FEMALE CHOICE INCREASES FERTILIZATION SUCCESS IN THE AUSTRALIAN FROG, UPEROLEIA-LAEVIGATA

Males of the Australian frog, Uperoleia laevigata (formerly referred to as U. rugosa), compete intensively for opportunities to attract and mate with females, but it is active female choice that determines which of these males are successful. Females select mates that are about 70% of their own body weight, choosing on the basis of the males' calls. Females offered a choice of two synthetic calls approached the call with a dominant frequency equivalent to a male 70% of their body weight in preference to calls equivalent to heavier or lighter males. Artificial pairing of males and females showed that this choice is adaptive as only females mating with males that were 64-80% of their body weight had most of their clutch fertilized. Hcavier males hamper oviposition and lighter males may have insufficient sperm to fertilize the whole clutch. © 1990.