1. Sign Stimuli
1. European robin

2. 2. Herring Gull
-chick pecks at parent’s beak to obtain regurgitated
food
Cues??

3. Two major cues are involved:
1. Yellow bill

4. Two major cues are involved:
1. Yellow bill 2. Red spot on the mandible

5. Male Stickleback (Gasterosteus)
Red Belly
Red Belly +
Head Down
Posture

7. Innate Releasing Mechanisms
SIGN
STIMULUS
receptor
CNS
IRM
Match
Motor pattern
Generated
Motor output
No match
No motor pattern
generated

8. Fixed Action Pattern (FAP)
Egg Rolling in a Greylag Goose

9. A series of FAP’s can be put into a sequence
Female
Male
1. Appears -heads up display
2. Zig-zag swim
3. Swims head up
to male
4. Swim to nest
5. follows
6. Show nest
7. Enters nest
8. Tremble thrust
9. spawn

10. Should look like:
In reality: 1 2 3 4 5 6 7 8 9

11. More Fixed Action Patterns

12. Modal Action Patterns

13. SUPERNORMAL STIMULI

14. SUPERNORMAL STIMULI
Oystercatcher

15. Lorenz’s Hydraulic Model

16. Vacuum activity Time Court rolled up towel Court live female
Court female model
Court corner
of cage

17. Displacement activity