Habitat characteristics influence the efficacy of animal communication, and population differences insignal structure due to habitat variation are well known for sound and colour signals. However, thisvariation in signal structure has not been reported for motion-based signals. Here we tested the motion-based signalling displays of two populations of an Australian agamid lizard, Amphibolurus muricatus, inthe context of their respective habitats. We employed a novel approach that calculates the distribution ofmotion speeds of lizard signals and environmental noise independently, before computing the differencein these distributions to obtain a measure of signalenoise contrast. Our results revealed variation insignal structure between the two populations and support the hypothesis that this variation can beexplained by differences in the signalling environment. Signals from both populations showed similarcontrast values at their respective habitats, but differed significantly when considered in the habitats ofthe allopatric population. These results are consistent with the hypothesis that habitat structure affectssignal efficacy and causes population differences in motion signalling behaviour as a consequence of adaptations to enhance efficacy.
Ramos JA, Peters RA (2017) Habitat dependent variation in motion signal structure between allopatric populations of lizards. Animal Behaviour 126, 69-78
Figure | Differences in signal structure between populations. (a) Mean ± SE bout and tail flick durations for both lizard populations. (b) Mean ± SE tail flick to bout ratio for both
lizard populations. (c) Average kernel density functions for both lizard populations.