Supplement 1. Annotated INLA code for the model with snow cover extent from 1967–2010.

<h2>File List</h2><div> <p><a href="INLA_code.R">INLA_code.R</a> (MD5: 68c372169a851d7616d30172ce203f50)</p> <p><a href="ss_model_inla.csv">ss_model_inla.csv</a> (MD5: 3b3bf472211df425134b22e33dbac549)</p> </div><h2>Description</h2><div> <p>INLA_code.R is an R script file to analyze scaup pair abundance using a Gompertz state-space model containing a covariate for snow cover extent. This script assumes that the INLA package has been downloaded from <a href="http://www.r-inla.org">http://www.r-inla.org</a>. The data set (ss_model_inla.csv) should be in the working directory when running this code.</p> <p>ss_model_inla.csv is a comma-separated text file containing the scaup dataset. Column definitions are:</p> <ol> <li>y: counts from each stratum in each year from BPOP aerial survey</li> <li>stratum: each stratum number, adjusted for analysis in INLA, where ‘1’ = Stratum 13 as defined by the BPOP survey, ‘2’ = Stratum 14, ‘3’ = Stratum 15, ‘4’ = Stratum 16, ‘5’ = Stratum 17, and ‘6’ = Stratum 18</li> <li>year: year since beginning of survey (1955)</li> <li>stand.snow: standardized covariate for snow cover extent</li> <li>N: number of segments flown in each stratum each year</li> </ol> </div>