Resource Selection Functions allow knowing which habitat characteristics are preferred by a species. To determine them, two types of locations are considered: a set of locations in which the animal has been recorded (usually through GPS), which are called “used locations”, and a set of “available locations” where the individual has not been observed. The latter are usually sampled uniformly over the animal home range. The thesis aims to construct Bayesian Hierarchical models for use-availability data of two animals that are modeled jointly. We formalized four models and, through a simulation study, we evaluated the identifiability of the parameters and the convergence of the model with respect to the number of available locations.