Latrines as Potential Communication Centres in Short-Beaked Echidnas

Abstract

Localised defecation sites (‘latrines’) are an important method of intraspecific olfactory communication in mammals. As efficient, low-cost methods of exchanging information, latrines might be especially important for solitary or widely distributed species, or those with low metabolic rates or low-energy diets. Latrines can be difficult to find and closely monitor, but information on their spatial distribution and patterns of use can provide useful insights into their possible functions. We used geographic mapping and remote cameras to describe spatial, temporal and behavioural patterns in latrine use in a normally solitary monotreme, the short-beaked echidna ( Tachyglossus aculeatus ; ‘echidna’). We found 64 echidna latrines, usually under logs in scrub habitat and in areas of intermediate (rather than low or high) areas of overlap between resident echidna home ranges. Latrines were most often visited through July–November, and fresh scats were found between August and February. When visiting latrines, echidnas showed olfactory behaviours such as scanning and nose-poking at the soil, suggesting latrines are not used purely for defecation and likely perform a role in communication. We suggest that latrines play a role in signalling habitat use, particularly among females, whereas males might use latrines to monitor the location and activities of potential mates and competitors.