Thom Smith | Naturewatch: Female birds attracted to 'sharp-dressed' males


Q: Today I was watching a male goldfinch and a female goldfinch on my feeder. I thought: "He is snazzy. I can appreciate that the female might be attracted to him."

Then I had an ominous thought: "The attractive male bird might — because of his outstanding coloration and designs — be more readily noticed by predators. The male bird might draw a predator's attention away from the less colorful and noticeable female? Or, the male, being so outstanding looking, might, due to his looks, scare off predators?"

— Lenny, Pittsfield, Mass.

A: You are partially correct, the bright colors of a male do better attract the attention of predators, but as Charles Darwin theorized, that isn't all. He concluded that sexual dichromatism or color differences between sexes in birds may have largely developed from female preference for bright colors.

It has long been noted that females of species that are exposed to predators while incubating tend to have dull colors, though both sexes may be brightly colored in species that nest in tree hollows because the females are less visible to predators. And many ground nesters may be similarly colored to blend in with surroundings. Because females are often in short supply, males must compete for the favor of passing on their genes and apparently the healthier are often more brightly colored. We don't necessarily see all these differences because diurnal birds in general see a greater spectrum of colors than do we humans.

Q: Hanging from our bird feeder was a chunky little animal, brown on top and white underneath. It had black protruding eyes. I looked it up on the Internet and the closest I could find was a dormouse, but they are not found on this continent. Any idea?

— Donna, Otis, Mass.

A: This is an easy one. It was (and probably still is) a flying squirrel. They are common, but rarely seen because they are among our most nocturnal mammals and are mostly active at night.

I once raised an orphan flying squirrel and it often slept in my shirt pocket during the daytime, but at night raised all sorts of commotion. I finally released it simply by taking it outside one night and letting it scamper away. At the time I lived across the road from Pleasant Valley Sanctuary in Lenox, where it had plenty of mature trees in which to find a hole to live in or it could have stayed in the trees in our yard if it preferred.

I can understand how these "cute" little squirrels could be confused with a dormouse as both are nocturnal and are largely, but not exclusively arboreal, well adapted to climbing, and chunky in appearance. The dormouse is mostly European, though.

Our flying squirrels should more accurately be named gliding squirrels as they do not fly, but glide. Climbing up a tree, they can throw themselves into the air and glide downward some distance, correcting their direction somewhat by their flat tails used rudder-like.

Years ago, a family of flying squirrels lived in a large elm on South Street in Pittsfield, directly in front of the lovely old brick apartment building on the corner of South and East streets. It would visit a hanging bird feeder on the third (if I recall correctly) floor. And, I am sure that if there were no seed-filled feeder there, no one would have known of its presence.




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