Sparrow or finch - how do you tell?

Some sparrows and finches are easily identified because of the distinctive colouration they exhibit.  This is especially true for males as they often boast vibrant colours for display to attract a mate and defend territory.  Females and juveniles, and sometimes males in non-breeding plumage, can be difficult to identify.  It helps to know what group a bird belongs to as it greatly increases the likelihood of identifying it.

Yesterday I was paddling on Lake Ellison, a small lake near my home in Kelowna.  I photographed a small bird on the shoreline trying to get a drink of water.  Back home later, I attempted to determine its specific breed, and I wasn't sure if it was a sparrow or finch.  The dull brown markings gave me reason to think it was either a female or juvenile. This confounds identification as sometimes the young bird doesn't look like either of the adult sexs.

I started with sparrows and couldn't find any reasonable matches.  Then I noticed the beak - thick, strong, and conical - maybe it was a finch.  And so I altered my hunting parameters and looked at possible finch species and came up with two alternatives.  It was either a Cassin's finch or a Purple finch, probably juvenile.

Although both bird groups have a lot of similarities, one of the best features to consider is the bill.  Sparrows tend to have a conical bill that is not as strong or deep as the bill of a finch.  Finches often have a very pronounced conical-shaped bill that is almost shaped like an equilateral triangle from the side.  I have included some images below to show the difference.  I hope that helps.

Sparrows (left) and finches (right) - notice the difference in beaks.

It is not an absolute guarantee that all finch bills are larger than sparrow bills, but it is a good place to start if you are unsure.

Thanks for reading.

Eric Svendsen     www.ericspix.com