Woodpeckers get their name from their unique feeding methods- pecking wood. They can hammer into the bark with 1,000 g of force (1,000 times the force of gravity) at around 20 pecks per second. Comparing to humans, a blow of 100 g would ultimately result in brain damage, or even death. How does a bird manage to live its life taking multiple blows to the head? Well, keep scrolling, and we will both find out together (Birdwatching, 2017).
Adult male beginning to make an impact on this tree. I wonder if he’ll need an aspirin.
Physical Adaptations
skull
The skull of the Pileated Woodpecker is remarkable in its ability to absorb shock.
The lower mandible (beak) is curved upwards, creating a perfectly straight chisel in which to pierce the wood. Spongy plates within the skull help to absorb impact much like the foam we see in our bicycle helmets.The lower mandible is slightly longer, and is believed to direct the stress of the impact.
brain and muscles
The brain is the main area of concern here, and has been highly adapted to absorb as much shock as possible. The skull is highly muscularized, which reduces space between the skull and the brain and removes any unnecessary movement. Woodpeckers have smaller brains (compared to birds of the same size) in order to increase surface area and spread shock (Bird, 1999).
I think I’ve offended him. Dont worry little buddy, in your case a small brain with a thick skull is an incredible advantage!
the hyoid bone
A remarkable adaptation made by woodpeckers, including Pileated, is the formation of the hyoid bone within the skull. This bone wraps around the base of the skull, alongside the tongue, acting much like a seatbelt in its ability to support the skull. Below is the figures from a study conducted by Wang et al. 2011 which measured the distribution of force during a single “peck”.
A time lapse of the distribution of stress throughout the skull. As you can see, most of the stress is directed towards the lower mandible (red).
The same time lapse as shown above, however now just focussed on the hyoid bone. That same stress is still directed to the lower mandible, with the hyoid taking most of the impact and evenly distributing it throughout in the final stage (bottom right).
The eye
An extra, nylon-strength eyelid also aids in reducing injury by acting like a seatbelt for the eye. Without the eyelid there to stop it, the brute force applied to the eye would mean detachment of the retina or the eye popping right out of the socket! (Live Science, 2010)
Pileated Woodpecker skull and its adaptations to prevent brain damage. Note the small brain, Hyoid complex, strong neck, and membrane over the eye.
Other cool adaptations:
Here are some other ways woodpeckers can reduce injury during repeated impact:
- reduce rotational force- a straight peck is a safe peck! (live science)
- strong neck muscle which contracts a millisecond before impact
- lower amounts of cerebral spinal fluid which reduces neurotransmitters- a good way to reduce pain is to not even feel it at all
- an especially long rear toe (hallux), legs that are directed outwards, extra vertebrae, and an extra stiff tail all provide extra support against the sides of trees.
(Bird, 1999)
Why is this important
Most of the time, an animal tries to avoid taking multiple blows to the head. Humans on the other hand, live their lives running into things as well as each other. In the United States alone, there are over 3.8 million concussions annually. This can cause quite a concern as permanent brain damage can occur, especially in young athletes (Sharecare, 2017).
This is probably going to hurt for everyone involved.
I think we can all use our imaginations as to what happens next.
So what do Woodpeckers have to do with this? Well, thanks to some brilliant minds and a little dash of science, there have been many advances as to how we can use woodpecker anatomy to our advantage. A specialized helmet made from cardboard was modelled after a woodpecker’s spongy skull. Another fascinating invention is of a unique sports collar which utilizes a woodpecker’s supportive neck muscles. I guess there is hope for the human race after all!
Click the links above to check out the incredible advances made to reduce the frequency in sport-related concussions!
Yay!! You made it to the bottom! If you’re joining us from my previous post, and are still wondering why the Pileated Woodpecker sounds so familiar, it’s our good friend Woody Woodpecker of course! The character’s distinctive red crest and adorable giggle were inspired by the Pileated woodpecker!
References
2017. Birdwatching Daily: Why Woodpeckers can hammer without getting headaches. Madavor Media. Retrieved from https://www.birdwatchingdaily.com/blog/2013/12/10/woodpeckers-hammer-without-headaches/
2017. Sharecare: How common are concussions. Sharecare inc. Retrieved from: https://www.sharecare.com/health/head-injury/how-common-are-concussions
Wang L, Cheung JT-M, Pu F, Li D, Zhang M, Fan Y (2011). Why Do Woodpeckers Resist Head Impact Injury: A Biomechanical Investigation. PLOS ONE 6(10). doi: https://doi.org/10.1371/journal.pone.0026490
2010. Live Science: Why dont woodpeckers get headaches? TechMediaNetworks, Inc. Retrieved from: https://www.livescience.com/32709-why-dont-woodpeckers-get-headaches.html
Bird, D. (1999). Knocking on wood: Why woodpeckers don’t get splitting headaches. The Gazette Retrieved from http://ezproxy.viu.ca/login?url=https://search.proquest.com/docview/433545212?accountid=12246
Very cool! While watching the videos in your first blog post, I was thinking to myself “how do these birds avoid getting massive headaches?”!! I really enjoyed the commentary you included for your photos and videos and how you linked everything together, well done! Do you know if all species of woodpeckers have the same level of these adaptations? I’m curious if a woodpecker with a smaller and shorter bill such as the Downy Woodpecker would be as susceptible to brain damage or injury due to pecking compared to the Pileated Woodpecker!
Hi Chanelle, thank you so much, I’m glad you enjoyed the post. To answer your question all woodpeckers, including the downy, use the same adaptations to avoid brain damage. The downy is just much more “compact” than the pileated.
Awesome! It’s always amazing to me how far away you can hear them pecking tree trunks.
Do they have any adaptations for shock absorption within their ears? I always see them listening for things under the bark between pecking and the ear is such a sensitive system – they have must account for that somehow.
Very interesting post and funny too. I grew up watching Woody Woodpecker (Woody le pic, as translated in French). Like Braden, I’ve always wondered how they select which dead tree to hammer and how they target where to drill. Presumably there are external signs like bits of sawdust from carpenter ants, but they seem pretty efficient at narrowing down where to focus drilling. Did you come across the cues they use?
Hi Eric (and Braden) as for your question, I couldn’t find any solid answer to how they obtain their insect food (as in there is little on the behaviour of actually obtaining the food itself, rather the research is more focussed on WHAT they are eating rather than HOW they find it). However many people (on blogs, and enthusiast websites) are saying the birds can hear the ants underneath the bark, while one bird enthusiast suggests that they can tell where the insects are based on how “echo-y” the bark sounds upon drumming, I found this one quite creative . Through the lack of actual research on the second hypothesis, and the fact that drumming is primarily a display behaviour, I’m leaning towards the auditory approach!
As for how their ears stay intact, the skull consists of so much tightly packed, spongy tissue that the inner ear avoids any extra damage (think of the entire brain/sensory system as someone riding on a rollercoaster, with all of those extra restraints to prevent it from rocking around the seat) . Another adaptation is how the force is directed to the hyoid complex and down towards the lower portions of the beak and skull. The key here is to remove as much extra movement, and direct as much force away from critical areas as possible!
Ps- My apologies Braden on my lack of a response, I had full intentions of replying. The notification came through however, the mental reminder to reply hadn’t quite stuck. Sorry again! Hope this answers your question 🙂