The nearest and next-to-nearest neighbour spacings between buzzard nests in the Teutoburger Wald around Bielefeld, as gathered in the years2000--2019, are compared with Ginibre random matrix ensembles as well as the Poisson spacing distributionin two dimensions. Our goal is a phenomenological description of some structural aspects in the territorial behaviour of these birds. To capture intermediate spacings between Ginibre and Poisson, we also compare to numerically generated two-dimensional Coulomb gases at different temperatures, which interpolate between the two. We find a stronger repulsion between nearest neighbours than between next-to-nearest ones, for more than the first half of the observed period. The increase of the absolute density of nests observed in that area over the monitored period of time leads to an increase of repulsion among neighbouring nests. Central to our approach is the use of well-established ideas from universal spatial structures, which suggest to employ a family of interpolating distributions with only one free parameter that parametrises the repulsionand that correlates well with the concepts from population ecology.
A deeper understanding of the processes underlying the distribution of animals in space is crucial for both basic and applied ecology. The Common buzzard (Buteo buteo) is a highly aggressive, territorial bird of prey that interacts strongly with its intra- and interspecific competitors. We propose and use random matrix theory to quantify the strength and range of repulsion as a function of the buzzard population density, thus providing a novel approach to model density dependence. As an indicator of territorial behaviour, we perform a large-scale analysis of the distribution of buzzard nests in an area of 300 square kilometres around the Teutoburger Wald , Germany, as gathered over a period of 20 years. The nearest and next-to-nearest neighbour spacing distribution between nests is compared to the two-dimensional Poisson distribution, originating from uncorrelated random variables, to the complex eigenvalues of random matrices, which are strongly correlated, and to a two-dimensional Coulomb gas interpolating between these two. A one-parameter fit to a time-moving average reveals a significant increase of repulsion between neighbouring nests, as a function of the observed increase in absolute population density over the monitored period of time , thereby proving an unexpected yet simple model for density-dependent spacing of predator territories. A similar effect is obtained for next-to-nearest neighbours, albeit with weaker repulsion, indicating a short-range interaction. Our results show that random matrix theory might be useful in the context of population ecology.
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The nearest and next-to-nearest neighbour spacings between buzzard nests in
A deeper understanding of the processes underlying the distribution of animals in space is crucial for both basic and applied ecology. The Common buzzard (Buteo buteo) is a highly aggressive, territorial bird of prey that interacts strongly with its intra- and interspecific competitors. We propose and use random matrix theory to quantify the strength and range of repulsion as a function of the buzzard population density, thus providing a novel approach to model density dependence. As an indicator of territorial behaviour, we perform a large-scale analysis of the distribution of buzzard nests in an area of 300 square kilometres around
R
around Bielefeld, as gathered in the years2000--2019, are compared with Ginibre random matrix ensembles as well as the Poisson spacing distributionin two dimensions. Our goal is a phenomenological description of some structural aspects in the territorial behaviour of these birds. To capture intermediate spacings between Ginibre and Poisson, we also compare to numerically generated
, Germany, as gathered over a period of 20 years. The nearest and next-to-nearest neighbour spacing distribution between nests is compared to the two-dimensional Poisson distribution, originating from uncorrelated random variables, to the complex eigenvalues of random matrices, which are strongly correlated, and to a
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gases at different temperatures, which interpolate between the two. We find a stronger repulsion between nearest neighbours than between next-to-nearest ones, for more than the first half
gas interpolating between these two. A one-parameter fit to a time-moving average reveals a significant increase of repulsion between neighbouring nests, as a function
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period. The increase of the absolute density of nests observed in that area
increase in absolute population density
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leads to an increase of repulsion among neighbouring nests. Central to our approach is the use of well-established ideas from universal spatial structures, which suggest to employ a family of interpolating distributions with only one free parameter that parametrises the repulsionand that correlates well with the concepts from
, thereby proving an unexpected yet simple model for density-dependent spacing of predator territories. A similar effect is obtained for next-to-nearest neighbours, albeit with weaker repulsion, indicating a short-range interaction. Our results show that random matrix theory might be useful in the context of