Southern Yellow Bat: Lasiurus Ega

Photo of a deceased southern yellow bat

The southern yellow bat is a stunning, palm-dwelling bat whose range was thought to stretch only as far north as Corpus Christi, Texas. This bat is native to north, central, and south America with a range between the Rio Grande river and northern Texas.

They mimic characteristics of the northern yellow bat, but they are much smaller in size and look more delicate. In contrast to the clumsier, sleeker, blonde northern yellow pups, the southern yellow pups often look more woolly, or olive colored.

Learn More: Different Bat Species 

Physical Description Of The Southern Yellow Bat

The southern yellow bat is a medium-sized bat with a dull, sooty yellow fur. Its tail membrane is fully furred and on its shoulders and wrists, it lacks distinctive white markings.

This bat species has a 43-49 mm forearm length and weighs 11-14 g.

The southern yellow bat is most easily mistaken for the northern yellow bat in south-eastern Texas, where the two species occur together. However, with a forearm length of 49 mm or less, the southern yellow bat is smaller compared to 51 mm or more for the northern species. 1Go To Source -“Southern Yellow Bat (Lasiurus Ega)”

Souther Yellow Bat Habitat

The Southern Yellow Bat primarily roosts year-round under the dead fronds of palm trees.

The species is know to live around natural palm groves along the Rio Grande near Brownsville, TX, but can be seen as far north as Corpus Christi, TX where it uses ornamental palms to roost.

Range Of The Southern Yellow Bat Species

This neotropical species of souther yellow bats appear in southern California, southern Arizona, southern Texas and several countries south of the U.S. border. The range has been expanded to the north by two recent reports from Comal and Fayette counties. The range of this tiny yellow bat extends to Uruguay and northeastern Argentina southwards east of the Andes. 2Go To Source -“SOUTHERN YELLOW BAT Dasypterus ega (Gervais 1856)”

Southern Yellow Bat Diet

A nocturnal insectivore is the southern yellow bat. They feed on small to medium-sized flying insects for one to two hours after sunset.

They eat close to their roost, and go no further than they need for water.

Conservation Of The Southern yellow Bat

A fungal disease called white-nose syndrome” is now endangering all North American bats. Since 2007, this disease has destroyed southern yellow bat populations at hibernation sites. TWhite-nose syndrome is a fungus that thrives in cool/humid conditions (same conditions bats tend to live).

The fungus grows on the bodies of hibernating bats, and in some cases invades them, and tends to result in hibernation disruption, causing a weakening loss of substantial metabolic resources and mass deaths. Mortality rates were as high as 90 percent at some hibernation sites. 3Go To Source -“Lasiurus ega southern yellow bat”




  1. Natural Science Research Laboratory. “A Species Account of the Southern Yellow Bat (Dasypterus Ega) | Mammals of Texas | Natural Science Research Laboratory | TTU.” Texas Tech University, Accessed 10 Dec. 2020.
  2. TPW Foundation. “Southern Yellow Bat (Lasiurus Ega).” Texas Parks And Wildlife, Accessed 10 Dec. 2020.
  3. Fahey, B. 1999. “Lasiurus ega” (On-line), Animal Diversity Web. Accessed December 10, 2020 at