Growth and age at sexual maturity in common toads (Bufo bufo) from two sites in Southern England

Abstract

Growth and age at sexual maturity in the common toad, Bufo bufo, were investigated at two sites (Portland, Purbeck) in southern England between 1981 and 1985. The body length of males and females spawning for the first time (sexual age = 0) at these sites varied significantly between years, but this variation disappeared in females with a sexual age greater than 0. Male and female toads breeding for the first time at the Purbeck site were both larger and had higher growth rates than those on Portland. No reliable growth rates were obtained for females with a sexual age greater than 0 at either site. Growth was most rapid in males during the first two years following metamorphosis when 56% (Portland) and 71 % (Purbeck) of the total growth in body length occurred. The body length of newly metamorphosed toads at both sites was approximately 8 mm but increased by mid September to 14 mm on Portland and 19 mm at the Purbeck site. The earliest age at which sexual maturity was reached was 3 years for Portland males and 2 years for Purbeck males. No reliable estimates for the age at sexual maturity were obtained for females.