The other day we looked at the distinguishing characteristics of the male Purple Finch versus the male House Finch. As I mentioned in that post, the two species are often difficult to differentiate, with the females being particularly confusing. Let’s take a look at how to tell these closely related birds apart.
A primary key for identifying the female finches lies in their markings. The Purple Finch has more clearly defined markings, with more contrast on the head, including a light eyebrow and relatively dark cheek. The House Finch is more uniform in color, and where it has markings, they tend to be less clearly defined. Also keep an eye out for the undertail coverts; Purple Finch coverts are plain white, whereas House Finches show some streaking under the tail. I also sometimes detect a slight yellow coloration in the Purple Finch (see above), but this is inconsistent.
Another distinguishing characteristic lies in the structure of the tail. Purple Finches have shorter tails with a distinct, deep notch, whereas House Finches have longer tails with only a subtle notch.
And finally, even though both species have bills that are characteristic of seed eaters, the Purple Finch’s bill is longer and more clearly triangular in shape. By comparison, the House Finch’s bill is shorter with a more obviously curved upper mandible.
These two birds are easily confused at first glance, but once you have some practice keying in on the characteristics listed above, positive identification becomes much easier.