DIVERGED SWALLOWS
When I was a boy living in farmland in Lancaster County, Pennsylvania, I was familiar with barn swallows nesting in open-topped, mud-pellet cradles they built themselves on the sides of support beams in a barn. And when I entered the barn, parent swallows would dive at me and call harshly to drive me away from their eggs or young in those nurseries. Swallows have always fascinated me. Their swift, swooping flight is entertaining. I have seen six different kinds in the eastern United States over the years, including barn swallows, cliff swallows, bank swallows, rough-winged swallows, purple martins and tree swallows. And, having diverged from a common ancestor, all swallows, world-wide, have traits in common with each other, including those species in the eastern United States. They are all built much alike, with streamlined bodies, long, narrow wings and small beaks, with large gapes for ensnaring flyin...