Parasite loads and altitudinal distribution of Liolaemus lizards in the central Chilean Andes

Abstract

This study compared the distributions of ten species of Liolaemus lizards in the central Chilean Andes to the distributions of four types of parasites: malaria-causing Plasmodium, gut nematodes, ticks, and mites. We wanted to see if parasite numbers might be a factor in determining distributional limits of the lizards. We found that there was no evidence of malarial infestation of the lizards, that ticks were almost absent, that more often than not mite numbers decreased at the distributional limits of the lizards, and that gut nematodes —confined to the herbivorous lizards in our sample— may well be beneficial rather than detrimental. Rather than parasitism, other biotic interactions (e.g., predation or competition) are more likely candidates as factors influencing lizard elevational distributions, as are abiotic characteristics such as microhabitat availabilities and thermal factors.