title: Experimental evidence for the effect of habitat loss on the dynamics of migratory networks.
abstract: Migratory animals present a unique challenge for understanding the consequences of habitat loss on population dynamics because individuals are typically distributed over a series of interconnected breeding and non-breeding sites (termed migratory network). Using replicated breeding and non-breeding populations of Drosophila melanogaster and a mathematical model, we investigated three hypotheses to explain how habitat loss influenced the dynamics of populations in networks with different degrees of connectivity between breeding and non-breeding seasons. We found that habitat loss increased the degree of connectivity in the network and influenced population size at sites that were not directly connected to the site where habitat loss occurred. However, connected networks only buffered global population declines at high levels of habitat loss. Our results demonstrate why knowledge of the patterns of connectivity across a species range is critical for predicting the effects of environmental change and provide empirical evidence for why connected migratory networks are commonly found in nature.
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
authors.forename: Gustavo S
authors.initials: GS
authors.lastname: Betini
authors.affiliation: Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, M1C 1A4, Canada.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Fitzpatrick
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
authors.forename: D Ryan
authors.initials: DR
authors.lastname: Norris
mesh_terms: D025041:Animal Migration; D000818:Animals; D001947:Breeding; D003198:Computer Simulation; D003247:Conservation of Natural Resources; D004331:Drosophila melanogaster / Q000502:physiology*; D017753:Ecosystem; D008962:Models, Theoretical; D011156:Population Density; D011157:Population Dynamics
keywords: Climate change; Drosophila melanogaster; graph theory; migratory connectivity