1. How does an animal organize its priorities?
5/13/08

2. 5/21/08: Organization of Behavior
Lecture objectives:
Develop a proximate understanding for why animals don’t exhibit several behaviors simultaneously
Understand how behavioral schedules are regulated and how they allow animals to meet the demands of a changing environment
Recognize the role that hormones play in eliciting behavioral change

3. Short-term scale: Neural command centers are responsible for activating a particular response
Center is activated through animal’s - Inhibition: active center can suppress or inhibit other centers - These inhibitory relationships may change
b, a, c, d
a, c, d, b a b c d

4. Example: praying mantis nervous system
Sex is a “no-brainer” for a male praying mantis

5. Migration, breeding, hibernation
Animals need to modulate behavior to meet the demands of environmental cycles
Daily light/dark cycle
Lunar cycle
Annual cycles: temperature/food supply
active/asleep
forage/don’t forage
Migration, breeding, hibernation
How do animals do this?

6. Do animals track their environment or have an internal clock?

7. Humans have a circadian rhythm

8. Circadian rhythms likely serve an adaptive function
Environment-independent component:
Environment-dependent component:

9. Proximate basis of circadian clock
Location:
Rhythmic changes in gene activity:

10. Other behavioral schedules
Circannual
Lunar, and food-dependent

11. Hormones play an important role in the organization of behavior
Changes in environment
Detection by neural centers
Translated into hormones
Physiological and behavioral changes; i.e. control of reproductive behavior

12. Hormones and how they work

13. Effects of hormones can be organizational or activational
Hormone action during early development
Effects are often
Activational
Hormone action on tissues
Effects are often
Female egg
Concentration of JH
Light feeding
Heavy feeding + royal jelly
nurse
forager

14. Organizational or activational?
Example: Hormones mediate the effects of mating on the behavioral priorities in male Japanese quail
Organizational or activational?
Time at window
Before mating
After mating
+ T
+ T + A.I.

15. Example: Photoperiod alters effects of estrogen (via T) on male beach mouse aggressiveness

16. The precise role of hormones varies across species