Some Food Web stuff and back to energy

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Some Food Web stuff and back to energy
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Gary Polis work

• Many species in food webs (30 vs. 20 or so)
• Many connections in webs (289 vs. 30-40)
• 3) Food chains are longer than thought (7.3 links
  vs. lt3)
• 4) Omnivory rules and is not exceptional (78 vs.
  20-something)
• 5) Cycles are common e.g. cannibalism and mutual
  predation

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Food Webs are complex

• Example Parurcontonus mesaensis, a desert
  scorpion
• Many prey species, not just a few
• Cannibalism (or cycling) may be more common than
  we think

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More food web generalizations

• 6) top predators are rare, because nothing is
  really at the top
• 7) This questions the idea of a trophic level
• Cycling further complicates this idea
• If A eats B and B eats A, what trophic level is
  A? B?