We define as H 0 the model where b M~b 0 M and b F~b 0 F , the four model parameters (b 0 M , b 0 F , e M and e F ) being positive. As a general definition, models involving other parameters are called H(l), where l denotes the set of free (non-zero) parameters in the model that are notb 0 M , b 0 F , e M and e F . Then we investigate the possibility that, all other parameters being equal, the external transmission rates (e M and e F ) may differ between cat populations due to their spatial organization. Indeed, behavioral observations suggest a network of contacts between the different populations (see Fig. 1 , solid arrows), which can be simplified by dividing the study area into three distinct metapopulations (see Fig. 1 , grey areas). Since we do not model spatial structure explicitly, we assume that connectivity between populations affects external transmission rate. We define the resulting ''neighboring'' models and ''metapopulation'' models as follows.