Believe this is a hermit thrush but never had the opportunity to shoot it in good light with my macro lens before it flew off.
Chromatic aberration (CA): Abnormal coloring along contrasty edges, especially backlit subjects. On many of the better photographic equipment review sites, such as my favorite, DPReview.com, chromatic abberation is highlighted during each lens's in-depth review. Manufacturers will apply special lens coatings to reduce CA because it can ruin an otherwise great photo if it becomes too prevalent. Chromatic abberation occurs because light enterning the lens at different angles bends at different rates as it passes through the lens system (typically multiple lenses in one casing) en route to the imaging sensor. While I love my Nikon 105mm macro lens, it has pretty bad CA. I don't see it much at all in macro photography, but, shooting a bird in a tree or on a pole, where the bird is backlit or has gray sky behind it, really shows the CA is pretty poorly controlled. Special lens coatings also add to the coast of the lens (glass.) So this is another area of trade-off in pricing if this is something important to you. CA tends to show itself in two primary highlights; green and purple. In many cases, good photo processing software can remove or greatly reduce CA, but it never really replaces the CA with the real colors. Replacement tends to make those areas appear more gray than any other color.
Believe this is a hermit thrush but never had the opportunity to shoot it in good light with my macro lens before it flew off.