A Field Study of Wild Echidna Responses to Conspecific Odour

Mammalian olfactory cues play a crucial role in coordinating mating behaviour as they contain pertinent information on sex, reproductive status and receptivity to mating. Males of many species are particularly attentive to changes in female odour cues, as these can be used to find potential mates and monitor changes in reproductive condition. Such sensitivity is likely to be especially important for usually solitary or seasonally breeding individuals. We used remote scent trials in the field to examine if wild short-beaked echidnas are attracted to conspecific female odour. Our results are consistent with the hypothesis that male echidnas use olfactory cues during the breeding season to locate females: Echidnas were only observed investigating female odour samples and not empty camera trap stations, more echidnas (including known individual males) were attracted to female odours during the breeding season, than during the non-breeding season and we noted olfactory behaviours such as sniffing and tongue-flicking at the odour source. Male echidnas increase their mating opportunities by engaging in scramble competition and being sensitive to volatile and non-volatile female odour components, allowing them to locate potential mates and minimise search costs. Consequently, male ability to locate females may be sexually selected, but further bioassays, along with genetic information, is needed to investigate this further.