Tapir vocalizations: A comparison with equines and other perissodactyls

The perissodactyls (odd-toed ungulates) comprised of equines, rhinos, and tapirs have vocalizations during which the frequency spectra can change, in contrast to the artiodactyls (even-toed ungulates), comprised of cows, sheep, deer, etc., whose vocalizations are primarily tonals. This suggests that a simple vocal expression by perissodactyls may be possible, and a recent study of horse whinnies under different conditions indicates that this may be the case. The vocalizations of tapirs, perhaps the least studied members of this group, are compared to those of equines and rhinos.