Acoustic localization at large scales: a promising method for grey wolf monitoring

• Published in: Frontiers in Zoology
• Main Authors: Papin, Morgane, Pichenot, Julian, Guérold, François, Germain, Estelle
• Other Authors: Centre de recherche et d'observation sur les carnivores (CROC), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Program FEDER-FSE “Lorraine et Massif des Vosges 2014–2020”, the Commissariat à l’Aménagement du Massif des Vosges for the FNADT (Fonds National d’Aménagement et de Développement du Territoire), DREAL Grand Est (Direction Régionale pour l’Environnement, l’Aménagement et le Logement), Région Grand Est, ANRT (Agence Nationale de la Recherche et de la Technologie, CIFRE award), Zoo d’Amnéville, and the Parc Animalier de Sainte Croix, Fondation Le Pal Nature
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: acoustic monitoring; autonomous recorders; Canis lupus; field research; localization estimation; microphonearray; wolf howl; [SDE]Environmental Sciences
• Online Access: https://hal.univ-lorraine.fr/hal-03163531; https://hal.univ-lorraine.fr/hal-03163531/document; https://hal.univ-lorraine.fr/hal-03163531/file/s12983-018-0260-2.pdf; https://doi.org/10.1186/s12983-018-0260-2

International audience The grey wolf (Canis lupus) is naturally recolonizing its former habitats in Europe where it was extirpated during the previous two centuries. The management of this protected species is often controversial and its monitoring is a challenge for conservation purposes. However, this elusive carnivore can disperse over long distances in various natural contexts, making its monitoring difficult. Moreover, methods used for collecting signs of presence are usually time-consuming and/or costly. Currently, new acoustic recording tools are contributing to the development of passive acoustic methods as alternative approaches for detecting, monitoring, or identifying species that produce sounds in nature, such as the grey wolf. In the present study, we conducted field experiments to investigate the possibility of using a low-density microphone array to localize wolves at a large scale in two contrasting natural environments in north-eastern France. For scientific and social reasons, the experiments were based on a synthetic sound with similar acoustic properties to howls. This sound was broadcast at several sites. Then, localization estimates and the accuracy were calculated. Finally, linear mixed-effects models were used to identify the factors that influenced the localization accuracy.Results : Among 354 nocturnal broadcasts in total, 269 were recorded by at least one autonomous recorder, therebydemonstrating the potential of this tool. Besides, 59 broadcasts were recorded by at least four microphones and usedfor acoustic localization. The broadcast sites were localized with an overall mean accuracy of 315 ± 617 (standarddeviation) m. After setting a threshold for the temporal error value associated with the estimated coordinates, someunreliable values were excluded and the mean accuracy decreased to 167 ± 308 m. The number of broadcasts recordedwas higher in the lowland environment, but the localization accuracy was similar in both environments, although itvaried significantly among different ...