The entrainment of breathing rhythm to stride frequency in the dik-dik antelope (Rhynchotragus kirki) with observations on the thermoregulatory consequences

Abstract

1. Three adult dik-dik antelopes with an average weight of 4.5 kg were used to investigate the rate of oxygen consumption (V̇O2) during exercise and the entrainment of respiratory rate with stride frequencies at running velocities between 2–11 km/hr. 2. The results of V̇O2 and the metabolic cost of horizontal locomotion were found to agree with what would be expected of an animal of this size. 3. Respiratory frequencies recorded during the most strenuous exercise were approximately 50% below the value observed when dik-diks are exposed to an ambient temperature (Ta) of 42°C. 4. Respiratory evaporative heat loss was estimated to account for only 4% of the total heat production during exercise. 5. Respiratory frequencies were found to be entrained quite strongly to stride frequencies. The thermoregulatory consequences of this entrainment is discussed.