Setting the Spatial Threshold:

Spatial threshold refers to the maximum distance two individuals can be found from one another and still be considered associated at that moment in time. Any pair of individuals found at a distance that exceeds the spatial threshold will be considered non-associated by Association Software.

As an example, if the spatial threshold has been set to 500 units (the units are the same units used in your input location file's X and Y fields) and the distance between individual A and individual B on June 1 is 250 units, then individual A and individual B will be considered associated on this date. If the distance between individual A and individual C on June 1 is 750 units, then individual A and individual C will be considered non-associated on this date.

In addition, because Association Software employs crisp logic to differentiate associated from non-associated pairs of individuals, any pair of individuals found within a distance of 501 units from each other (in this example) would be considered non-associated while individuals found within a distance of 499 units from one another would be considered associated. This potential bias must be understood by the users of this software. We encourage the use of various thresholds and numerous iterations of this procedure before a decision is made regarding the independence of animal locations for your project. We also encourage the use of a spatial threshold that is 'realistic' for your study species and compatible with the methods you have used to record your location data.