1. Reproductive frequency
For 1980-2000, we estimated that oviparous mothers laid at least 1 clutch of eggs within most regions with latitudes below 40 oN, while they laid more clutches at lower latitudes and elevations, with a maximum clutch number of 9 (Fig. 3a). Viviparous mothers can reproduce (1 litter of embryos) across a larger range of latitudes (from tropical areas to as far as 50 oN) and elevations than oviparous mothers (Fig. 3c). Under climate warming (2080-2100 versus 1980-2000), our model predicts that oviparous mothers will be able to produce clutches at higher latitudes (up to 54 oN) and elevations (up to Mexican plateau) and more frequently in most regions (by 1.2 on average), with a larger increment at higher latitudes, where clutch numbers were relatively low in the past (Fig. 3b). Viviparous mothers will be able to produce a litter of offspring at higher latitudes (beyond 50 oN) and elevations (high elevations at Mexican plateau) (Fig. 3d).