Egg production in the Common toad, Bufo bufo

The number and size of eggs produced by the Common toad (Bufo bufo) was investigated at a site in southern England. There was a trend within the population as a whole for egg weight, egg number and ovary weight to increase with female size, as defined by body length and body weight. However, with use of partial correlation analysis to remove the effects of female size from the data, some of these trends changed. Thus, for females of the same size, although egg number increased with ovary weight, no significant correlation was found between egg weight and ovary weight whilst egg weight became negatively correlated with egg number. The possible significance of variation in egg weight on tadpole survival and female reproductive success is discussed.