Parasites and their effects on host physiology, movement and behaviour

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Studies of animal behaviour, physiology and movement assume that individuals are healthy and performing optimally in ways which are adapted to their survival. However, wild animals face numerous ecological challenges, such parasite infection, that compromise their health, reduce their performance capacity, impair their movement abilities and, ultimately, lower their fitness. The role of parasites in influencing animal movement behaviours (i.e. where and when to move) and locomotor performance capacity (i.e. ability to execute a movement behaviour) is largely unexplored, perhaps because animals often hide outward signs of sickness, and parasites tend to be inconspicuous. I will use the following freshwater and marine fishes and their associated ecto- and endoparasites as model systems to address fundamental knowledge gaps in our understanding of how parasites shape the movement behaviour and locomotor performance of their hosts: A) sunfishes (Lepomis spp.) infected with trematodes (Uvulifer spp.) from lakes in Quebec and B) French grunt (Haemulon flavolineatum) and brown chromis (Chromis multilineata) infected with Anilocra isopods from reefs in the US Virgin Islands. My group will address four overarching quesions: Q1) Do fishes use prophylactic behaviours to avoid infection? We will evaluate whether bluegill and pumpkinseed sunfish use visual and/or odour cues to avoid infected conspecifics and habitats. Q2) Do infected hosts use therapeutic behaviours to reduce or recover from infection? In laboratory and field experiments, we will test whether infected sunfishes display behavioural fever by seeking out warm microhabitats to help them recover from trematode infection. Q3) Do parasites affect host locomotor performance? As a test of the performance compensation hypothesis, we will assess whether ectoparasite infection affects the aerobic swimming and fast-start kinematic performance of French grunt and brown chromis across different life stages, and whether endoparasite infection similarly affects locomotor performance in sunfish. Q4) Does impaired locomotor performance affect patterns of host migration? We will test whether partial migration in infected French grunt is related to impairments in individual performance capacity caused by ectoparasites. Answers to these questions will provide much needed empirical data for predicting the consequences of interactions between hosts, parasites and movement patterns of animals in a changing world.