Generalized spatial mark-resight models with an application to grizzly bears

1. The high cost associated with capture-recapture studies presents a major challenge when monitoring and managing wildlife populations. Recently-developed spatial mark-resight (SMR) models were proposed as a cost-effective alternative because they only require a single marking event. However, existing SMR models ignore the marking process and make the tenuous assumption that marked and unmarked populations have the same encounter probabilities. This assumption will be violated in most situations because the marking process results in different spatial distributions of marked and unmarked animals. 2. We developed a generalized SMR model that includes sub-models for the marking and resighting processes, thereby relaxing the assumption that marked and unmarked populations have the same spatial distributions and encounter probabilities. 3. Our simulation study demonstrated that conventional SMR models produce biased density estimates with low credible interval coverage when marked and ...