Vocalisations of the Chillingham Cattle

Chillingham cattle live, free of predation and subject to minimal human interference, in a park in northern England. Bulls live in pairs or trios in shared home ranges. Breeding is not seasonal. Sonagraphic analysis of vocalisations made by bulls enabled the two major components-calls and lows-of their vocal repertoire to be described. Lows were of two categories: 'Type 1' with a main peak of energy at 175 Hz and one harmonic, and 'Type 2' with a main peak at 220 Hz, and seven harmonics. On many occasions, a low of Type 1 changed to Type 2 without interruption. A preponderance of Type 2 in the repertoire of an individual bull is probably associated with high social status. Each call comprised a series of hoots; mean number per call might also serve to distinguish individuals. Bulls vocalised in response to the vocalisations of other bulls, particularly to those of their home range partners. Generally, the more hoots in a preceding call, the more hoots in the response. The call of the Chillingham bulls is unlike any of the vocalisations of races of Bos taurus described in the literature. Its ontogeny probably involves practice and competition with peers, on the part of juvenile bulls. The reason why other Bovini are relatively silent, or possess as adults simple calls developed from those of calves, may be due to the lack of opportunity for juveniles to practise their vocalisations. This might be due to predation pressure or, possibly, in seasonal breeding species, to aggression from mature males.