An urge to fill a knowledge void: Malaria parasites are rarely investigated in threatened species

Here, we provide evidence that the occurrence of haemosporidian parasites is poorly documented in most bird species in high extinction risk categories, according to the International Union for Conservation of Nature (IUCN) [1], and urge parasitologists, wildlife epidemiologists, ornithologists, and ecologists to study parasite prevalence and diversity in threatened species. Assessing the occurrence of haemosporidians in endangered birds is of utmost importance because parasites are often alleged to contribute to the risk of extinction [2], the percentage of the world’s bird species now considered as threatened is high and increasing [1], and blood parasites are common in wild bird populations [4] and can be easily screened using blood samples. The data generated in this line of research will be essential also for parasite conservation, as parasites may themselves be at risk of extinction nowadays [9], especially parasites specialized on threatened, rare, or geographically restricted hosts (e.g., the nearly extinct Felicola isidoroi, host-specific louse of the Iberian lynx [10]). CR, Critically Endangered; EN, Endangered, IUCN, International Union for Conservation of Nature; LC, Least Concern; NT, Near Threatened, VU, Vulnerable. https://doi.org/10.1371/journal.ppat.1008626.g001 Vulnerable, Endangered and Critically Endangered bird species may be underrepresented in MalAvi because the occurrence of haemosporidians in these host species is rarely assessed or because studies not finding haemosporidians are not reported in MalAvi. [...]data potentially available in published papers and in the grey literature (e.g., technical reports, zoo reports, etc.) should also be explored.