When natural environments change, species may shift their distributions, adapt to novel conditions, or die out. Consequently, accelerating climate change is already recognized as leading to considerable range expansion and contraction, evolutionary changes, and extinction for hosts, parasites, and diseases through the Arctic (e.g., Kutz et al., 2013; Meltofte et al., 2013). Ultimately, these perturbations have consequences for wildlife and humans at high latitudes (e.g., Dudley et al., 2015). Complex host-parasite systems are critical proxies for understanding change in northern regions due to species interactions that determine the distribution of parasites and disease over space and time (e.g., Hoberg et al., 2012, 2013). Life histories for helminth parasites (tapeworms, flukes, roundworms) often involve circulation among mammalian hosts (where adult parasites reside) and other vertebrate and invertebrate species (where larval or developing parasites reside). Other parasites (viruses, bacteria, protozoans) circulate through vectors such as blood feeding arthropods or through direct transmission. These complex life cycles are closely tied to environmental conditions, define linkages across communities, and scale from individuals to ecosystems.
