Search
Close this search box.

Word of the Week: The Zygodactyl Feet of Birds

Like what you see? Share this post

Welcome to Word of the Week!  In this blog, we will be teaching you a fundamental part of the bird, which is its feet! The term we want you to take a closer look at is, Zygodactyl! Stay tuned for a new word each Friday to amp up your nature vocabulary!

What Does Zygodactyl Mean? 

Zygodactyl [ zahy-guh-DAK-til] (adjective): describing birds having the toes of each foot arranged in pairs, with two toes in front and two behind.

The Legs and Feet of Birds 

The feet and legs of birds come in a variety of different shapes and sizes. This is because they need to accommodate the different functions of various species of birds. 

Because of the way the bird is structured, many functions that the forelimbs (where the wings are located) would perform are done by the beak and hindlimbs. Though the hindlimbs are used to help birds accelerate to flight, they also have many other duties. 

First, is using their legs for locomotion such as walking, running, swimming, or climbing. They also use these limbs for perching or clinging. To help them hunt, look or even carry food birds will use their back legs. When scratching the ground to look for food some such as wild turkeys will use one leg, while others such as sparrows will use both legs.

Another function of the hindlimbs is for reproduction-related tasks. Birds that lack a brood pouch will use their feet to help incubate their eggs.

The hindlimbs of birds have been used to help preen and clean by using a special claw. Some species of birds will even use it to clean their heads.   

The Toe Arrangements

Most birds are classified as animals that will walk on their toes. Just the function of the hindlimbs of birds has many functions to them, there are also many different arrangements of the toes of birds. There are five main typical arrangements of toes in birds that are the following:  

  1. Anisodactyl: three toes in the front and one in the back. This arrangement is seen in almost all songbirds and some perching birds.
  2. Heterodactyl: two toes in the front and two in the back. The inner front toe of these birds is reversed. This arrangement is only seen in trogons.
  3. Syndactyly: three toes in the front and one in the back. The inner and middle toes are joined together. You will find this arrangement in kingfishers and hornbills.
  4. Pamprodactyl: two toes in the front and two outer parts of its body. These two outer toes can move freely forward and backward. This is seen in mousebirds and some swifts. Some swifts will move all four of their two forward and use them as hooks to hang.
  5. Finally, we have zygodactyl. This unique foot formation, which can look like an X or a K, allows birds to grip things more efficiently.

 

Zygodactyl
Image credit: Pexels

The Claws

Regardless of the different toe arrangements, all birds have claws at the end of their toes. These claws are typically curved, and their size will depend on the size of the bird. Typically, the bigger the bird the bigger the claw will be. However, in large dwelling birds like the ratites, the claws will become straight. 

Some species such as nightjars, or herons, will have comb-like serrations on the claw that is in the middle of the toe. This can aid in scratch preening.  

Species That Have Zygodactyl

In woodpeckers, their zygodactyl feet give them the ability to easily climb and grasp onto vertical tree trunks or other structures.

In birds like parrots, zygodactyl feet can provide an amazing amount of dexterity especially for handling food or moving from branch to branch.

In some birds of prey, specifically ospreys and owls, their zygodactyl feet give them the ability to grasp squirmy prey with incredible strength. In fact, unlike most other zygodactyl birds, owls and ospreys can pivot one of their back toes forward if they need it. This means that at times, their feet might look anisodactyl (tree toes pointing forward and one pointing backward) like those of most perching birds.

Just like people need their feet to stand up and move around, so do birds! Though their feet and legs may have some more functions, the basics remain the same. Keep an eye out for birds with zygodactyl feet on your next visits to High Park!

At High Park Nature Centre, one of our goals has always been to continue the education of people when it comes to nature and the environment around them. When encourage you, to check out the programs we offer, have a look at our book club or keep a close eye on our blog! If you want to get involved come volunteer with us!  

BONUS TIP: In winter, if you’re looking at bird tracks in the snow and notice prints that are shaped like a “K” or and “X” you’ll know that it’s a bird’s zygodactyl feet. This unique foot shape can really help you narrow down the possibilities of who made those tracks!

Tags: