Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Temporal food scarcity, for example, is likely more common on islands (especially on small ones; see Van Damme 1999; Cooper and Vitt 2002 and references therein) and might force insular lizards towards frugivory or herbivory in general.
Category: