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Rotifer population spread in relation to food, density and predation risk in an experimental system
Author(s) -
Kuefler Daniel,
Avgar Tal,
Fryxell John M.
Publication year - 2012
Publication title -
journal of animal ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.134
H-Index - 157
eISSN - 1365-2656
pISSN - 0021-8790
DOI - 10.1111/j.1365-2656.2011.01917.x
Subject(s) - rotifer , predation , brachionus calyciflorus , biology , population density , density dependence , population , ecology , predator , replicate , range (aeronautics) , statistics , demography , mathematics , materials science , composite material , sociology
Summary 1. Despite the popular use of diffusion models to predict the spatial spread of populations over time, we currently know little about how diffusion rates change with the state of the environment or the internal condition of individuals. To address this gap in our understanding, we measured rates of spread for many populations of the rotifer Brachionus calyciflorus in a suite of well‐replicated experiments. 2. In one set of experiments, we manipulated food availability and population density along a continuous range of densities. In a second set, we manipulated the internal state of entire populations via food deprivation and exposure to predator kairomones. 3. Across replicate populations, diffusion rates were positively correlated with conspecific density. Diffusion rates were negatively correlated with food availability, especially when conspecific density was high. Diffusion rates of food‐deprived populations or those exposed to predation risk were lower than controls. 4. Our results provide direct experimental evidence that rates of population spread are conditional on population density, food availability, body condition and predation risk.