Mom’s home pecking
| (Elizabeth Pols illustration) |
The shape of a bird’s beak may reflect what’s been for dinner in the habitat where it evolved: chunky for crushing seeds, slender for catching insects, etc. As surely as tubas differ from flutes, differently shaped beaks produce different song. And song is a key element in avian courtship and mating. In research published in the journal Nature this winter, UMass biologist Jeffrey Podos suggests that this sequence – from different foods to different beaks to different voices – may have figured in the evolution of Galapagos Islands finches. “We think that 4 million years ago there was one ancestral species,” Podos told the Springfield Union-News. Now the tough-beaked lowland finches are quite distinct from the smaller-beaked forest-dwellers. A report in academicpress.com says that Podos’s study “is one of the few, if not the only” showing how habitat can change mating signals.
