Using the bolus size of our collected dung samples, we classified
the detected individuals into three age classes in accordance
with Sukumar (1992): (1) calves or juveniles = 0–5 years; (2) subadults
= 5–15 years; and, (3) adults >15 years. Our bolus size
distribution clustered into three easily distinguishable groups,
which in turn were taken to represent each of the three predefined
age classes (Fig. 2a). The resulting cut-off points between
the age classes (10 cm between juveniles and sub-adults and 15 cm
between sub-adults and adults) were in good concordance to bolus