Behavioral EcologyChapter 51 A. P. Biology Liberty Senior High School Mr. Knowles
Why study animal behavior? Understand • Human nervous system. • Child development. • Human communication. • Natural selection.
Animal Behavior • Behavior- a way an organism responds to stimuli in its environment. • Two Parts: The How?- hormone levels, nerve impulses and pathways-Proximate Causation. The Why?- adaptive value to animal’s survival or reproductive success- Ultimate Causation.
What’s the difference between stimulus and response? • Stimulus- some environmental change or factor that can be perceived by a sense. • Response- an organism’s reaction to an environmental change.
Ethology • Study of natural history of behavior. • Early ethologist, like Konrad Lorenz and Niko Tinbergen, believed behavior was based on instinct- innate. • Example: Egg Retrieval in Geese Insect--> Frog’s Tongue
Viewed Behavior in 3 Parts • Sign Stimulus- appearance of some signal. • Innate Releasing Mechanism- sensory mechanism that detects the signal. • Fixed Action Pattern- stereotyped act or behavior.
Show Me Egg Retrieval! Nature: Triumph of Life- Brain Power movie
Innate Behaviors • Determined by the genes of an organism. • Evidence: Behavioral genetics of Robert Tryon, 1940’s with rats and mazes Selected for fastest rats, after 7 generations, maze time was 1/2 the average. • Drosophila: mutant males fail to disengage females during mating. Also, courtship songs of birds are genetic.
Figure 51.8 Migration • Many features of migratory behavior in birds • Have been found to be genetically programmed
Comparative Psychologists • Behavior was due to learning. • Learning- any modification of behavior that results from experience rather than maturation. • Two Kinds: 1. Nonassociative Learning: animal forms no association between stimulus and response (habituation = no +/- reinforcement). Ex. Young birds in nest.
Learning 2. Associative Learning- behavioral alteration that involves an association between stimulus and response. The behavior is modified or conditioned (classical conditioning). Example: Young predators learning to identify acceptable prey.
Classical conditioning is a type of associative learning In which an arbitrary stimulus is associated with a reward or punishment Before stimulus Influx of alarm substances Influx of water alone Influx of pike odor Day 1 Day 3 Relative activity level Experimentalgroup Experimental group Control group Control group Figure 51.15
What human behaviors are learned? innate? Show me the video! Nova: Secrets of the Wild Child
Spatial Learning • Spatial learning is the modification of behavior • Based on experience with the spatial structure of the environment.
In a classic experiment, Niko Tinbergen Showed how digger wasps use landmarks to find the entrances to their nests EXPERIMENT A female digger wasp excavates and cares for four or five separate underground nests, flying to each nest daily with food for the single larva in the nest. To test his hypothesis that the wasp uses visual landmarks to locate the nests, Niko Tinbergen marked one nest with a ring of pinecones. RESULTS When the wasp returned, she flew to the center of the pinecone circle instead of to the nearby nest. Repeating the experiment with many wasps, Tinbergen obtained the same results. Nest No Nest Nest CONCLUSION The experiment supported the hypothesis that digger wasps use landmarks to keep track of their nests. Figure 51.14 After the mother visited the nest and flew away, Tinbergen moved the pinecones a few feet to one side of the nest.
Problem solving can be learned: -by observing the behavior of other animals. Figure 51.17
Can an animal learn anything? • Learning Preparedness- what an animal can learn is genetically determined; learning limited by instinct. Adaptive benefit. • Example: rats can associate food by smell rather than by color. pigeons associate food by color rather than sound.
(a) A male three-spined stickleback fish shows its red underside. Figure 51.3a
(b) The realistic model at the top, without a red underside, produces no aggressive response in a male three-spined stickleback fish. Theother models, with red undersides, produce strong responses. Figure 51.3b
BEHAVIOR: A male stickleback fish attacks other male sticklebacks that invade its nesting territory. PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus that releases aggression in a male stickleback. ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreasesthe chance that eggs laid in his nesting territory will be fertilized by another male. Figure 51.4
Nikolaas Tinbergen • Studied courtship behavior of the stickleback fish. • Identified a stimulus/response chain in animals. • Saw sign stimuli as social releasers.
