Tarsus

The bird’s lower leg segment between the ankle joint and toes. It is formed mainly by fused bones and is commonly covered with scales.

Bird leg: The hind limb of a bird, extending from the hip to the toes. The tarsus is one segment of this larger limb.
Intertarsal joint: A joint within the ankle region of a bird’s leg. Its motion helps define the tarsus’s articulation with the lower leg.
Avian osteology: The study of the bones of birds. The tarsus is a prominent region in bird skeletal anatomy.
Tarsus (anatomy): The cluster of small bones in the human ankle, including the talus and calcaneus. In humans, tarsus names ankle bones rather than the bird’s lower-leg segment.
Bird ankle: The joint between a bird’s lower leg and tarsus. This joint marks the tarsus’s upper boundary.
Extensor tendon: A tendon that transmits muscle force to extend a joint. Extensor tendons cross the tarsus to straighten the toes.
Bird banding: A research and conservation method that marks birds with individually numbered bands. Banders measure the tarsus as a standard indicator of bird size.
Tibia: The larger lower-leg bone in tetrapods, extending from the knee toward the ankle. The tibia lies above the bird tarsus and is a distinct leg segment.
Metatarsus: The part of a limb between the ankle and toes in tetrapods. The bird tarsus takes its name from this corresponding limb region.
Flexor tendon: A tendon that transmits muscle force to bend a joint. Flexor tendons pass along the tarsus to curl the toes.

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SecretarybirdRelated: The secretarybird’s long, bare tarsi are central to its tall, long-legged appearance.