Use of removal sampling to estimate abundance of larval salamanders (Salamandra salamandra) in streams

In an era of ongoing biodiversity loss, there is a need for reliable methods that can be used to estimate population size and trends. Removal sampling can be used to estimate the abundance of a single population or of multiple spatially distinct populations of animals. Because multiple removal passes are made during a single visit to a population, it may be very efficient in terms of logistics. Here, we use removal sampling and hierarchical models to estimate the abundance of salamander (Salamandra salamandra) larvae in 15 first- and second-order streams. Detection was positively affected by sampling day, suggesting that observers improved their ability to detect salamander larvae. Abundance was positively affected by the number of pools in the streams. Overall, the removal sampling method performed well despite small sample size. Removal sampling may be a useful method for monitoring amphibians.