Research themes

Ecology and evolution of host/parasite interactions – The focus in my lab is on the ecology and evolution of animal parasites and their hosts. In our parasite-centred focus, we are interested in how natural selection shapes patterns of parasite growth, development, reproduction, and life-histories. In our host-centred focus, we seek to understand the nature of parasite-induced effects on host individuals and host populations, and how such effects impact the evolution of their hosts. Some of the topics we currently investigate are:

  • Context-dependent outcomes in trematode/fish and virus/amphibian interactions
  • Altered behaviour in trematode-infected ants and minnows
  • Ecology of multi-parasitism
  • Behavioural defenses of hosts to parasitism
  • Population genetic structure of larval and adult Dicrocoelium
  • Evolution and phylogeny of the trematode genus, Ornithodiplostomum
  • Feeding and encystment strategies of larval trematodes
  • Ecology and evolution of the monogenean trematode, Gyrodactylus olfactorius (n. sp.) in minnows

Applied parasitology – I am interested in where and when domestic animals that graze on pasture are most at risk of infection with gastro-intestinal worms. A further focus is to clarify the production costs associated with infection. Our overall aim is to provide information to producers that will help them develop optimal treatment regimes for the control of worms. We combine experiments involving experimentally-infected hosts, development of immuno-diagnostic tools, application of geographical information systems, and standard host surveys to answer the following questions:

  • How are parasites transmitted within communities of grazing animals that share pasture?
  • Where and when are cattle most at risk of infection with worms in Alberta?
  • Do larvae of common worms in cattle overwinter on Alberta pastures?
  • Can worm antigens that are present in host feces be used to identify ‘wormy’ individuals in a herd?

Ecology of emerging parasites and pathogens –  Emerging pathogens and parasites are recognized as important threats to global biodiversity. We have a poor understanding of how these emerging parasites and pathogens enter populations of wild and domestic hosts in Alberta. Furthermore, we have a poor understanding of their consequences for new host populations, and we rarely understand the factors that promote or constrain their subsequent spread into novel areas and novel hosts. Current areas of emphasis are:

  • Landscape epidemiology of invasive lancet liver fluke in ants and snails in Alberta
  • Ecological epidemiology of an emerging virus (ATV) in endangered populations of blotched tiger salamander in Alberta
  • Enemy-release and parasitism of the invasive snail, Radix auricularia, in southern Alberta wetlands

Prairie biodiversity and conservation ­– The landscape in Southern Alberta comprises a mosaic of habitats that are dominated by short- and mixed-grass prairie that is characteristic of the Northern Great Plains. The natural history of the region is spectacular for its biodiversity. Our focus lies in determining key demographic characteristics of poorly-known animal taxa that are potentially threatened in this region:

  • Oreohelid land snails, especially O. cooperi and Oreohelix sp. that may be endemic to the Cypress Hills region of Southeastern Alberta
  • Unionid clams, particularly within biodiversity hotspots in the Battle River in central Alberta, and its tributaries
  • Blotched tiger salamander, Ambystoma mavortium, in foothills habitats where emerging Ambystoma tigrinum virus (ATV) is common
  • Long-toed salamander, Ambystoma macrodactylum, in foothills and montane regions of the northern Rocky Mountains