MALE RED-BACKED SALAMANDERS CAN DETERMINE THE REPRODUCTIVE STATUS OF CONSPECIFIC FEMALES THROUGH VOLATILE CHEMICAL SIGNALS

Abstract

Previous research suggests that female red-backed salamanders (Plethodon cinereus )i n Virginia court biennially whereas males court annually. Therefore, males may face a choice to court either gravid or nongravid females. Because gravid females represent an immediate insemination opportunity (whereas nongravid females do not), male red-backed salamanders may be under selection to be able to distinguish the reproductive status of conspecific females. We conducted an experiment to determine if males could discriminate between gravid and nongravid conspecific females through volatile chemical signals. Focal males were allowed to establish territories in testing arenas for 5 d and then were exposed to three treatments in a randomized order: volatile chemical signals from gravid females, nongravid females, and a control (blank filter paper). Randomization tests revealed that focal males exhibited significantly more aggressive behavior when they were exposed to volatile chemical signals from nongravid females than when they were exposed to those from gravid females and the control. We infer that male red-backed salamanders can determine the reproductive status of conspecific females through volatile chemical signals, which may influence their social associations.