(a) Richness and abundance
We recorded 613 individual lizards belonging to seven species (individuals in brackets), i.e., Ophisops elegans (462), Phoenicolacerta troodica (55), Laudakia cypriaca (19), Acanthodactylus schreiberi (69), Chamaeleo chamaeleon (3), Ablepharus budaki (4), and Chalcides ocellatus (1). Alykos river hosted the highest overall abundance, i.e., 241 individuals, followed by Peristerona river with 212 individuals, and Mesa Potamos river with 160. The population size of O. elegans, which is the most common lizard in Cyprus, was 164, 180, and 118 individuals in Alykos, Peristerona, and Mesa Potamos, respectively. Abundance per species and transect line is given in Table 2.
(b) Abundance inside vs outside Natura 2000 areas
Highest total abundance was found inside Natura 2000 areas, with 351 individuals, in contrast to 262 individuals outside Natura 2000 areas. Alykos river hosts 167 individuals inside Natura 2000 areas compared to 74 individuals outside. The numbers of individuals inside and outside the Natura 2000 site at Mesa Potamos were almost the same, i.e., 81 and 79 outside, while in Peristerona river, individuals outside Natura 2000 areas were higher than those inside, i.e., 103 vs 109 individuals, respectively. Results on each species’ abundance inside vs. outside Natura 2000 sites in each river can be seen in Table 2.
(c) Effects of environmental heterogeneity on diversity and richness
The Habitat Diversity Metric (HDM) described in Methods, exhibited extensive variance among transect lines regardless of their location inside or outside Natura 2000, even among lines of the same river (Table 3).
Species diversity and richness were not associated with any of the explanatory variables used in the analysis (Table 4). The variance explained by these two models was low (10% and 7% respectively).
(d) Effects of environmental heterogeneity on the abundance of four species
The HDM varied also widely among species, as expected by the different ecological features of each species. For Ophisops elegans the highest HDM was observed in Mesa Potamos river, in the first transect line inside Natura 2000 (i.e. 771.5), while the smallest in the same river, in the third transect line, outside Natura 2000 (i.e. 285.5). For Phoenicolacerta troodica the highest value was found in Mesa Potamos river’s first transect line, outside Natura 2000 (i.e. 771.5), while the lowest in Peristerona river, in the third transect line, outside Natura 2000 (i.e. 341.5). Laudakia cypriaca exhibited its highest value in Peristerona river, third transect line, outside of Natura 2000 (740.5) and its lowest in Alykos river, second transect line, again outside of Natura 2000 (257). Finally, for Acanthodactylus schreiberi, the highest value was found in Mesa Potamos river, third transect line, inside Natura 2000 (722.5), while the lowest in Peristerona river, third transect line, inside Natura 2000 (377).
The abundance of Ophisops elegans was negatively associated only with elevation (Table 5, Fig2A). Phoenicolacerta troodica was not associated with any of the variables included in the analysis. The abundance of Laudakia cypriaca was associated with Natura 2000 sites, elevation, and season (Table 5). On average, there were more individuals outside Natura 2000 sites (Fig2B), in sites at higher elevations (Fig2C), and during the summer months (Fig2D). These three variables together explained ca. 45% of the variation in the abundance of L. cypriaca across all sites. Lastly, the abundance of Acanthodactylus schreiberi was associated with Natura 2000 sites and with elevation (Table 5). There were more individuals inside the Natura 2000 sites (Fig2E) and at sites at lower elevations (Fig2F). The amount of variance explained by the model was ca. 98%.