially in separating the more urban-dwelling, year-round resident, House Finch, from the irregular winter visitor, the Purple Finch. House Finches are a common feeder bird in the East after having been released in New York City in 1940 from a stock brought from their native range of the West Coast for the pet trade. They nest and feed in areas near human habitation, but I see more out along the power line some winters, which indicates, they too, probably undergo winter migrations in especially cold weather. Male House Finches have varying amounts of red on their head and back, a red eyebrow, throat, and upper breast, brownish streaks on their sides and belly, and a square or slightly notched tail. The amount of red is variable because it depends on the individual bird’s diet (red pigments in bird feathers come from a class of compounds called carotenoids, found in plants).

Purple Finch male on branch

Purple Finch male

Male Purple Finches are more wine-red on their head, breast, sides, and rump, and have a white belly and strongly notched tail. The famed ornithologist, Roger Tory Peterson, described the male Purple Finch as looking like a sparrow dipped in raspberry juice.

House Finch female 1

House Finch female

Females of the two species are a bit more difficult to distinguish. House Finch females have brown upperparts with some streaking, and brownish white underparts with faint brown streaks.

Purple Finch female 3

Purple Finch female

Purple Finch females have brown upperparts, and white underparts that are more boldly streaked with brown. But to me, the most distinctive difference is the bold, white eyebrow stripe on the female Purple Finch (lacking in the female House Finch).

So, here is a little quiz to help you identify those birds you may be seeing at your feeders this winter. Answers will be posted later in the week.

Purple Finch female House Finch male Purple Finch male on pine branch House Finch male 2 Pine Siskin 1

Good luck!