Research (I am not accepting graduate students now)

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• Ongoing research:
  • 1. Epigenetic changes, maternal effects, stress, and the role of sublethal effects of high predation risk on snowshoe hares.
  • The enigma of the 10-year snowshoe hare cycle - the low phase that lasts for 2-4 years and follows the decline phase - remains. The predators have almost all died, the vegetation has recovered, yet the hare population fails to recover immediately. Based on our initial work on the stress effects of high predation risk (See Boonstra et al. 1998 Ecological Monographs 68:371-394; Ecology 79:1479-1488) and the recent findings of Sheriff, Krebs, and Boonstra (see references  below), the most plausible hypothesis is that intergenerational programming operating through maternal effects is occurring and is likely epigenetic. See the elegant epigenetic research on the stress axis carried out by M. Meaney and M. Szyf (see Weaver et al. 2004 Nature Neuroscience 7:847-854). This is strengthen by findings of P. McGowan et al. (2009 Nature Neuroscience 12:342-348) in humans indicate the profound impact of severe stress on epigenetic changes in the genome. This research is currently being addressed by Sophia Lavergne. It takes place in the Yukon, and involves a close marriage of field ecology, physiology (neuroendocrinology) and genetics
  • 2. Epigenetic changes, maternal effects, and population regulation in voles and lemmings.
  • 3. Snowshoe hare predation risk.

  • Snowshoe hares have been studied for 30+ years in our southwestern Yukon study site. A recent studies by Sherriff et al. (2009 J. Anim. Ecol. 78:1249-1258, 2010 Ecology 91:2983-2994, and 2011 Oecologia 166:593-605) found that a predator-induced increase in baseline stress levels affected the reproductive rates of hares, with highly-stressed  females producing fewer litters of young and generally smaller and less robust leverets. These findings imply that predators may have important sublethal effects on snowshoe hares, which could translate to predators  having an even more important role than previously thought on the snowshoe hare population cycle. Aspects of this research is being addressed by 3 PhD students (2 co-supervised) and a cosupervised MSc. student. The research builds on the previous study and assesses whether sublethal effects of predators have demonstrable effects on hare behaviour and survival. Using a variety of methods, we are monitoring relationships between hare food, hare activity patterns, habitat selection, energy expenditure, and survival rates, relative to baseline stress levels. We predict that individual variability in stress levels will reflect local predation risk, and thereby be manifest in risk-sensitive behaviour among putative high-risk individuals. The intent is to follow up the observational study with experimental manipulation of perceived risk to induce further changes in free-ranging hares. Finally, the study will involve modeling tradeoffs between energy acquisition versus predation risk avoidance, and possibly include modeling the potential sublethal effects of predators on hare population cycles.

  • Four collaborators are key to this research - Dr. Stan Boutin (Univ. Alberta), Dr. Murray Humphries (McGill), Dr. Charles Krebs (UBC), and Dr. Dennis Murray (Univ. Trent).