Triphenyltin compounds are used globally in agriculture as fungicides for a wide variety of crops. Their persistence in aquatic habitats and toxicity make them of special concern to amphibian species using temporary ponds or lakes for critical life-history functions. The effects of short-term exposure to three concentrations (5, 10, 20 pg/L) of triphenyltin chloride (TPT) were assessed for the swimming and feeding behavior of tadpoles of the European frog, Rana esculenta. The proportion of time spent swimming declined 33.8% with increasing TPT level. Treatments also had a significant effect on the proportion of time spent feeding, initially increasing in the acetone and lowest TPT treatments, but thereafter declining 19.6% with increasing TPT level. Tadpoles also compensated for reduced swimming by spending an increased proportion of activity time on feeding, but even this compensation declined at the highest TPT levels. Reduced swimming activity and food intake are likely to result in decreased growth and development as well as negatively influence adult traits such as size at maturity, survival to first reproduction, and fecundity.' . -

Female yellow dung flies Scathophaga stercoraria oviposit on the dung surface, which is extremely uneven and other eggs are often already present. We examined the effects of these features on egg placement. We found that: 1. females preferred to lay on small hills on the dung surface and avoided depressions and points; and 2. they ignored the presence of other eggs. These results were confirmed in a field experiment, where the pattern of egg distribution on artificially formed dung pats was consistent with the predictions from the laboratory results. We further showed that survival to adult emergence was best when laying sites were experimentally manipulated so that the eggs were apparently laid on small hills, avoiding the drying effects of small points in the dung and possible drowning by (simulated) rain when laid in depressions in the dung surface. A female dung fly is clearly capable of making subtle decisions about the placement of her eggs, thus increasing her reproductive success.

Triphenyltin compounds are used globally in agriculture as fungicides for a wide variety of crops. Their persistence in aquatic habitats and toxicity make them of special concern to amphibian species using temporary ponds or lakes for critical life‐history functions. The effects of short‐term exposure to three concentrations (5, 10, 20 μg/L) of triphenyltin chloride (TPT) were assessed for the swimming and feeding behavior of tadpoles of the European frog, Rana esculenta. The proportion of time spent swimming declined 33.8% with increasing TPT level. Treatments also had a significant effect on the proportion of time spent feeding, initially increasing in the acetone and lowest TPT treatments, but thereafter declining 19.6% with increasing TPT level. Tadpoles also compensated for reduced swimming by spending an increased proportion of activity time on feeding, but even this compensation declined at the highest TPT levels. Reduced swimming activity and food intake are likely to result in decreased growth and development as well as negatively influence adult traits such as size at maturity, survival to first reproduction, and fecundity.