Otter post mortem management and research in Italy. Current situation, limits and perspectives

In recent years, the expansion of otter (Lutra lutra) range has been recorded in a number of European countries. This positive trend has occurred also in Italy, although otter distribution is still limited to the southern regions and the species is considered as endangered. Increasing numbers of dead otters were reported during the last ten years in Italy, likely due to increasing population size. Carcass reports usually provide spatial data (the location where the otter was found) that enable the investigation of the scene of death. In case of road traffic casualties (RTC) or human-related mortality (e.g., fyke-net accidents), this is considered of primary importance in order to identify and mitigate risks for individual otters. However, such approach assumes RTCs or any human-related mortality to be a threat, even in the absence of any attempt to quantify the relative influence of each cause-specific mortality on population survival. To properly evaluate threats, a first requirement is to collect detailed mortality and pathology data. This, in turn, requires that the reported carcasses are timely recovered and submitted for necropsy. Post-mortem (PM) examination of otters provides evidence of diseases and causes of death, and data on the age, sex and reproductive status of dead individuals. This information, coupled with the estimation of population sizes or adequate surrogates, may be used in population modelling and assessment. However, such important data need to be recorded by (preferably one or a few) experienced teams based on agreed protocols. In February 2010 a workshop arranged by the IUCN Otter Specialist Group – Europe has been held in Denmark to discuss PM procedures in Europe and practice necropsies. The workshop highlighted a great variation in schemes for ‘reporting-recovering-PM analysis’ of otters among European countries and stressed the importance of common standards and collaboration. Here we describe the current situation and limits of post-mortem management of otters in Italy in relation to the key points outlined above and in the light of national laws and indications provided by the national action plan for otters. We discuss future perspectives and possible improvements of PM procedures focusing on systematic collection of otter corps and standardized, high-quality PM analyses. In particular, we present an ongoing research project intended to contribute to fill major gaps in otter PM management and research: the RECAL project. A multi-disciplinary team, with otter ecologists and pathologists has begun to work on carcasses collected in the core area of otter distribution in Italy (Cilento and Vallo di Diano National Park), by applying standardized protocols discussed in Denmark in 2010, attempting to create an effective organization for carcass recovering and developing tools for data recording. At present the RECAL research group is the only specialist team that have practiced multiple necropsies of otters in Italy.[...]