The white-tailed sparrow comes in two models: white-striped and tan-striped. The first model, seen here, has black and white head stripes, whereas the other model has brown and tan head stripes. Technically, this is known as plumage polymorphism — but I only talk that way when I'm trying to be uppity.
Click to enlarge.
Now here is where things get interesting. The white-striped members of this species defend their territory more aggressively than their tan-striped brothers and sisters. On the other hand, the tan-striped individuals take better care of their young. So, if you were a baby white-throated sparrow, which parental style would better ensure your survival?
Don't try answering, because it's a trick question. White-striped individuals almost always mate with tan-striped individuals, and vice versa. So, as a baby sparrow, you always benefit from both parental styles.
White-throated sparrows tend to stay near the ground, but I tricked this one into posing at eye level by placing some sunflowers seeds on a fence post.
For more information on the white-throated sparrow:
- Smithsonian Migratory Bird Center
- Cornell Lab of Ornithology