I maintain a strong interdisciplinary framework to address theoretical and applied questions at the interface of population, community and behavioural ecology. I take a multi-scale dynamic systems approach to investigate the role of top predators in arctic sea ice ecosystems, where unique landscape structure and temporal processes allow conducting non-invasive natural experiments.

As a part of this process, I develop novel data acquisition and analytical techniques to model, quantify and describe patterns of behaviour, distribution and population dynamics in relation to community and ecosystem processes. I am particularly interested in understanding interactions between processes that occur at different rates or spatiotemporal scales. I apply my research to general paradigms in ecology and to issues of conservation and management concern. I work closely with wildlife managers and northern communities. I also place a major emphasis on education and outreach, using the multi-media techniques and capacity developed through my research program.

My primary research program currently focuses on the winter ecology of sea ice habitats, particularly the Hudson Bay Common Eider Somateria mollissima sedentaria, a diving sea duck that over-winters in the arctic, instead of migrating south. The population is structured in groups of various sizes and age structures that move between different polynya, floe edge and dynamic pack ice habitats. Eiders seek productive open waters to dive for benthic invertebrates. Within these habitats, eiders have a major influence on the structure of benthic communities and can often deplete local prey resources. Habitats differ in their predictability, prey availability and oceanographic characteristics. While currents are periodic over tidal and lunar time scales, stochastic environmental conditions can quickly shift sea ice landscape structure. Eiders must adjust their habitat and foraging decisions in response to this variation, to obtain adequate energy to survive the harsh arctic winter. To understand the factors influencing winter survival and population dynamics, I take an integrative approach, incorporating the role of locomotion, physiology and foraging behaviour into empirically based bio-energetic and dynamic systems models. I use this approach to investigate relationships between community ecology within habitats, and larger scale population structure and dynamics. This quantitative multi-scale approach is used to understand how sea ice ecosystems in Hudson Bay respond to changing environmental variation.

Specific Research Questions:
1) How do currents and sea ice dynamics influence the ability of eiders to obtain adequate energy for winter survival?
2) How do social interactions (interference, facilitation) influence aggregation, distribution and spatial community ecology in sea ice habitats?
3) How are benthic invertebrate communities structured by eiders, and to what extent can these communities support eider populations and recover from depletion?
4) How can foraging behaviour be used to determine functional and numerical responses that influence population dynamics and food web structure, and how are these influenced by environmental change in sea ice habitats?

This research program is conducted in collaboration with the Canadian Wildlife Service, the Nunavut Wildlife Management Board, the community of Sanikiluaq and International Polar Year. Selected Publications on this topic: J. P. Heath, H.G. Gilchrist & R.C. Ydenberg (Sept 10, 2010; Cover Feature). Interactions between rate processes with different time scales explain counterintuitive foraging patterns of arctic wintering eiders. Proc. Roy. Soc. B J. P. Heath & H.G. Gilchrist (2010). When foraging becomes unprofitable: energetics of diving in tidal currents by common eiders wintering in the Arctic. Marine Ecology Progress Series 403:279-290. Heath, J.P., Gilchrist, H.G., and Ydenberg, R.C. (2007). Can diving models predict patterns of foraging behaviour? Diving by Common Eiders in an arctic polynya. Animal Behaviour 73:877-884. Heath, J.P., Gilchrist, H.G. and Ydenberg, R.C. (2006). Regulation of stroke patterns and swim speed across a range of current velocities: diving by Common Eiders wintering in polynyas in the Canadian arctic. Journal of Experimental Biology 209, 3974-3983. My ongoing education and outreach initatives, the People of a Feather film project and The Arctic Sea Ice educational package recently received funding as one of Canada's largest International Polar Year projects for training, communications and outreach. Think outside the bell... what is 'normal' when it comes to measuring variability? Originally conceived as a way to measure variability in population abundances, without assuming populations were undergoing 'normal' (Guassian) dynamics, this metric has resolved many major issues, including that of 'rare events', a major complication in population biology. It also allows more accurate estimation of long term variability from short term data sets, and is presently being developed as a more general replacement for the coefficient of variation in other disciplines. Heath, J.P. (2006). Quantifying temporal variability in population abundances. Oikos 115:573-581.