Tree swallow

[ TACHYCINETA BICOLOR ]

Not so long ago, people believed that when swallows disappeared in the fall they dove into ponds and spent the winter sleeping in mud. We now know that they fly to Central America for the winter, but their return each spring is just as magical. While a few individuals show up in February, it’s mid-March when swallows suddenly start arriving by the thousands. They push north earlier than most species because the tree cavities where they nest are a scarce commodity and it’s a hard fight (sometimes to the death) to stake a claim to one of these precious holes. Once a pair of tree swallows finds a home, they’ll defend it and wait until the arrival of favorable weather, a month or two later,

to begin nesting.

NATURAL HISTORY

Tree swallows are unique among the world’s 74 species because they eat berries and seeds in addition to insects. They have the unusual ability to digest the wax that protects many berries, which provide them with emergency rations whenever insects are in short supply.

KEY CHARACTERISTICS

Tree swallows have long, swept-back wings and a fast, darting flight pattern; they are sparkling metallic blue above and as white as a starched shirt below. To appreciate one at close range, visit

a local marsh or lake.