Chemical signals of age, sex and identity in black rhinoceros

► We tested the function of olfactory signals in rhinoceros dung and urine. ► The duration and frequency of sniffing events varied between olfactory signals. ► Donor age, sex and identify was discriminated from faecal samples. ► Both urine and dung function as signals and faecal signals persist as dung decays. ► Dung and urine chemosignals may be important to rhinoceros social organization.