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

There is an increasing urgency in gaining greater understanding of the factors that affect vulnerability to extinction, given the current levels of species loss. Parasites often reduce host fitness and can thus exert an important influence on host population dynamics, exacerbating vulnerability to extinction. However, empirical support for the hypothesis that parasites can increase vulnerability to extinction is rare. A crucial factor limiting tests of the hypothesis is data availability. An extensive review of the literature revealed that common avian malaria and avian malaria–like haemosporidian parasites are seldom investigated in endangered birds. We stress the importance of assessing the occurrence of haemosporidians and other parasites in vertebrate species of high conservation concern.