About Dasypterus ega (Gervais, 1856)
Dasypterus ega, commonly known as the southern yellow bat, is a small bat named for the yellow fur that covers its body. On average, females are larger than males, with a forearm length that averages 4% (1.83 mm) greater than that of males. Southern yellow bats range from the southwestern United States down to northern Argentina and Uruguay. The southernmost known record of the species is from Buenos Aires province, Argentina, located at 40° S. They live in wooded areas including forests, foliage, and palms. They roost in trees and vegetation, and will occasionally occupy sites that resemble large dead leaves, such as dried corn stalks and thatched roofing. In Texas, their preferred roosting sites are the frond "skirts" of both wild and ornamental palm trees, such as Sabal mexicana and Washingtonia robusta. These frond skirts are accumulations of dead fronds attached to the tree trunk, which create the dark habitat this species favors. Palms also host the insects that southern yellow bats feed on. This species, previously referred to as Lasiurus ega, is monoestrous, meaning it has only one breeding cycle per year. Copulation occurs before the end of hibernation, but females delay ovulation and store sperm for six months, with fertilization taking place later. Following mating in July, which is early winter, all reproductive organs involute and remain inactive until the following April, which is autumn. Gestation lasts 3 to 3.5 months, and young are born in late seasonal time.
