For example, if playbacks of feeding syllables influence rat feeding behavior and playbacks of probabilistically deviant syllables do not influence it, this would suggest that feeding syllables have functional meaning as an emotional contagion [31], [32].
The aim of the present study was to test the communicative value of 50-kHz calls by measuring overt and calling behavior during playback of such calls.
During the entire experiment, the owner was listening to music through headphones to prevent him/her from hearing the playbacks and influencing the behavior of the dog unintentionally.
In experiment 1 (Figure S1g), there were a significant signal and signal x time interaction effects – kangaroos showed little alteration to these behaviors after playback of the hiss (even returning to eating) or raven call.
Burgdorf et al. [32] found that rats show instrumental behavior to receive playback of 50-kHz calls, whereas Endres et al. [59] did not find overt behavioral effects of 50-kHz playback.
With respect to male USV, it was shown that devocalization of male rats resulted in a reduction of female proceptive behavior [61], and playback of 50-kHz calls restored proceptive behavior in oestrus females [23], [25], [27].
The few studies, which were conducted in a non-sexual context, however, obtained very weak or no playback-induced effects on overt behavior.
During the first minute (prior to playback), the only significant difference between behaviors across the experiments was greater relaxing behavior in minute 1 (PC4; relaxed) for experiment 2. This result does not reflect any biological meaningful significance; rather it represents variability in the baseline data.
However, laboratory studies [ 1, 27] revealed that unlike other rodent species, spiny mice do not alter behavior when exposed to playback of recorded owl calls.
