NEW SCIENTIST: why do birds never fall off their perches when sleeping?
- "Birds have a nifty tendon arrangement in their legs. The flexor tendon from the muscle in the thigh reaches down over the knee, continues down the leg, round the ankle and then under the toes. This arrangement means that the birds body weight cause the bird to bend its knee and pill the tendon tight, so closing the claws. Apparently this mechanism is so effective that dead birds have been found grasping their perches long after they have died."