To test these ideas, Anderson and his team observed a captive flock at the Philadelphia Zoo.
Thermoregulation was offered as a reason for the flamingos' unusual posture because it was known that legs and feet were a significant source of heat loss in birds, and keeping one leg up close to the body would conserve heat.
The rationale behind the muscle fatigue theory: Standing on one leg would prevent both leg muscles from stiffening and tiring out, so that if a predator came along, the flamingo would be able to get moving faster.
