Not All Migratory Birds Are “Neotropical”

By Robert Ross

I was still a little boy when I realized that my grandparents were gone from Pennsylvania for the winter. Where did they go? Like many of us still do when retired: to Florida or another warm winter place. And likewise, the reverse is also true of many Florida retirees who wander north during summers. My aunt and uncle did so because, among other reasons, they loved Pennsylvania sweet corn in season and abundance here. This reason matches exactly the major theory why birds from the tropics evolved to migrate north to breed in the Temperate Region: an abundance (and therefore less competition) of food (forest insects) for successfully raising young.

A year ago I wrote about neotropical migrants that we suddenly hear and see in our yards and forests come Spring in Pennsylvania. These birds spend their winters in tropical America (southern Mexico to South America) then migrate north to nest and raise their young in temperate and arctic North America. However, there is another group of birds that are still migratory, but stay largely north of Mexico and the Caribbean: nearctic migrants. The same theory explains their migration: explosive food supplies for a brief part of the summer as far north as the arctic tundra. These are the birds that also winter in big numbers in places like Florida. For those who travel to or winter in Florida, you will see these birds in your yards and forests there as wintering birds (like many of us “snowbirds”), then the same birds back up here in Pennsylvania as spring/summer breeding birds. Examples among insectivorous warblers include pine, palm, yellow-throated, and yellow-rumped warblers (see photos). These songbirds are an occasional treat to hear and see in my yard in Pennsylvania. But in recent winter trips to Florida I found them to be common “yard birds” there. They just don’t fly so far between summer and winter homes as do the neotropicals!

And what about our most ubiquitous Pennsylvania songbird, the American robin (with a namesake scientific name Turdus migratorius)? On rainy days in Florida I found them foraging in many yards by the dozens. Of course there are many variations of this nearctic migration pattern. The palm warbler mentioned above actually overflies us in Pennsylvania, stopping in migration here only to feed/refuel, before reaching subarctic breeding or subtropical wintering locales.

So the next time you “head south for the winter,” remember that birds have been doing this for way longer than humans have, and perhaps for similar reasons. Go into our forests and enjoy them while you can. Seasons are short. And tip your hat to a brook trout, wood frog, or fisher. May the Forest be with you!

Photos by the author