Robin foot print.
Robins have three toes pointed forward and one toe pointed backward (anisodactyl.) There are very few nerves and blood vessels in their feet and that allows them— and other songbirds to land on cold perches in frigid weather. When they settle down to rest, their belly feathers cover their feet to warm them. If the weather is especially cold, many will squat to cover their feet as they eat. When a robin lands on a perch, its flexor tendons tighten, causing the toes to lock around the perch. It is an involuntary reflex. The tendons stay tight until the legs straighten.When sleeping they are able to keep their grip because the flexor tendons that extend from the leg muscles down the back of the tarsus bone and attach to the toes and lock them in position. |
When the bird begins to stand up, its legs straighten, causing the tendons to relax and the toes to unlock. This releases the feet.
