Signalling adjustments to direct and indirect environmental effects on signal perception in meerkats

The efficiency of communication between animals is determined by the perception range of signals. With changes in the environment, signal transmission between a sender and a receiver can be affected both directly, where the signal’s propagation quality itself is affected, and indirectly, where for example the spacing between signaller and receiver is impacted. Here we investigated how meerkats (Suricata suricatta) in the Kalahari Desert adjust to these challenges in the context of maintaining group cohesion through contact calls. We found that meerkats changed their calling rate when signal transmission was affected indirectly due to increased dispersion of group members as during a drought, but not under typical wet conditions, when signal transmission was directly affected due to higher vegetation density. Instead under these wetter conditions, meerkats remained within proximity to each other. Overall, both direct and indirect environmental effects on signal perception resulted in an ...