About the Authors

Lorenzo Quaglietta

lorenzo.quaglietta@uniroma1.it

Affiliation Department of Biology and Biotechnology “Charles Darwin”, University of Roma ‘La Sapienza’, Roma, Italy

Bruno Herlander Martins

Affiliation CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos, Porto, Portugal

Addy de Jongh

Affiliation Dutch Otterstation Foundation, Leeuwarden, The Netherlands

António Mira

Current address: Centro de Investigação em Biodiversidade e Recursos Genéticos – University of Évora, Évora, Portugal

Affiliation ICAAM – Mediterranean Agricultural and Environmental Sciences Institute – University of Évora, Évora, Portugal

Luigi Boitani

Affiliation Department of Biology and Biotechnology “Charles Darwin”, University of Roma ‘La Sapienza’, Roma, Italy

Competing Interests

AdJ is the Director of the Dutch Otterstation Foundation and the developer of the GPS system and Python script. Although this could be seen as a competing interest, the Dutch Otterstation Foundation is a non-profit NGO (Dutch Representative of IUCN/SSC OSG), and it has developed this system for its own purposes. Now that it is successful it is also sold in low volumes to others, but the small profit that is made goes straight back to their environmental work, as they may confirm. Moreover, neither AdJ nor the Dutch Otterstation Foundation had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript, with AdJ contributing only by correcting English mistakes and providing some details on the used material. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: LQ. Performed the experiments: BHM LQ. Analyzed the data: LQ. Contributed reagents/materials/analysis tools: AM AdJ LQ. Wrote the paper: BHM LQ AdJ LB AM.