*2.2. Data Collection*

All thermal images were taken using the FLIR530TM Thermal Imaging Camera. Thermal images of each of the koalas were taken every 30 min between 8:00 and 17:00 (9 h a day) over three consecutive days in May 2018 for a total of 171 images (57 images per individual). Each image taken was focused and centred to the koala to incorporate as much of the body features within the image (Figure 1). Each image was taken within 1 m distance to the koala.

**Figure 1.** Thermal images of Erica on 14 (**left**) and 16 (**right**) May 2018 at Wildlife Sydney Zoo taken using a FLIR530 Thermal Imaging Camera. Both images show a minimally obstructed view of Erica perched on a branch, with the specifically selected body features highlighted by the black circular reticles.
