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2009-01-01

Derocher, Andrew E., Klanjscek, Tin, Molnár, Péter K., Lewis, Mark A., Obbard, Martyn E.

Many species experience large fluctuations in food availability and depend on energy from fat and protein stores for survival, reproduction and growth. Body condition and, more specifically, energy stores thus constitute key variables in the life history of many species. Several indices exist to...

2015-01-01

Jonathan R. Potts, Mark A. Lewis

Territoriality is a phenomenon exhibited throughout nature. On the individual level, it is the processes by which organisms exclude others of the same species from certain parts of space. On the population level, it is the segregation of space into separate areas, each used by subsections of the...

2019-01-01

Fazly, Mostafa, Lewis, Mark A, Wang, Hao

We study a hybrid impulsive reaction-advection-diffusion model given by a reaction-advection-diffusion equation composed with a discrete-time map in space dimension $n\in\mathbb N$. The reaction-advection-diffusion equation takes the form \begin{equation}\label{} u^{(m)}_t = \text{div}(A\nabla...

2016-01-01

Jonathan R. Potts, Mark A. Lewis

Mechanistic home range analysis (MHRA) is a highly effective tool for understanding spacing patterns of animal populations. It has hitherto focused on populations where animals defend their territories by communicating indirectly, e.g. via scent marks. However, many animal populations defend...

2017-01-01

QIHUA HUANG, HAO WANG, MARK A. LEWIS

While some species spread upstream in river environments, not all invasive species are successful in spreading upriver. Here the dynamics of unidirectional water flow found in rivers can play a role in determining invasion success. We develop a continuous-discrete hybrid benthic-drift population...

2002-01-01

Lewis, Mark A., Bingtuan Li, Hans F. Weinberger

 One crucial measure of a species' invasiveness is the rate at which it spreads into a competitor's environment. A heuristic spread rate formula for a spatially explicit, two-species competition model relies on `linear determinacy' which equates spread rate in the full nonlinear model with spread...

1992

Kouritzin, Michael, Heunis, A.J.

Let μ be a positive finite Borel measure on the real line R. For t ≥ 0 let et · E1 and E2 denote, respectively, the linear spans in L2(R, μ) of {eisx, s > t} and {eisx, s < 0}. Let θ: R → C such that ∥θ∥ = 1, denote by αt(θ, μ) the angle between θ · et · E1 and E2. The problems considered here...

2023-09-27

Brush, Micah, Lewis, Mark A.

Mountain pine beetle (MPB) in Canada have spread well beyond their historical range. Accurate modelling of the long-term dynamics of MPB is critical for assessing the risk of further expansion and informing management strategies, particularly in the context of climate change and variable forest...

1995-01-01

Sherratt, J. A., Lewis, Mark A., Fowler, A. C.

Irregularities in observed population densities have traditionally been attributed to discretization of the underlying dynamics. We propose an alternative explanation by demonstrating the evolution of spatiotemporal chaos in reaction-diffusion models for predator-prey interactions. The chaos is...

2017-04-01

Guillaume Bastille-Rousseau, Dennis L. Murray, James A. Schaefer, Mark A. Lewis, Shane P. Mahoney, Jonathan R. Potts

Movement influences a myriad of ecological processes operating at multiple spatial and temporal scales. Yet our understanding of animal movement is limited by the resolution of data that can be obtained from individuals. Traditional approaches implicitly assume that movement decisions are made at...