POLYGYNY AND DECEPTION IN THE PIED FLYCATCHER - CAN FEMALES DETERMINE MALE MATING STATUS

The polyterritorial pied flycatcher, Ficedula hypoleuca, was used to investigate the deception hypothesis, which states that mated males behave as unmated to hide their mating status from prospecting females. Previous studies on this species have shown that unmated and mated males differ in territorial presence, but not when females are present in their territories. Male behaviour after female visits may differ, however, and this was tested in the present study. Caged females were presented to males during periods of 5 min and the behaviour of the males in the following hour was recorded. Mated males were present significantly less often in their territories than unmated males. Video-recordings of male behaviour after natural female visits indicated that mated males spent less time singing than unmated males, suggesting that they were often absent from their territories. Given this difference, females can potentially determine male mating status by making repeated returns to the territories of males they have visited, and sampling the presence of the males. Field data showed that females visited their chosen mate 5-37 times before mating. A model is presented which gives the probability of rejecting mated males, depending (1) on the number of repeated visits and (2) on how many of these visits a male should be present to be classified as unmated. The model also describes one cost of such behaviour, namely that of rejecting unmated males. The model indicates that females can reject up to 87-99% of the mated males by visiting males 5-37 times. In conclusion, male deception of females may be countered by females using the repeated visits strategy.