Figure 4. Comparison of different material types for use in the nest building test.

Test animals were supplied with a sheet of customary kitchen roll (either uncut, A, or cut to stripes, B), a paper towel (cut to stripes, C), cotton wool (D) or a nestlet (E) and the nests produced after a trial period of 24 h are shown. For the present protocol, the nestlet was selected as the most suitable material, as it produced the most discriminative results.