Gray Sac-winged Bat - Appearance

Appearance

It is known as the gray-sac winged bat first because of the sacs located between the wrist and the neck on the membrane of the wing, which is far more prominent and developed in males than in females. This sac is a defining feature: in this bat, the sac is in the center of the antebrachial membrane, while in others it is not centrally located. There have been reports that the inside of this sac is white, but others have stated that it varies in color and texture depending on the age of the bat and the season. Whichever the case, the sac has a proximal opening. The second reason this bat is known as the gray sac- winged bat is because of its coloring, which can range from the gray color it is known for to a rich brown; despite the differences, all varieties have white trim. It has darker colored fur on its back (dorsal) and lighter covered fur on its front (ventral).

The common feature among the Emballonuridae family is the sheath tail, meaning that there is a membrane that stretches from one of the bat’s ankles to its other, and the majority of the tail is covered by the membrane, with only the tip protruding. Its wing attaches to its ankle and its tail protrudes approximately 6mm away from its body. The average weight of a male is 6.1 g, and for the non-pregnant female the average weight is 7.1 g; their average body length is 66.6 mm. Unlike in many other bat species, there is no dorsal furrow between the nares, and the rostrum has been described as “inflated.” The ears are rounded and the thumb is about 5 mm long (considered long) and thin.