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Objectives

Assess the spatial and temporal variations in the abundance of common bat populations.

Specific actions

Standardized counts of common bats

Project created
Mainland France

Type of project : Field

Participation period : Spring/summer

Level of involvement : Case by case

Participate

Pipistrelle commune
Photo credits CC BY-SA

Project description

This observatory is part of the Vigie Nature network.

The protocol we developed is based on listening to and recording the ultrasonic sounds made by bats. These calls are a sort of acoustic signature specific to each species. Bats use them to help them navigate and to detect their prey when flying at night and when hunting. They also use these ultrasonic calls to communicate with and recognize other bats. The boundary between ultrasonic sounds emitted for echolocation and those used for inter-individual communication is rather blurred: by simply emitting an echolocation call, a bat is sending a signal to other bats and informing them of its identity, activity and availability of prey.

However, communication signals are generally longer and more complex. The chosen observation method (time-expansion detector recording) is based on converting ultrasonic sounds into sounds that are audible to the human ear. This conversion preserves the sound characteristics of the original signal and allows for computer analysis of the sonograms (graphs used to visualize sound). This approach makes it possible to limit observer effects and, most importantly, conduct retrospective analyses. The study of bats is relatively recent and there is still much to learn about these species. In the early nineties, scientists discovered that bats known as the common pipistrelle, one of the most widespread species in Europe, were actually two different species, each emitting calls with different ultrasonic frequency ranges. There are three versions of the protocol: one by car, one on foot and a third using recordings from fixed points.

Co-managers

Yves Bas

Yves Bas

Post-doc

Muséum national d’histoire naturelle (MNHN)

CESCO

Yves Bas

Jean-François Julien

Jean-François Julien

CR CNRS

Muséum national d’histoire naturelle (MNHN)

CESCO

Jean-François Julien

Christian KERBIRIOU

Christian KERBIRIOU

Maître de conférences au Muséum national d’Histoire naturelle – Sorbonne Université - Responsable .scientifique Vigie-Chiro & Plages vivantes

Sorbonne University

Centre d’Écologie et des Sciences de la Conservation (CESCO)

Julie Marmet

Julie Marmet

Ingénieur

Muséum national d’histoire naturelle (MNHN)

CESCO

Julie Marmet

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