1 1/2-1 7/8" (38-48 mm). Large, long-winged and long-tailed. Above, warm brown FW has median row of bright, glassy, gold spots, 1 spot beyond the row, and minute dots near tip. Below, FW similar, paler toward tip; HW mahogany, frosted with whitish scales, and large, crisp whitish patch in lower disk with white bar below patch near tail base.
White-striped Longtail has paler yellow spots above, white stripe on HW below.
Spring in Arizona, autumn in Texas.
Tropical forest and subtropical scrub.
SE. Arizona, S. Texas to Ecuador.
The Zilpa Longtail is not a year-round resident north of Mexico, but wanders infrequently to Arizona and Texas.