Age estimation of pteropodid bats (Megachiroptera) from hard tissue parameters

Abstract

This investigation employed undecalcified thin (10 µm) and thick (100 µm) mid-root sections of surgically removed canine teeth, and thick sections of diaphyseal fore- and hind-limb bones from 14 fruit bats (Pteropus alecto and R poliocephalus) of known age, to attempt to establish a relationship between the chronological age of these animals and changes in the cross-sectional morphology of the hard tissues. Growth layers in bone, dentine and cementum were clearly visible in cross sections when viewed by Nomarski interference microscopy. The number of growth layers in the periosteal region of long bones and in dentine varied widely within a given section, making it impossible to estimate age from these tissues. Dental cementum most reliably reflected the age of fruit bats, with both growth layers and the radial thickness of cementum showing significant correlations with age (P<0.05). Linear regression was used to formulate equations for estimating age. The simplicity of this technique may provide investigators with a useful method for estimating the age of pteropodid fruit bats.