Sources:PowerPoint, Web, text (134-144, 367-372)

1. Endure, Evade, Expire

2. Outline for Enduring

• Temperature Stress
  • Reduce Heat Input: spines for insulation
  • Dissipate Heat: long extremities
  • Tolerate Hyperthermia: C4 Photosynthesis
• Water Stress
  • Water Conservation
    • Decrease Cutaneous Water Loss: use waxes in outer covering.
    • Decrease Excretory Water Loss: produce uric acid
    • Decrease Respiratory Water Loss: drought deciduous
  • Tolerate Dehydration: A saguaro can tolerate an 80% reduction in water from the body.

3. Water Storage: succulence, fat storage
Spatial: migration, microclimate selection
Temporal: nocturnal, torpor

4. Uric acid uses 10X less water, but costs additional energy. Birds, snakes, lizards, some insects do this.