SémiLAUM - 08 mars

Le 6 mars 2022

Population censuses of male rock ptarmigans (Lagopus muta) are conducted by point count protocol in spring (late May - early June). Several observers are placed at given points within the area and spend an hour listening to singing males trying to deduce an estimate of their number. The counting conditions are diffcult and cast doubt on the good representativeness of this protocol.

The first objective of this thesis was to quantify the counting biases. The thesis then focused on finding ways to develop new counting methods to compensate for the biases of traditional counting. The acoustic signals emitted by animals carry several levels of information, such as the identity of the transmitter.

The second part of my thesis showed that bioacoustic techniques based on acoustic differences in vocalizations were suitable to ptarmigan and that it was possible to determine the number of males in an area using the sounds they produce.

The third part of the thesis is a generalization of the method on long-term recordings under real field conditions. It was not only possible to obtain the number of males but also the time of presence of each male and to assess his reproductive status.

In conclusion, I showed the interest of the bioacoustic tool to monitor ptarmigan’s populations. My thesis opens up perspectives for futur large scale monitoring of ptarmigan’s populations.