Competition, courtship and control: Breeding strategies of female platypuses (Ornithorhynchus anatinus) in captivity (#267)
Courtship behaviour is important in sexual selection by allowing animals to select or reject mates based on mate “quality”. Opportunities to study these behaviours are often limited and they have never been studied in wild platypuses (Ornithorhynchus anatinus) due to their cryptic nature. We studied breeding pairs and trios of platypuses over seven years in a successful captive breeding program at Healesville Sanctuary, Victoria, to describe and quantify breeding interactions, to determine which sex controlled courtship behaviours and to investigate whether females used evasive strategies to avoid mating. Behaviour, including non-contact and contact courtship, mating and avoidance, was recorded daily with infrared cameras and footage analysed for these activities. Breeding behaviours occurred over 41.0 ± 6.6 days, with females behaviourally receptive for 29.6 ± 5.1 days. Females demonstrated evasiveness and controlled the duration of breeding behaviour in 79% of encounters. We also describe a new, antecedent courtship behaviour, with females reducing or changing their activity in the pre-breeding phase while they were non-receptive to minimise contact with males, most likely to avoid injury from coercion, as males are often quite aggressive. We obtained the first record of two females competing for access to a male and also to nesting material. Time invested in courtship behaviour and mating was not an indication of breeding success, with failures to breed more likely during fertilization, nest building or incubation. We have shown evasiveness and control of breeding behaviours by female platypuses and the importance of these behaviours in captivity for successful breeding.