Robby Marrotte

McGill University
M.Sc. candidate

Supervisor: Virginie Millien
Andrew Gonzalez
Start: 2011-09-01
End: 2013-04-15
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Connectivity and habitat use by Peromyscus leucopus in a fragmented landscape in Southern Quebec
The range of the white-footed mouse has expanded into Southern Québec over the last few decades, while its abundance has increased in forest patches within the Montérégie region, QC. The genetic structure of white-footed mouse populations in this region is known to be affected by geographical distance and rivers. Here we evaluated the relations between forest habitat, matrix resistance and network, against the genetic differentiation between populations. Eleven forest patch habitats were characterised by 18 variables that were correlated with genetic differentiation. The resistance of the matrix to dispersal was evaluated by finding the best fit between the genetic data and resistance surfaces. Resistance values were assigned to land use classes, maximizing the mantel correlation between ecological and genetic variability. The importance of the forest patch network was assessed for a range of distance thresholds to capture the mouse’s dispersal ability. Litter depth, maximum tree width and ground cover significantly explained the genetic differentiation of the populations while the matrix caused resistance to gene flow. The urban land cover class increases the genetic differentiation more effectively than all other classes, including water and agriculture. Forest patch networks matched genetic differentiation for dispersal thresholds between 800 and 1200 meters. Both within and between forest patches factors have been found to have more of an impact on genetic differentiation than the geographical distance between the mice populations, suggesting that this species can disperse and use a wide range of habitats. This is in accordance with its recent rapid expansion in the region.


landscape genetics, landscape genetics, landscape resistance, gene flow, white-footed mouse, Peromyscus leucopus


1- The utility of Nymphaeaceae sclereids in paleoenvironmental research
Marrotte, Robby R., Gail L. Chmura, Peter A. Stone
2012 Review of Palaeobotany and Palynology