28-3-2017 CARARA NAT PARK, COSTA RICA - NORTHERN GHOST BAT (Diclidurus albus)

The northern ghost bat can be distinguished from other members of its genus by the presence of a vestigial thumb with a near-absent claw. Amongst the northern ghost bat population, sexual dimorphism is present. Specifically, males tend to be slightly larger in size when compared to females. Diclidurus albus is intermediate in weight relative to other members of the family Emballonuridae.

The northern ghost bat has a widely shaped clavicle bone, with large areas of attachment for the pectoralis muscle. It also has a large glandular structure on its uropatagium. The functional significance of this glandular structure is thought to be analogous to that of wing sacs in other emballonurids. When breeding, the wing sacs of other emballonurids become enlarged to attract females.

The penis of the northern ghost bat does not employ a baculum, but rather, is composed of four cartilaginous bodies. It is about 5.5 mm long and 3.1 mm in diameter. The glans penis is white in color, and the prepuce is encased in a layer of short, fine hair. The testes are spindle-like in shape, symmetrical, and enclosed in a black tunica. In females, the ovaries are ovoid in shape and are roughly 2.8 mm long and 0.8 mm in diameter.