We developed a binary Markov Random Field (a.k.a. Ising Model) based spatial explicit multispecies occupancy model to analyze camera trap data of Apostle Island national lake shore. We mainly focused on fisher-marten and coyote-fox system. Special MCMC algorithm was developed to fit the model (available here). Results showed that fisher-marten seemed to have an opposite mainland-island source-sink pattern whose competition was minor, while coyote-fox has some positive interspecific interaction may caused by bottom up control.