Big-horn sheep versus vehicle
Jearl Walker www.flyingcircusofphysics.com
April 2016 In this short video we see two big-horn sheep running head-long into each other, a pre-mating procedure. When a vehicle gets in the way, guess what happens.
Head-banging sheep are usually protected by several features. (1) Their horns bend so as to prolong the duration of the collision and thereby reduce the force in the collision. (2) The skull bones (cranial bones) also shift or rotate about their junctions (sutures) in a spring-like or hinge manner in order to cushion the blow to the head. (3) Much of the energy of a collision ends up in the strong neck muscles of the animals or in the sinuses. Although the collisions look terribly violent, the muscles and horns of the animals have evolved to the point where breaking a horn or hurting the brain is unlikely.
https://www.youtube.com/watch?v=6jgjk3DsN7c&ebc=ANyPxKocbzrDjhtNC7UoOMMdB5teO2bD5pbVSUTzDa8Y4BnO2uM3YsvmUrfQ6udCjfu2fjyhbIuMXVYOc-KWjwD6u8wc7Nnw1w big horn sheep hitting motorbike
https://www.youtube.com/watch?v=X2g6a1jIweI&ebc=ANyPxKocbzrDjhtNC7UoOMMdB5teO2bD5pbVSUTzDa8Y4BnO2uM3YsvmUrfQ6udCjfu2fjyhbIuMXVYOc-KWjwD6u8wc7Nnw1w Bam Bam
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Journal reference style: author, title, journal, volume, pages (date)
· Kitchener, A., “The effect of behaviour and body weight on the mechanical design of horns,” Journal of Zoology, London (A), 205, 191-203 (1985)
· Kitchener, A., “An analysis of the forces of fighting of the blackbuck (Antilope cervicapra) and the bighorn sheep (Ovis Canadensis) and the mechanical design of the horns of bovids,” Journal of Zoology, London, 214, 1-20 (1988)
· Jaslow, C. R., and A. A. Biewener, “Strain patterns in the horncores, cranial bones and sutures of goats (Capra hircus) during impact loading,” Journal of Zoology, London, 235, 193-210 (1995)
· Lundrigan, B., “Morphology of horns and fighting behavior in the family Bovidae,” Journal of Mammalogy, 77, No. 2, 462-475 (1996)
··· Courtney, M., and A. Courtney, “Sheep collisions: the good, the bad, and the TBI,” (24 Nov 2007) available at http://arxiv.org/abs/0711.3804.This online posting is largely a criticism of an example I wrote in my textbook. The authors have some interesting points but appear to be unaware of the research papers and measurements that had already been published in reviewed journals. My example was based on those papers.
··· Farke, A. A., “Frontal sinuses and head-butting in goats: a finite element analysis,” Journal of Experimental Biology, 211, 3085-3094 (2008)