A two‐species occupancy model accommodating simultaneous spatial and interspecific dependence

Abstract

. Occupancy models are popular for estimating the probability a site is occupied by a species of interest when detection is imperfect. Occupancy models have been extended to account for interacting species and spatial dependence but cannot presently allow both factors to act simultaneously. We propose a two-species occupancy model that accommodates both interspecifi c and spatial dependence. We use a point-referenced multivariate hierarchical spatial model to account for both spatial and interspecifi c dependence. We model spatial random effects with predictive process models and use probit regression to improve effi ciency of posterior sampling. We model occupancy probabilities of red fox ( Vulpes vulpes ) and coyote ( Canis latrans ) with camera trap data collected from six midAtlantic states in the eastern United States. We fi t four models comprising a fully factorial combination of spatial and interspecifi c dependence to two-thirds of camera trapping sites and validated models with the remaining data. Red fox and coyotes each exhibited spatial dependence at distances >0.8 and 0.4 km, respectively, and exhibited geographic variation in interspecifi c dependence. Consequently, predictions from the model assuming simultaneous spatial and interspecifi c dependence best matched test data observations. This application highlights the utility of simultaneously accounting for spatial and interspecifi c dependence.

A multispecies occupancy model for two or more interacting species

“…; Rota et al . ). See Appendix S2 for a description of a multivariate probit regression model and details for constructing a Gibbs sampler.…”

“…The assumption of independence between sites is unlikely to hold exactly for this data set (Rota et al . ), though accounting for spatial dependence when modelling >2 species is still an open research problem. Cameras were attached to trees 40 cm above the ground and were deployed for 1–71 (mean = 22) consecutive days between August 2012 and December 2013.…”

A multistate dynamic occupancy model to estimate local colonization–extinction rates and patterns of co‐occurrence between two or more interacting species

“…Although Rota, Wikle, et al. () relax this assumption with a two species occupancy model, the question remains whether such an approach can be generalized to >2 species or through time.…”

An occupancy approach to monitoring regent honeyeaters

“…In addition, specialist species that form breeding aggregations often show spatial autocorrelation in their occupancy data, where monitoring sites are not spatially independent in terms of their habitat attributes or probability of occupancy (Webb et al , Bardos et al ). Modeling approaches must therefore account for imperfect detection and spatial dependence to make robust inferences about a species' ecology from occupancy data (Hui et al , Rota et al ). Failure to account for either phenomena can bias occupancy estimates (Olson et al , Banks‐Leite et al ) and false absences (failing to detect a species when present) may inhibit capacity to identify changes in the size of small populations (Jones , Ferguson et al ) and compromise understanding of habitat selection (Gu and Swihart ), potentially limiting the effectiveness of management actions (Baxter and Possingham , Gilroy et al ).…”