Fig. 1. (A) Infrared thermogram of a golden-mantled ground squirrel. (B) Actual image of a squirrel (not taken simultaneously with A) to demonstrate the angle of the body (but not the head) at which the thermogram was taken. The squirrel was usually facing the camera and, hence, the head and front legs were clearly visible, with the cooler flank region dominating the rear part of the image.