Predators prey and physics the distinction between v
Predators, prey, and physics: the distinction between v and a can be a life or death matter…. http: //www. flickr. com/photos/stignygaard/2485557955/ © J. A. Bolker and D. C. Meredith, UNH, 2009 1
v (m/s) gazelle 20 lion 10 4 8 12 16 t(s) data from films Data from Elliott, P. , Cowan, I. M. , and Holling, C. S. 1977. Prey capture by the African lion. Canadian Journal of Zoology 55(11): 1811 -1828. © J. A. Bolker and D. C. Meredith, 2 UNH, 2009
What can we infer from the plot? A. The lion should chase the gazelle as long as possible to maximize the chance of catching it. B. The lion should chase the gazelle until the gazelle reaches its maximum velocity. C. The lion should give up the chase if it hasn’t caught the gazelle within 4 seconds. D. The gazelle doesn’t have to worry about lions, because it can run about twice as fast. E. The gazelle travels farther than the lion does in the first two seconds of v (m/s) the chase. gazelle 20 lion 10 © J. A. Bolker and D. C. Meredith, UNH, 2009 4 8 12 16 3 t(s)
Insert graphic from primary or other source, with appropriate copyright permission initial accel. lion gazelle 9. 5 m/s 2 4. 5 m/s 2 top speed 14 m/s 27 m/s (estimated) Data from Elliott, P. , Cowan, I. M. , and Holling, C. S. 1977. Prey capture by the African lion. Canadian Journal of Zoology 55(11): 1811 -1828. © J. A. Bolker and D. C. Meredith, UNH, 2009 4
“The ability of a predator to catch prey may depend more on its acceleration than on its maximum speed. Indeed, a predator with superior acceleration may be able to catch prey even if its top speed is lower than that of the prey. ” -- R. M. Alexander, Principles of Animal Locomotion (Princeton University Press, 2003) © J. A. Bolker and D. C. Meredith, UNH, 2009 5
Dinosaurs, too? http: //www. flickr. com/photos/46183897@N 00/2705371948/ © J. A. Bolker and D. C. Meredith, UNH, 2009 6
Glen Rose trackway Texas/AMNH Insert graphic from primary or other source, with appropriate copyright permission • Ongoing debate among paleontologists • May record pred/prey interaction • Stride-matching similar to behavior of extant predators • Physics as window on past biology © J. A. Bolker and D. C. Meredith, UNH, 2009 7
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