The vocal repertoire in Northern white rhinoceros Ceratotherium simum cottoni as recorded in the last surviving herd
The Northern White Rhinoceros Ceratotherium simum cottoni is a subspecies of the White Rhino that is almost extinct in the wild. We studied the last reproducing herd kept in Zoo Dvur Kralove to describe its vocal repertoire. The calls produced by eight individuals were recorded and analysed as concerned both sound properties and behavioural contexts […]
Interference risk and the function of dynamic shifts in calling in the gray treefrog (Hyla versicolor)
Male gray treefrogs call to attract females under challenging acoustic conditions. At higher chorus densities, there is considerable background noise and a good chance that a male’s calls will often be overlapped by calls of other individuals. Call overlap may reduce the probability of mating because females prefer calls with internal pulse structure that is […]
Acoustic convergence between two nocturnal burrowing seabirds- experiments with a penguin Eudyptuh minor and a shearwater Puffinus tenuirostris
The evolution of acoustic signals is influenced by environmental constraints. We studied two sympatric but unrelated seabirds: the Little Penguin Eudyptula minor and Short-tailed Shearwater Puffinus tenuirostris, to examine the degree to which similarities in their ecology had led to convergence in their calls. Both species nest in burrows in Southern Australia and, at night, […]
Acoustic cues to size and quality in the vocalizations of male North American bison, Bison bison
Source-filter theory provides a framework to interpret the acoustic structure of vertebrate vocalizations in relation to biophysical production, and it predicts that specific acoustic parameters can encode information about callers. Because formant frequencies are determined by vocal tract dimensions, with longer vocal tracts producing lower formants, they can be reliable indicators of body size, as […]