Interaction of landscape variables on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

Abstract

Interaction of landscape variables on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico.— The loss, degradation, and fragmentation offorested areas are endangering parrot populations. In this study, we determined the influence offragmentation in relation to vegetation cover, land use, and spatial configuration offragments on the potential geographical distribution patterns ofparrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration offragments, the ratio occupied by vegetation, and the land use in 100 plots ofapproximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability ofspecies. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None ofthe environmental variables analyzed alone determined the presence/absence or the probability distribution ofparrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi-evergreen medium-height forest. Habitat fragmentation influenced the potential geographical distribution ofthese species in terms ofthe characteristics ofother environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas.