Palm Warbler

Setophaga palmarum

Palm Warblers get their name from the region where they spend winters. Nesting further north than most moth-eaters (genus Setophaga), summers find them in regions (mostly in Canada) dominated by boggy shrub lands surrounded by conifers. Such habitats are unfriendly to the palm trees for which they are named. Even in winter we find them often in marshy lowlands in habitats that seem better suited to sparrows.

In keeping with their low-to-the-ground reputation, their nests are usually placed on the ground below a small conifer, though they sometimes place the nest on a low branch about a foot from the ground.

Taxonomists call out two subspecies, diagnosed chiefly by coloration on the bellies of these birds in breeding plumage:

• S. p. palmarum breeds in Canada from southwestern Mackenzie Valley (NWT) east through northern Saskatchewan and Manitoba to northern Ontario, and south from central Alberta through central Saskatchewan and southern Manitoba to northern Minnesota, Wisconsin, and southern Ontario. They spend winters chiefly in the Caribbean Basin, with some occurring north to the southeastern United States, and some spend winters south along the eastern edge of the Yucatan Peninsula and Costa Rica.
• S. p. hypochrysea breeds further east, from eastern Ontario through central and southern Quebec to Labrador and Newfoundland, and south from New Brunswick and Nova Scotia, through northern New England to New York. They spend winters primarily on the Gulf Coast from Louisiana to Florida.

To date, my only meeting with this species has been on Isla Socorro in the Revillagigedo Islands, during a 2017 science expedition I was privileged to attend.