View of Mt' Whitney

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View of Mt. Whitney
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Population distribution, size

• Review of distribution types
• Population density and body size
• Seven forms of rarity

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Global distribution types

• Cosmopolitan (worldwide, wherever habitat is
  suitable
• E.g., cattails, fruitflies
• Endemic (restricted to one area)
• E.g., giant sequoia, Palos Verdes blue
• Disjunct (widely separated)
• E.g., creosote bush, maples

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Creosote bush regular distribution
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Examples of random distribution most
weeds Example of regular distribution creosote
bush Heliconid butterflies Examples of clumped
distribution flocking birds, schooling fish
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Heliconid butterfly
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Or, Why Big Fierce Animals are Rare
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• Seven forms of rarity
• Range size large or small
• Habitat tolerance wide or narrow
• Local population size large or small
• Each population has 2 possible variants of these
  3 factors. If it has one or more of the
  underlined variants, the species tends toward
  rarity.

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How to estimate population size (N)

• Mark a subset of individuals (M)
• Release M
• Recapture another subset after a delay (n)
• Count marked individuals (m) in subset n
• Compare ratios M/N m/n
• N M(n/m)
• Problems with this method?

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How do you mark a tree frog?
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Australian gecko
Speaking of amphibian toes . . .