No evidence for multimodal body mass distributions and body mass-related capture order in wild-caught Damaraland mole-rats

Abstract

Division of labour among workers is a universal property of eusocial insect societies. For Damaraland mole-rats (Fukomys damarensis), a eusocial mammal, it was proposed that workers can be divided into morphologically distinct (in terms of body mass) subcastes of frequent and infrequent workers. Here we investigate, by using capture data from a large number of colonies of Damaraland mole-rats, if body mass is multimodally distributed, which may be indicative of worker subcastes and, further, if there is a relationship between body mass and capture order, which may be indicative of morphological specialization for colony defence. Our analysis reveals unimodal body mass distributions for both sexes. Further, there is no evidence for body mass-related differences between individuals in the capture order. These data suggest that body mass is not an indicator of behavioural specialization in Damaraland mole-rats.