CHAPTER 5 EXAMINING BATS 50 Figure 5.1 The features of a bat. Figure 5.2 Sexual development in the male. a Juvenile b Adult 4th digit 5th digit Metacarpals Calcar Tail Interfemoral membrane Post-calcarial lobe Foot Phalanges Tragus Humerus Antebrachial membrane Forearm (radius) Thumb 2nd digit 3rd digit
5.2 SEXING AND AGEING 51 Milk maybe extruded from the nipple by gentle finger pressure on the base of the nipple. After lactation, the nipples retain (except in the case of Daubenton’s bats) their enlarged, often darker, appearance and inmost species of bat, as in other mammals, such nipples show that the bat has given birth. Bats that have had several young tend to have large nipples, but distinguishing between primiparous (having given birth once) and nulliparous females outside the breeding season often requires careful examination with the aid of a lens. The nipples of nulliparous females are rudimentary and often have tufts of hair on them. The nipples of parous animals show the expected characteristics of previous suckling they are dark and cornified, either with no hair or with short, wavy hair.