OJEDA valeria Susana
Can the intake of anti-parasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?
MASELLO, J.+20 AUTORES; OJEDA, V
PARASITES AND VECTORS
BIOMED CENTRAL LTD
Lugar: Londres; Año: 2018 vol. 11 p. 357 - 372
Parasites can cause important ecological and evolutionary pressures.Consequently, hemoparasites became the focus of recent avian studies. Infectionvaries significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors,life history, and immune defence. Feeding behaviour can also be relevant both throughincreased exposure to vectors and consumption of secondary metabolites withpreventative or therapeutic effects that can reduce parasite load. However, the latterhas been little investigated. Psittaciformes (parrots and cockatoos) are a good model toinvestigate these topics, as they are known to use biological control againstectoparasites and to feed on toxic food. We investigated the presence of avian malaria(Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon),unicellular flagellate protozoa Trypanosoma, and microfilaria in 19 Psittaciformesspecies from a range of habitats in the Indo-Malayan, Australasian and Neotropicalregions. We gathered additional data on hemoparasites in wild Psittaciformes from theliterature. We considered factors that may control the presence of hemoparasites inPsittaciformes, compiling information on diet, habitat, and climate. Furthermore, weinvestigated the role of diet in providing anti-parasitic secondary metabolites that couldbe used as self-medication to reduce parasite load.Results: We found hemoparasites in only two of 19 species sampled. Among them, allspecies that consume at least one food item known for its secondary metabolites withanti-malarial, trypanocidal or general anti-parasitic properties were free fromhemoparasites. In contrast, the infected parrots do not consume food items with antimalarialor even general anti-parasitic properties. We found that the two infectedspecies in this study consumed omnivorous diets. When we combined our data withdata from studies previously investigating blood parasites in wild parrots, the positiverelationship between omnivorous diets and hemoparasite infestation was confirmed.Individuals from open habitats were less infected than those from forest.Conclusions: The consumption of food items known for their secondary metaboliteswith anti-malarial, trypanocidal or general anti-parasitic properties as well as the higherproportion of infected species among omnivorous parrots could explain the lowprevalence of hemoparasites reported in many vertebrates.