Unrelated cousins

We have grosbeaks: similarly looking, heavy-billed, seed- and insect-eating birds that have been lumped together as a group for over three centuries. They are, what is referred to as a form taxon, a group based, not upon their biology, but merely their appearances and behaviours.

In the past week, I have watched two grosbeaks: the Black-headed Grosbeak, which is a cardinal grosbeak, and the Evening Grosbeak, which is a grosbeak finch. These two are only distantly related. When seen in the pictures, they are clearly different, but when spotted in the field, I thought they were the same.

The Black-headed Grosbeak is a seasonal bird that is here in small numbers in the warm months. Its heavy bill is obvious.

Also relatively uncommon, the Evening Grosbeak might be seen at any time of the year.

Here the Evening Grosbeak poses for a contemplative portrait.