• Circadian rhythm: pattern of behavioral activity aligned with 24 hour cycle (AKA biological clock); daily cycle of rest and activity
    • Can persist without external cues but cues can help → light can maintain synchronization
      • Biological rhythms can be linked to light/dark and lunar cycles
  1. Day/Night Rhythms found in all animals in response to predator habits or environment
  • Diurnal animals are active during day and sleep at night
    • Communicate mostly with auditory and visual signals
  • Nocturnal animals are active at night and rest during day
    • Communicate mostly with auditory and olfactory signals

Changes to Behavioral Rhythms in Response to Season Changes

  • Causes for changes in behavioral rhythms → seasonal changes → changes in weather, length of day, availability of food
    • So animals adjust behavior to maximize fitness and take advantage of benefits
  1. Hibernation: extended period of sleep to avoid hostile environment during winter
  • Hibernating reduces energy & metabolic maintenance by lowering body temperature and using fat as energy
  1. Estivation: dormancy during summer
  • Protect from drying out by burrowing or climbing in plants
  1. Courtship and mating: often during spring with warmer weather and more food → provide energy and nourishment
  2. Migration