Table of Contents

Geoffrey Legault
Postdoctoral Fellow, Wolkovich Group
Forest and Conservation Science, University of British Columbia

Hello! I am interested in a variety of topics in the fields of ecology and evolutionary biology, including: range expansion, phenology, coexistence, synchrony, and life history. To answer questions in these areas, I use mathematical models to make predictions about what is possible. I also try to link the possible with the actual by fitting models to data.

I am particularly interested in applications of stochastic models, as they can account for unknown or unmeasured sources of variation, both of which are common in biological systems. Read more about my research by scrolling down or clicking here.


Curriculum vitae

Google scholar profile | ORCID profile

You can download my CV here (updated 2020-12-30)


Range expansion

The geographic ranges of many species are shifting as a result of climate change and human introductions. Theoretical models show that competitive interactions have the potential to affect the speed and shape of these expansions. However, competitive interactions are rarely considered when forecasting expansion in nature.

I combine experimental microcosms of flour beetles (Tribolium castaneum and Tribolium confusum) with stochastic spatiotemporal models to more clearly link theory with nature.

Recent work in this system (Legault et al. 2020) found: (1) Competition slows range expansion and (2) Competition continually changes the shape of the expanding range boundary. Both findings support greater consideration of competitive interactions when forecasting range expansion.


Figure 1: Experimental data showing the impact of interspecific competition on range expansion across 8 generations. Lines are mean abundances across 16 patch landscapes (15 replicates). Shaded areas are 95% confidence intervals for generation 8.


Figure 2: Fit of a stochastic growth model for Tribolium castaneum (left) and Tribolium confusum (right). Points are experimental data and slices show parts of the three-dimensional probability volume of the fitted model (warmer colors = higher probability). N is abundance of T. castaneum and M is abundance of T. confusum.

Winegrape phenology

Phenology, the timing of biological events, is a key determinant of lifetime fitness, species interactions, and ecosystem functioning. Using winegrapes as a model system, I am developing stochastic models of phenology that can be applied to a variety of systems and spatial scales.

winegrape.jpg vines_heatwave.jpg


Figure 3: Conceptual diagram of a phenology model where the distribution of occurrence times changes with environment.

Life history trade-offs

Life history traits (e.g., maturation time, mass at maturity) frequently co-vary and exhibit important trade-offs. Characterizing such trade-offs is necessary for predicting lifetime fitness and optimal evolutionary strategies. I develop stochastic models of life history traits and validate them with data, in order to better understand how these trade-offs manifest in natural systems.

During my postdoc with Joel Kingsolver, I created a continuous-time stochastic model describing the joint distribution of an insect's age and mass at maturity. The model is based on the developmental biology of Manduca sexta, and predicts novel trade-offs between age and mass at maturity. You can read about the model here.

I am currently working to validate this model with data from laboratory experiments.

devmass_model.png devmass_sensitivity.png



  1. Legault, G, Bitters, M. E., Hastings, A., Melbourne, B. A. (2020) Interspecific competition slows range expansion and shapes range boundaries. Proceedings of the National Academy of Sciences of the United States of America. 117(43): 26854-26860 link data
  2. Legault, G., Kingsolver, J. (2020) A stochastic model for predicting age and mass at maturity of insects. The American Naturalist. 196: 227-240 link data
  1. Bullock, M., Legault, G., Melbourne, B. A. (2020) Interspecific chemical competition between Tribolium castaneum and Tribolium confusum reduces fecundity and hastens development time. Annals of the Entomological Society of America 113(3): 216-222 link


  1. Legault, G., Fox, J., Melbourne, B. A. (2019) Demographic stochasticity alters expected outcomes in experimental and simulated non‚Äźneutral communities. Oikos 128(12): 1704-1715 link data
  1. Legault, G., Melbourne, B. A. (2019) Accounting for environmental change in continuous-time stochastic population models. Theoretical Ecology 12(1): 31-48 link
    • Recommended ("Very Good") by Faculty of 1000 Prime Access the recommendation on F1000Prime

2018 and before

  1. Contributing author (2018) "Direct and indirect drivers of land degradation and restoration" in Assessment Report on Land Degradation and Restoration. Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) link
  1. Legault, G., Cusa, M. (2015) Temperature and delayed snowmelt jointly affect the vegetative and reproductive phenologies of four sub-Arctic plants. Polar Biology 38: 1701-1711 link
  1. Fox, J., Legault, G., Vasseur, D., Einarson, J. (2013) Nonlinear effect of dispersal rate on spatial synchrony of predator-prey cycles. PLoS ONE 8(11): e379527 link
  1. Legault, G., Weis, A. (2013) The impact of snow accumulation on a heath spider community in a sub-Arctic landscape. Polar Biology 36: 885-894 link


  • T. Dallas, B.A. Melbourne, G. Legault, A. Hastings. Initial abundance and stochasticity influence competitive outcome in communities.




I do many of my tasks (e.g., R coding, writing, tracking RSS feeds, this website) within the venerable text editor Emacs. If you're interested in learning about it, here's a basic introduction.