{"id":761,"date":"2017-10-27T18:27:16","date_gmt":"2017-10-27T18:27:16","guid":{"rendered":"http:\/\/wordpress.viu.ca\/biol325\/?p=761"},"modified":"2017-11-11T18:19:58","modified_gmt":"2017-11-11T18:19:58","slug":"linebacker-vs-woodpecker-who-can-better-take-a-tackle","status":"publish","type":"post","link":"https:\/\/wordpress.viu.ca\/biol325\/2017\/10\/27\/linebacker-vs-woodpecker-who-can-better-take-a-tackle\/","title":{"rendered":"Linebacker vs Woodpecker: Who can better take a tackle?"},"content":{"rendered":"

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).<\/p>\n

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Adult male beginning to make an impact on this tree. I wonder if he’ll need an aspirin.<\/p><\/div>\n

Physical Adaptations<\/h3>\n

skull<\/h4>\n

The skull of the Pileated Woodpecker is remarkable in its ability to absorb shock.<\/p>\n

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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.<\/p>\n

brain and muscles<\/h4>\n

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 \u00a0movement.\u00a0<\/span>Woodpeckers have\u00a0smaller brains (compared to birds of the same size) in order to<\/span>\u00a0increase surface area and spread shock (Bird, 1999).<\/span><\/p>\n

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I think I’ve offended him. Dont worry little buddy, in your case a small brain with a thick skull is an incredible advantage!<\/p><\/div>\n

the hyoid bone<\/h4>\n

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\u00a0et al.\u00a0<\/em>2011<\/a> which measured the distribution of force during a single “peck”.<\/p>\n

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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).<\/p><\/div>\n

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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).<\/p><\/div>\n

The eye<\/h4>\n

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)<\/p>\n

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Pileated Woodpecker skull and its adaptations to prevent brain damage. Note the small brain, Hyoid complex, strong neck, and membrane over the eye.<\/p>\n

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Other cool adaptations:<\/h3>\n

Here are some other ways woodpeckers can reduce injury during repeated impact:<\/span><\/p>\n

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  • reduce rotational force- a straight peck is a safe peck! (live science)<\/li>\n
  • strong neck muscle which contracts a millisecond before impact<\/li>\n
  • lower amounts of cerebral spinal fluid which reduces neurotransmitters- a good way to reduce pain is to not even feel it at all<\/li>\n
  • 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.<\/li>\n<\/ul>\n

    (Bird, 1999)<\/span><\/p>\n

    Why is this important<\/h3>\n

    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<\/a> annually. This can cause quite a concern as permanent brain damage can occur, especially in young athletes\u00a0(Sharecare, 2017).<\/span><\/p>\n