Long-term monitoring of rodent and shrew communities in a biodiversity hot-spot in Austria using barn owl (Tyto alba) pellets

Abstract

Rodent and shrew populations are key components of many animal communities around the world. However, their population dynamics and the factors influencing their abundance are still not well understood. We analyzed rodent and shrew community composition and abundance at a UNESCO world heritage site, the Neusiedler See in Eastern Austria, using barn owl pellets. We identified temperature (mean and minimal monthly temperature) as well as maximum precipitation per day as significant drivers of the rodent and shrew presence. Our analyses showed that increased temperatures and dry summers will challenge most of the analyzed species and most likely lead to decreased abundances, which will also affect the already threatened Pannonic root vole (Microtus oeconomus mehelyi). Increased drainage efforts in this area would also lead to less ground water and dryer soil and therefore damage the local rodent and shrew populations. We show that barn owl pellets are a highly efficient way of monitoring rodent and shrew populations over a large area and enable researchers to decipher the factors influencing population and community dynamics. The use of pellet data, therefore, may still be one of the most efficient methods of assessing small mammal populations and their change over time.