## 4 Discussion
### Why Should Multi-Site Studies Be Favored?
#### 4.1.2 To Assess the Spatial Variability Due to Habitat, Slope, Altitude and Hydrography  
The inter-slope and inter-altitude study revealed a wide disparity in activity times and persistence indices. The pseudo-medians of the significant differences corresponded to between 17% and 41% of the HaDailyref (at Peyreget, ranging from 0.75 to 1.83 (Table 3) in regard to HaDailyref = 4.5 h). On 70% of significant differences, one persistence index was above 1 and the other below. Depending on the studied locality, the persistence index indicated the population persistence over all three years (NH locality) or only a few years (other localities). Thus, the study of a single locality is not representative of the study site [62] making spatial replication of sampling mandatory to measure the variability observed at the site and incorporate it into population management decisions [114]. For 70% of the detected differences, as expected, HaDaily pseudo-medians were greater in the north localities compared to the south and high compared to low. Over one on the three years, the activity time safety margins were also consistent with the expected, greater in the north and at high altitude than in the south and at low altitude. However, these patterns were not observed in the other years. For instance, in 2017, the daily activity times were higher at SL than at NL and SH and the persistence indices also reflected these differences. As the activity time depends on two thresholds, habitat suitability may be limited by too low or too high temperatures. In 2017, the percentage of operative temperatures (Te) included in the voluntary thermal range was only 24% for NL and 28% for SH localities while it was 37% for SL. Moreover, the percentage of Te above the VTmax was higher at NL than at SH than at SL, while it was more similar below the VTmin (Figure 11). These observations indicate that the activity time would be rather limited by too high temperatures. Slope orientation and habitat could explain these surprising results. Indeed, the in nature study did not allow to define sites strictly exposed to north and south and thus raised the important effect of slope orientation. Moreover, the scree diversity provides a thermal conductivity range, which is lower when the rock density is low and the stone blocks are distant (the scree type on SL) and higher when the scree is compact, wide, and broad (the scree type on NH and SH) [110]. Thus, a low elevation habitat may be more favorable than a high elevation habitat. All these results partially challenge the hypothesis that species would migrate to higher altitudes with more favorable temperatures [58; 69] and highlight the role of slope orientation and habitat on the micro-climate felt by individuals [62; 115; 116]. Finally, the study of inter-site variability showed significant differences between sites at similar altitudes. In our study case, the HaDaily pseudo-median was always higher at the Peyreget site than at the Anglas and Arrious sites regardless of the replicate. Furthermore, HaDaily pseudo-medians at Anglas were higher than at Arrious. These differences are coupled with persistence indices indicating an activity time safety margin of almost 20% of the minimum total activity time required for recruitment at a site over a year (at the Peyreget site, PI = 0.195) while the indices indicate extinction probabilities for 3 of the 4 biomimetic loggers deployed on the two other sites (Anglas and Arrious). However, these results seem to be at odds with the observed lizard densities as the Arrious site has the highest while the Peyreget site has the lowest. Here, the persistence index is only calculated from the activity time, which is itself only calculated from the Te, while other environmental parameters such as wind and humidity influence it and therefore the persistence [20; 117; 118]. At the Arrious site, local naturalists have already noticed that individuals were closer to the river when temperatures were higher ([PERSON] and [PERSON], personal communication) (Figure 2).