Spatial Modeling of Habitat Preferences of Biological Species using Markov Random Fields

Spatial modeling has gained interest in ecology during the past two decades, especially in the area of biodiversity, where reliable distribution maps are required. Several methods have been proposed to construct distribution maps, most of them acknowledging the presence of spatial interactions. In many cases, a key problem is the lack of true absence data. We present here a model suitable for use when true absence data are missing. The quality of the estimates obtained from the model is evaluated using ROC curve analysis as well as a quadratic cost function, computed from the false positive and false negative error rates. The model is also tested under random and clustered scattering of the presence records. We also present an application of the model to the construction of distribution maps of two endemic bird species in México.