Effect of Climate Change on the Distribution of a Critically Threatened Specie

Abstract

Climate change (CC) is modifying the habitat and distribution of wild fauna, causing distribution area reduction and/or altitudinal or latitudinal movements of species in response to increased temperatures and changes in precipitation. This increases the risk of species extinction, particularly for those with small population sizes, habitat specialists, microendemics and/or those with already restricted distributions. We examine how the effects of CC could influence the distribution and availability of habitat for the critically threatened and endemic species: the Tehuantepec jackrabbit (Lepus flavigularis) as well as the species of grasses on which it feeds. Our models were constructed using Maxent. Occurrence data of jackrabbits and grasses from the years 1959 to 2014 were analyzed, along with climatic and slope variables for three time periods, present (2014) and future (2050 and 2070). The climatic variables were taken from WorldClim (resolution: 30”), utilizing the HadGEM2-ES model with scenarios 4.5 and 8.5. Potential distribution models estimate an area of 9,274 ha of habitat suitable for the jackrabbit in 2014, with a 19.3% increment in this area to 11,071 ha by 2070 with scenario 4.5 and 9% increment with an area of 10,111 ha by 2070 with scenario 8.5. According to a Jackknife analysis, Precipitation of Wettest Month (BIO13), and Precipitation of Warmest Quarter (BIO18) are the variables that contribute most to the construction of the potential distribution models of L. flavigularis, from 2014 to 2070. Future scenarios (4.5 and 8.5) estimate temperature increase and precipitation reduction in places where jackrabbits and grasses currently inhabit. Also, these scenarios estimate an increase in areas with suitable climatic conditions in the future. However, anthropogenic factors (not considered in this study) have influenced the distribution and retention of the populations of L. flavigularis in the study area, so the outlook of the species is not encouraging. It is clear that CC will have an effect on the distribution of this critically threatened and endemic species, through modification of the area and distribution of its available habitat.