Identifying Bats
Identifying captured bats can be more difficult than finding them. The first step is to decide on whether your captured bat is a male or female. In most bats, this decision is easy because the penises of bats are conspicuous. Also, on many bats, worn areas around the nipples make it easy to recognize the adult females.
Another question, is the age of the bat. This is quite difficult, as young bats grow rapidly. Fur color can provide a clue though, in many bats, the young have dark and blackish fur as compared to the lighter colored fur in adults. Another indicator is found at the finger joints. Adult bats have knobby finger joints, and young bats have smooth ones. The adult ones are knobby because bone formation is complete. The smooth ones of the young reflect incomplete growth.
After detecting the gender and age, the next step is to identify the species. This depends on the variety of bats living where it was caught. Identifying a bat in Hawaii is easy because there is only one species that lives there. But, compare this to the more than 50 species in many parts of Africa, and the more than 100 in some countries in South and Central America.
A first step is to identify which of the 19 living families it belongs to. Sometimes the family name will provide a clue, for example, the New World disk-winged Bats have distinctive adhesive disks on their wrists and ankles and live only in the New World. The Old World Disk-Winged Bats, also have this but occur only in the Old World, only in Madagascar. Usually the details of the bats appearance are used to decide its family affiliations.
Many features may be used to distinguish between species of bats. Wherever possible, they will rely on obvious objective features like size, number of teeth, and color.