ANURAN DEVELOPMENT, DENSITY AND DIVERSITY IN RELATION TO AGRICULTURAL ACTIVITY IN THE HOLLAND RIVER WATERSHED, ONTARIO, CANDAD (1990-1992)

摘要

Signficantly lower anuran species diversity and density was recorded in a vegetable growing area relative to upstream and downstream sites in the Holland River watershed. Ontario, Canada. Egg hatching success and tadpole deformity rates fo American toads (Bufo americanus americanus), green frogs (Rana clamitans melanota) and northern leopard frogs (rana pipiens) egges in water from field sites and control water were assessed. Compared to the control and the upstream site, the total abnormality rate (unhatched eggs plus deformed tadpoles) was higher for American toads in water from the agricultural and downstream sites.