Social Releasers • Are sign stimuli one organism provides to another to communicate: readiness to mate, location of food, potential danger • Communicate through visual, acoustic, chemical, tactile, or electrical pathways.
When a minnow or catfish is injured An alarm substance in the fish’s skin disperses in the water, inducing a fright response among fish in the area (a) Minnows are widely dispersed in an aquarium before an alarm substance is introduced. (b) Within seconds of the alarm substance being introduced, minnows aggregate near thebottom of the aquarium and reduce their movement. Figure 51.9a, b
Auditory Communication Experiments with various insects Have shown that courtship songs are under genetic control Volley period EXPERIMENT Charles Henry, Lucía Martínez, and ent Holsinger crossed males and females of Chrysoperla plorabunda and Chrysoperla johnsoni, two morphologically identical species of lacewings that sing different courtship songs. SONOGRAMSChrysoperla plorabunda parent Vibration volleys Standard repeating unit crossed with Chrysoperla johnsoni parent Volley period Standard repeating unit The researchers recorded and compared the songs of the male and female parents with those of the hybrid offspring that had been raised in isolation from other lacewings.
F1 hybrids, typical phenotype Volley period RESULTS The F1 hybrid offspring sing a song in which the length of the standard repeating unit is similar to that sung by the Chrysoperla plorabunda parent, but the volley period, that is, the interval between vibration volleys, is more similar to that of the Chrysoperla johnsoni parent. CONCLUSION Standard repeating unit The results of this experiment indicate that the songs sung by Chrysoperla plorabunda and Chrysoperla johnsoni are under genetic control.
Social Environment and Aggressive Behavior • Cross-fostering studies in California mice and white-footed mice • Have uncovered an influence of social environment on the aggressive and parental behaviors of these mice
Influence of cross-fostering on male mice Table 51.1
Desert grassland population 50 Riparian population 40 30 Time to attack (seconds) 20 10 0 Lab-raised generation 2 Lab-raised generation 1 Field Variation in Aggressive Behavior • Funnel spiders living in different habitats • Exhibit differing degrees of aggressiveness in defense and foraging behavior 60 Population Figure 51.19
Such competition may involve agonistic behavior: An often ritualized contest that determines which competitor gains access to a resource. Male competition for mates: Is a source of intrasexual selection that can reduce variation among males. Figure 51.30
A Real Life Example of Agonistic Behavior! Discovery: Anatomy of a Shark Bite video
Elephant Communication • The work of Dr. Katherine Payne • The video, 48 Hours: Something Wild, July 2001
Orientation Behaviors • Orient by tracking stimuli in environment. • Movement toward or away from stimulus- taxis. Ex. + phototaxis= insects to light. • Other movements do not involve specific orientation. Only become more active under unfavorable conditions, inactive under favorable conditions. • If activity is dependent on stimulus intensity- Kineses.
Sow bugs: Become more active in dry areas and less active in humid areas Moist site under leaf Dry open area (a) Kinesis increases the chance that a sow bug will encounter and stay in a moist environment. Figure 51.7a
Many stream fish exhibit positive rheotaxis Where they automatically swim in an upstream direction Direction of river current (b) Positive rheotaxis keeps trout facing into the current, the direction from which most food comes. Figure 51.7b
Konrad Lorenz • Studied imprinting -forming social attachments early in life. • Worked with goslings and filial imprinting. • Imprinting seen as innate.
BEHAVIOR: Young geese follow and imprint on their mother. PROXIMATE CAUSE: During an early, critical developmental stage, the young geese observe their mother moving away from them and calling. ULTIMATE CAUSE: On average, geese that follow and imprint on their mother receive more care and learn necessary skills, and thus have a greater chance of surviving than those that do not follow their mother. Figure 51.5
Conservation biologists have taken advantage of imprinting In programs to save the whooping crane from extinction Figure 51.6