Measures of niche overlap in Ecology
In Ecology, the niche of a species is usually defined as a multidimensional hyper-volume in which a species maintains a viable population (Hutchinson 1957). The community structure may be shaped by resource partitioning between co-occurring species, so quantifying the degree of this partitioning (i.e. niche overlap) is very important when studying species co-existence (Geange et al. 2010). The niche space is often described by multiple axes or variables. When all such axes describe continuous measurements, the niche overlap may be quantified using a measure of similarity of two probability density functions, and is often estimated using non-parametric methods. Here we discuss a Bayesian approach to this problem based on Gaussian Dirichlet process mixture models. We also propose a simple exploratory --but more flexible-- measure of niche overlap. Both ideas are illustrated with real data concerning three mammalian species inhabiting the 'El Triunfo' Biosphere Reserve in Chiapas, Mexico.
* Joint work with M. Mendoza, A. Contreras and E. Mendoza