| Popis: |
1. The numbers of male and female Painted Reed Frogs (Hyperolius marmoratus) were monitored over 28 consecutive nights at the height of the breeding season. Despite arguments that male and female numbers should be highly correlated we found that only 32% of the variance in female numbers was explained by the number of males present. 2. To assess our prediction that attendance was determined by considerations other than optimal access to mates we modelled attendance patterns using a wide range of environmental variables. 3. Male and female attendance patterns were best described by different models. For males, 76.6% of the variance in nightly attendance was accounted for by the following variables: a constant, evaporation, pond depth on the previous night, rainfall, atmospheric pressure at 1400 h. wind on the previous day and the number of days since rain. The nature of the inter-relationships suggest that males are primed to attend the chorus unless conditions are liable to lead to increased evaporative water loss. 4. The female model accounted for 87.8% of the nightly variation in attendance and incorporated the following variables: number of males present, number of hours of sunshine on the previous day, wind on the previous day, rainfall 2 days previously, humidity at 1900 h and minimum temperature. The data suggest that females are more selective about the timing of attendance than are males. Specifically, it appears that females attend when conditions favour the rapid development of larvae. |
