Convergences and Divergences in Communication and Social-Organization of Desert Rodents

Abstract

Has behaviour of desert rodents evolved to show convergences in the same way as morphological and physiological traits? To answer this question, I compared social behaviour and communication of rodents from deserts in North America, Africa, Eurasia and Australia, Most desert rodents, except those from Australia, sandbathe and footdrum as primary modes of communication. In contrast, social behaviour in desert rodents has evolved across a wide spectrum of sociality. The most highly evolved social organisation in mammals occurs in two species of eusocial mole-rats from arid deserts in Africa, Asian gerbils live in stable family groups, and jerboas in northern Africa may be socially tolerant. The heteromyid rodents from North America, however, live alone in a social structure maintained by neighbour recognition. These communication convergences and social divergences may be explained by the evolutionary history of the rodents and by contrasts in resources, predation and climate. Mole-rats must cooperate to harvest dispersed underground tubers in arid environments. Varied diets and cold climates possibly selected for group living in the highly social gerbils. The long and successful evolution of heteromyid rodents as solitary granivores may explain why they have not taken the next step in social evolution.