Reproductive Seasonality in Female Platypuses, Ornithorhynchus anatinus, in the Upper Barnard River, New South Wales.
Progesterone concentrations were determined in samples of blood, urine and faeces collected from female platypuses which were captured in the Upper Barnard River, NSW, from February to November, 1996. Mean concentrations in blood plasma were higher in July, August and September than in other months with the highest concentrations being in August. Progesterone concentrations in dried urine and faeces were highly correlated with values for blood plasma (r = 0.61, P<0.05 and 0.7 1, P<O.OI, respectively), and the coefficient of variation for progesterone determinations was lower for samples of urine and faeces than blood. There was a seasonal change in mean concentration of cortisol in blood (being elevated in May-August), but the concentrations of progesterone and cortisol in blood were not significantly correlated.