## Materials and Methods
### Activity Time Computing from Te Measurements  
Several methods have been developed to define the activity time and conversely the restriction time. Among the first ones, the restriction time can be defined when Te is greater than CTmax. However, this method suggests that individuals can be active even when body temperature is below CTmin [11]. Other authors explained that the restriction time is set when Te is above the upper limit of the preferred thermal range and the activity is limited by a lower value [63]. More recent studies have put forward a two-threshold method; the activity time is defined when Te is within the activity thermal range, bounded by the voluntary temperatures VTmin and VTmax, it is also called the voluntary thermal range (VTR) [83; 84; 100]. VTmin and VTmax are the 5 th and the 95 th percentiles of the preferred temperature distribution [83]. They also correspond to the lowest and the highest cloacal temperatures measured in the field on active individuals [84].  
In this paper, we have calculated activity time using the two-threshold method because it appears to be more biologically relevant than the other and is more often used in recent papers [63; 83] in line  
Figure 2: In France, in the department of Pyrenees-Atlantiques (in green on the France map in the top left), nine biomimetic loggers have been deployed on three study sites: Anglas—An\({}_{1}\) and An\({}_{2}\); Arrious—Ar\({}_{1}\) and Ar\({}_{2}\); and Peyreget—NL, NH, SL, SH, and P. The highest density is observed at the Arrious site (in red), the lowest at the Peyreget site (in yellow). The Anglas site (in orange) has a medium density. The hydrographic network is drawn in blue. Map source: Stamen, extracted with the get_map function on R.  
with critical assessment by [84]. This method requires the definition of VTmin and VTmax for each of our study populations because the eco-physiological characteristics may differ between populations, as has been demonstrated for critical temperatures [101]. However, determining them experimentally would have been time-consuming and invasive. Other studies had been carried out on populations spatially close to ours, so we have favored the use of their results with the hypothesis that they presented similar thermal characteristics to the closest population studied in the bibliography [102]. We defined VTmin and VTmax using the [12] study conducted on the Blue Lake of the Bigorre Massif. This study was the best compromise between the geographical distance of our study sites and the availability of detailed data in the field. Thus, the VTmin was 20.8 \({}^{\circ}\)C and the VTmax was 35.2 \({}^{\circ}\)C for the three populations studied. For each measurement of Te occurring during the day, defined from sunrise to sunset, if included in the activity thermal range, the 10 min (the recording frequency) was defined as the activity time. Then, for each day, they were summed to obtain daily activity hours (HaDaily). Finally, for each recording (6 in 2017 and 2018; 9 in 2019), we summed daily activity hours over all days of the breeding period to obtain the total activity time (HaTot) (Equation (1)). For each breeding days \(j\), daily activity hours is defined as  
\[HaDaily_{j}=10\times HaCount_{j}/60\]  
where \(HaCount_{j}=\sum_{i}\mathds{1}_{\{Te_{ij}\in[VTmin,VTmax]\}}\), with \(\mathds{1}_{\{\cdot\}}\) being the indicator function and \(Te_{ij}\) being the \(i\)th measurement of day \(j\). Thus, total activity time is  
\[HaTot=\sum_{j}HaDaily_{j} \tag{1}\]