Fig 1.
Changes in body weight as a result of overnight dehydration and rehydration treatments in Loxopholis ferreirai (left) and L. percarinatum (right) lizards.
Fig 2.
Repeated observations of the VTmax in relation to individuals’ hydration level (A) start temperature (B) and heating rate (C), measured in Loxopholis ferreirai (Orange circles) and L. percarinatum (blue triangles) lizards. Points indicate observations, and bars represent predicted values by the best-supported model, which includes the three factors (see methods). Graphs plotting residual values can be viewed in S1 Fig in S1 File.
Fig 3.
Map of thermal risk variation, based on the response of lizards to dehydration for Loxopholis percarinatum across the amazon basin.
Points represent known populations of these lizards. Pixels in yellow to orange represent areas reaching negative thermal margins, while green represents areas where thermal margins remained positive. A and B represent the difference between the median VTmax of hydrated (A) or dehydrated (B) lizards and the mean of the yearly maximum air temperatures at any pixel. In C to F, the same colors show the number of hours that body temperatures exceeded the VTmax for hydrated and dehydrated lizards when allowed to seek refuge down to 10 cm under wet leaf litter in the shade. C represents a “best” situation, with hydrated lizards (VTmax = 31.2°C), 100% tree cover, full rain, and ability to burrow down to 10 cm. Instead, D to F show the expected effects of altering some of these parameters. D represents thermal risk after a 50% decrease in rainfall, E shows risk after a decrease of 20% in tree cover, and F shows the risk for lizards with VTmax = 28.8°C, The median VTmax for L. percarinatum under 95% of their maximum hydration level.
Table 1.
Effects of changing different parameters on the extent (number of sites across the Amazon basin), duration (number of yearly hours over the VTmax), and number of known populations affected by thermally stressful events for L. percarinatum across the Amazon’s basin.
Parameters: Mass = body mass, VTmax = voluntary thermal maximum, Moist_surface = percentage of surrounding surface that can evaporate water, Maxdepth = maximum depth to which a lizard can dig, Rain = amount of rain falling, Maxshade = Maximum percentage of tree cover that the lizard has access to. See methods to consult the levels compared among factors. See S3-S5 Tables in S1 File for full results.