Effects of salinity on rates of infestation of waterbirds by haematozoa

A recent hypothesis suggested that migration patterns in waders and other birds could be shaped by the distribution of parasites and diseases. This hypothesis assumes a reduced exposure to parasites in species living in saline habitats. To test this assumption. the number of species of haematozoa and rates of infection reported for bird species living in fresh and salt‐water habitats were compared. Speceses living in more saline habitats had fewer haenatozoic parastte species than freswater birds., Relative frequency of infection was also lover in saltwater species. Neither phylogeny not the number of individuals examined for blood parasies in each species explained these diferencfes. Thus there is indece evidence hat birds living in saline habitats have a reduced risk of being parasitized by haematozoa. Probably due to a reduced abundance of the inverebtare vectors.