Supplement 1. Pascal program for computing the residence time.

File List Residence_time.txt -- PASCAL CODE Description This program can run with any Pascal compiler (a free compiler working on most operating systems can be downloaded at www.freepascal.org). It works from an input file in plain text where the two first columns are Cartesian coordinates (<em>x</em>, <em>y</em>) of the successive locations, and the third column is the associated time <em>t</em>. Georeferenced data (i.e., expressed in latitudeand longitude) must be first converted in Cartesian coordinates, by using an appropriate projection system. Nevertheless, if the movement was restricted to a relatively small area (a few degrees in both latitude and longitude) that is not too close to the poles (i.e., below 70°N and above 70°S), approximate but reliable Cartesian coordinates, expressed in km, can be obtained from latitude, <em>lat</em>, and longitude, <em>long</em>, expressed in degrees, as: <em>x</em> = 111.12 (<em>long</em> - <em>long0</em>) cos(<em>lat0</em> -- IMAGE: Please see in attached file. --/180), <em>y</em> = 111.12 (<em>lat</em> - <em>lat0</em>), where <em>lat0</em> and <em>long0</em> are the latitude and the longitude of the first location. The name of the input and output files should include the whole directory path (e.g., C:\data\input_file.txt on a DOS or Windows operating system). The radius of the virtual circle and the step length (if the movement should be spatially rediscretized) must be expressed in the same unit as Cartesian coordinates <em>x</em> and <em>y</em>; the step duration (if the movement should be temporally rediscretized) must be expressed in the same unit as time <em>t</em>.