Supplement 1. WinBUGS code for model .

File List spatial_dep_model.txt -- WinBugs model definition file spatial_dep_script.txt -- WinBugs script file spatial_dep_data.txt -- Sample data file Description Input data consists of the matrix hij, the detection/nondetectin data for site i, survey j. In the code, zi denotes presence (zi =1) or absence (zi=0) at the level of the sample unit, i; yij denotes local presence (yij = 1) or absence (yij = 0) on segment j; and hij denotes detection (hij =1) or not (hij =0) on segment j of sample unit i. Each of these random variables is modeled as a Bernoulli trial, the latter two conditional on occupancy at sample unit and segment scale: All model parameters were given uniform prior distributions, U(0,1). -- IMAGE: Please see in attached file. --