I used a thermal monocular to find the eastern screech owl in the dark. The image looks brighter than the ambient light (dark) because I used a long exposure of 20s.

THERMAL MONOCULAR.

Humans are one of the easiest to pick up with a thermal monocular even if they are hiding amongst trees for cover. You can detect people from well over 100 yards away. Warm skin and clothing radiate infrared energy that thermal monoculars pick up easily. But unlike owls and other animals, we don't have much insulation to keep the heat from escaping. On cold winter days we have to bundle up to avoid heat loss. Owls on the otherhand are well insulated with feathers. Had to use a thermal monocular to spot the owl but only its face lights up red on a thermal monocular. Much of the heat loss is through the face of the owl.