Biology 342 Fall 2014
How do meerkat vocalizations change with a predator's location?
Meerkats primarily communicate with members of their own species through vocalizations. Although meerkat vocalizations are on average 0.1 seconds long, these vocalizations are dependent upon individual bark frequency, as well as their environment and situation. For instance, meerkats bark rapidly to warn other individuals of the presence of a predator, and they bark less frequently when they are lost. Bark frequency within individuals is not highly variable, but bark frequency across individuals is highly variable as seen in the figure to the right (Townsend, 2014). Graph a) shows the spectrogram of three barks from the same individual, while b) shows the spectrogram for one bark for three different individuals. In both figures frequency is on the Y axis.
Meerkat vocalization is additionally affected by the type of predator as shown in the figure below. Research has found that when meerkats vocalize to warn other foraging individuals of a terrestrial predator, like a snake, they emit barks with a higher frequency. In contrast, in the presence of an aerial predator, such as a hawk, their barks have a lower frequency (Townsend 2014). The meerkat bark can be broken down into two sections F1 and F2. In F1 compared to F2, there is a greater change in frequency between barks in response to a terrestrial predator versus an aerial predator. This is shown in the figure below. Graph a) shows F1 and graph b) shows F2 in response to terrestrial and aerial threats. In both graphs frequency is on the Y axis.
12) Figure courtesy of Townsend, 2014