Haemosporidian parasite prevalence, parasitemia, and diversity in three resident bird species at a shrubland dominated landscape of the Mexican highland plateau.

María Teresa Reinoso-Pérez,Julio César Canales-Delgadillo,Lina Riego-Ruiz,Leonardo Chapa-Vargas

doi:10.1186/s13071-016-1569-3

Abstract

BackgroundStudies of avian haemosporidians allow understanding how these parasites affect wild bird populations, and if their presence is related to factors such as habitat loss, degradation and fragmentation, and climate change. Considering the importance of the highland Plateau of Mexico as part of the North American bird migratory route and as a region containing important habitat for numerous bird species, the purpose of this study was to document haemosporidian species richness and how habitat degradation, bird body condition, and distance from water sources correlate with bird parasitemia.MethodsWe assessed the presence of avian haemosporidians in three resident bird species through microscopy and PCR amplification of a fragment of the haemosporidian cytochrome b gene. Average parasitemia was estimated in each species, and its relationship with habitat degradation through grazing, bird body condition and distance from water bodies was assessed.ResultsHigh levels of parasitemia were recorded in two of the three bird species included in this study. Four lineages of haemosporidians were identified in the study area with nearly 50 % prevalence. Areas with highly degraded shrublands and villages showed higher parasitemia relative to areas with moderately degraded shrublands. No strong relationship between parasitemia and distance from water bodies was observed. There were no significant differences in prevalence and parasitemia between the two bird species infected with the parasites. Two of the sequences obtained from the fragments of the parasite’s cytochrome b gene represent a lineage that had not been previously reported.ConclusionsHaemosporidian diversity in arid zones of the Mexican highland plateau is high. Shrubland habitat degradation associated to the establishment of small villages, as well as tree extraction and overgrazing in the surroundings of these villages, significantly enhances parasitemia of birds by haemosporidians.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1569-3) contains supplementary material, which is available to authorized users.

Highlights

Studies of avian haemosporidians allow understanding how these parasites affect wild bird populations, and if their presence is related to factors such as habitat loss, degradation and fragmentation, and climate change
One study in Arizona reported prevalence values from 0 to 80 %, and parasitemia by Haemoproteus related to nesting height, but no infections by Plasmodium and Leucocytozoon, and speculated that these results could be related to a number of factors including resistance to parasites, ecological barriers, or the absence of Plasmodium and Leucocytozoon vectors in this environment due to the limited water availability [4]
Our study reports the first records of haemosporidian parasites in avian populations from the highland plateau of Mexico and the effects of environmental variables on parasitemia

Summary

Introduction

Studies of avian haemosporidians allow understanding how these parasites affect wild bird populations, and if their presence is related to factors such as habitat loss, degradation and fragmentation, and climate change. Haemosporidan parasites are transmitted by 17 genera of blood-sucking insects of the order Diptera [1, 2] The study of these parasites allows the understanding of various aspects of avian ecology. Diversity of haemosporidian lineages is high throughout the globe but tend to be higher in continents than in islands, and in tropical than in temperate regions [13]. Knowledge related to factors influencing patterns of bird parasitism by haemosporidians in dry regions of the Americas is rather limited. A study in arid zones of Venezuela reported 41 % haemosporidian prevalence and high species diversity including seven lineages from the genus Plasmodium and ten from Haemoproteus. It was reported that humidity and temperature influence vector distribution and abundance [3]

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