Adaptations: Stressful Conditions

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Adaptations Stressful Conditions

• WFSC 422 Ethology
• Presentation 3.1

Dr. Jane M. Packard, WFSC TAMU j-packard_at_tamu.edu
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FP Folk Psychology

• Stress is bad- avoid it
• Stress is good- it motivates us
• What is bad for humans is also bad for animals
• Conditions good for humans are also good for
  other animals

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SP Scientific Perspective

• Each species is physiologically adapted to a
  tolerance range of external physical conditions
• In response to extreme conditions above or below
  that comfort zone the body responds in a manner
  that brings the organism back into the comfort
  zone
• o First- behavioral response
• o Second- acute physiological fight/flight
  response
• o Third chronic healing response
• Interactions between body systems, e.g. dry
  tolerance and heat tolerance

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Example Tolerance range of butterfly species

• X-species adapted to xerophilous conditions, e.g.
  swallowtails
• Hot and dry
• Low elevations latitudes
• Use quarries at higher latitude
• M-species mesophilous, e.g. monarch
• medium moisture
• Higher elevations latitudes
• Dispersal corridors connecting habitat fragments-
  within tolerance range

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Response on a hot windless day

• X-species- conditions gt comfort zone
• Behavior- land in shade
• Acute- fall to ground, crawl to shade
• Chronic- immobilized (death if conditions do not
  change)
• M-species- conditions in comfort zone
• Actively feed on nectar, replenish water reserves
  in body

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Adaptations to extreme conditions

• Heat- lizards rodents go underground
• Cold- iguanas bask huddle
• Dryness-fairy shrimp- protective shield
• Rains- termites big bang reproduction swamps
  predators
• Winter starvation- bilumia then anorexia in
  ground squirrels, bears

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Example Tenebrionid beetle fog drinking

• Namib Desert- little rain but night fog
• Crawls onto crest of sandune
• Faces wind lifts abdomen
• Droplets condense trickle into mouth
• Drinking increases body water 34

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CDEF Analysis- fog drinking
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SUMMARY

• FP assume stress is the same for humans and
  other species
• SP define tolerance range for each species
• stress is outside that range
• behavior, acute, chronic responses
• examples of behavioral adaptations with the
  function of reducing stress for sedentary species
  (non-migrators)

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Action Items

• Do answers for 3.1-3.2
• Search for sources
• Benes, Kepka Konvicka 2003 (Conservation
  Biology)
• Find Parmeson, C et al. 1999
• Thomas, C.D. 1995, 2000
• Warren, M.S. 1993
• Post to WebCT discussion Unit 3