Supplement 1. WinBUGS code for model .

File List spatial_dep_model.txt -- WinBugs model definition file <br> spatial_dep_script.txt -- WinBugs script file <br> spatial_dep_data.txt -- Sample data file Description Input data consists of the matrix <i>h_ij</i>, the detection/nondetectin data for site <i>i</i>, survey <i>j</i>. In the code, <i>z_i</i> denotes presence (<i>z_i</i> =1) or absence (<i>z_i</i>=0) at the level of the sample unit, <i>i</i>; <i>y_ij</i> denotes local presence (<i>y_ij</i> = 1) or absence (<i>y_ij</i> = 0) on segment <i>j</i>; and <i>h_ij</i> denotes detection (<i>h_ij</i> =1) or not (<i>h_ij</i> =0) on segment <i>j</i> of sample unit <i>i</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. --