ST. PAUL, Minn., May 27 (UPI) -- The evolutionary impetus for animal migrations isn't always obvious.
Why would species decide to expend such tremendous amounts of energy to travel so far? What compels them to travel through vastly different types of habitat and climatic conditions?
New research suggests an escape from parasites might be one motivating factor.
A team of scientists from the University of Minnesota and the University of Neuchâtel in Switzerland hypothesized that the varied environmental conditions along a migratory route might help migrating species flush out parasites.
The scientists point out that fish and crustacean species in the pet and aquaculture trade are often dipped in water of different salinity to excise ectoparasites and diminish skin infections.
Researchers built a model to determine whether such benefits would be significant enough in the real world to drive evolutionary change. Their math suggests migratory patterns feature biological conditions that favor the reduction of pathogens, and that benefits could be large enough to inspire migration and partial migration.
"Although parasite loss via changes in the host's internal or external environment have not been explicitly studied in the context of migration," a news release for the American Society of Naturalists reads, "the researchers highlight a number of empirical systems where there is potential for migrants to benefit from losing their parasites."
The scientists hope their findings -- published in the journal The American Naturalist -- will serve as a jumping-off point for further exploration into the motivations of animal migration.