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Generalized linear models for means and variances applied to movement of tiger beetles along corridor roads
Author(s) -
Van Dooren Tom J. M.,
Matthysen E.
Publication year - 2004
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.0021-8790.2004.00804.x
Subject(s) - range (aeronautics) , statistics , movement (music) , variance (accounting) , advection , mathematics , linear regression , ecology , environmental science , econometrics , biology , materials science , physics , accounting , business , composite material , thermodynamics , philosophy , aesthetics
Summary1 Movement is often conditional on environmental parameters and behavioural phenotype. A reasonable assumption is that individuals behave as random walkers, when environment and behaviour are fixed. 2 Based on this assumption, observations of movements can be analysed with a set of generalized linear models. Such models can predict the occurrence of behaviour and movement distance distributions resulting from different behavioural or environmental parameters. 3 This method was applied to study short‐range movement of tiger beetles ( Cicindela hybrida ) along corridor roads. 4 Logistic regression was used to estimate probabilities of behaviour types occurring during 5‐min observation intervals. 5 Movement distances were investigated with a pair of generalized regression models for both the mean and the variance of the distances covered during observations. The models estimate mean and variance of a normal distribution per set of environmental conditions and per combination of behaviour types observed in the observation interval. 6 Flying behaviour, the number of interactions with other beetles and the amount of food items handled differed between spring and summer season. 7 Advective movement was demonstrated, and it occurred in the direction of the sun. The advection effect is more pronounced when beetles fly. We propose that this advection occurs as a side effect of thermoregulatory behaviour. 8 Diffusion or spread of displacements increased with the occurrence of flying and decreased when beetles spent time sheltering in shade or handling food. 9 Simulations were used to generate movement distributions over longer time spans, assuming that the selected model applies per time step. Such distributions can be used to generate null hypotheses for different types of experiments, and for extrapolation. 10 The simulations show that only when there is little advection do distance distributions remain normal. Mean predicted displacement distances reach up to around 100 meter after 2 h.