Woodpeckers

Photo by Stan Tekiela

by Stan Tekiela
© NatureSmart

April 18, 2022

Once again, I found myself sitting outside in my small photo blind trying to capture a handful of images of birds in a winter/snowy setting. The temperatures where a balmy minus 5 below zero and I was starting to feel the cold penetrate my many layers of clothing.

I was fortunate enough to have a few distinct species of woodpecker come to my feeding station and I was hoping to capture a couple images of these birds. But of course, my mind started to wonder, and I started to think about all the unique and interesting adaptations and behaviors of woodpeckers.

 Let’s start with one of a woodpeckers more unique behaviors. You might not give this much thought but the way that woodpeckers land on a tree is unusual. When a woodpecker lands it is on a vertical surface, like the trunk of the tree. All other birds land on horizontal surface, such as a branch with the aid of gravity. Woodpeckers land on the vertical surface of the tree by clinging to the tree as if gravity doesn’t exist. They can do this because they have specialized feet. Their toes are different from most other birds. They have two toes pointing forward and two toes pointing backwards. Other birds have three toes forward and only one backwards. The second toe pointing backwards gives the woodpeckers a greater ability to cling to the side of trees, defying gravity.

Woodpeckers have extremely stiff tail feathers. The tail plays a crucial role in clinging to the side of a tree. The feet are only two legs of the tripod that the woodpecker needs to cling to a vertical surface. The tail is the third leg and is absolutely essential. They push so hard on the tail that the feathers often bend under the pressure.  

The fact that woodpeckers excavate holes in trees is totally amazing. What is even more amazing is that they excavate these cavities with their face. Seriously, they use their beak, which would be comparable to our teeth, to chisel holes in trees. If you don’t think this is amazing, I challenge you to pick up a piece of firewood and excavate a hole in it with any part of your own body.

Sure, excavating holes in trees is amazing but taking it one step further, they do this without suffering any brain injury (concussion). Studies shows that on average a woodpecker pecks or drums on the hard surface of a tree about 12,000 strikes per day. That’s a lot of impacts for the brain to endure every day. So how do they accomplish this without damaging their brain? As are most things in nature, it’s a combination of factors.

First, the brain of the woodpecker has a smooth surface which allows for more contact with the inside of the skull. This might seem counter intuitive but having a brain that sloshes around the skull isn’t good for high impacts. Woodpeckers have extraordinarily little space between the skull and brain, called the subdural space, and therefore don’t have much cerebrospinal fluid, unlike our own skull and brain. Again, this helps to stabilize the brain within the skull.

The bill of the bird is located in a position that allows the maximum force from the impact to be concentrated just below the brain. Woodpeckers also have tongues so long that the tongue leaves the mouth of the bird and wraps around the outside of the skull helping to also cushion the brain.

The size of a woodpecker’s brain is relatively small, and therefore doesn’t have a lot of mass. Since the brain is lightweight, it doesn’t build up enough force to cause damage to the brain upon impact. Woodpeckers also have a small cushion-like material between the bill and skull which helps to absorb each impact. All these things add up to a woodpecker who doesn’t get a concussion when it bangs its face against a tree.

This is just the beginning of how different woodpeckers are from other birds. Any, this is why I find myself sitting in sub zero temperatures just to capture a few images of the amazing woodpeckers. Until next time…

Stan Tekiela is an author/naturalist and wildlife photographer who travels the U.S. to study and capture images and video of wildlife. He can be followed on Instagram.com, facebook.com, and twitter.com. He can be contacted via his web page at www.naturesmart.com.