Acoustically different contact calls of mother and young goitred gazelle are equally individualized: is this a common relationship in ruminants?

Relationships between individualization and the acoustics of contact calls in ungulate mother and young are different between taxa. We compared the acoustic variables and individuality of adult female and neonate goitred gazelles Gazella subgutturosa. Discriminant function analysis based on six acoustic variables of nasal (closed-mouth) contact calls similarly accurately classified calls to neonate and adult individuals in spite of the prominent differences in the acoustic resonances (formants) and the mean fundamental frequency of their calls. In addition, we found prominent differences in duration, mean fundamental frequency and frequencies of the first four formants between nasal and oral (open-mouth) contact calls within and between adult and neonate age-classes. We discuss the effects on the acoustics of call production mode (oral versus nasal) and the relationship of acoustic differences and individuality in mother and young contact calls across species of ruminants (Bovidae and Cervidae).