The name Semipalmated, as in Semipalmated Plover Charadrius semipalmatus derives from the latin semipalmatus meaning half (semi) palm (palma) referring to the partial webbing between their toes, as can be seen in this photo.
We see a large influx of Yellow-rumped Warblers during the fall months as they move through the Delaware Valley and Mid-Atlantic region. They are without a doubt the most numerous fall migrant warbler. While the majority of our wood-warblers head to tropical climates for the winter, many Yellow-rumps overwintering in our area.
They are often found actively foraging in flocks feeding on insects and small berries that have a high fat content.
Two of these plants are amongst their favourite foods, Bayberry or Wax Myrtle, hence the name of the Eastern subspecies, "Myrtle" Warbler, and Poison Ivy, pictured here. The berries of both these plants are timed to ripen when the 'butter butts' move through, giving the birds the fuel they need to sustain them through the colder winter months.