Lecture 13

Question 1

What is behavior?

Answer 1

• a response to a stimulus mediated by the nervous system

Question 2

What is stimulus?

Answer 2

senses

• external (ex. sight, touch, smell, sound, etc.)
• internal (ex. feeling hunger, fatigue, fear, pain, etc.)

Question 3

What is the response to stimulus?

Answer 3

• the action of muscles or glands
• fixed (innate) or plastic (changeable)

ex. stimulus is sight: presence of a potential mate. Response is male display behaviour (during breeding season)

Question 4

What is behavioural ecology?

Answer 4

• the study of behaviour in animals has historically been part of psychology
• behaviour and evolution
• integrates information from genetics, ecology, and other studies to understand the origins of behaviours and how they affect evolutionary fitness

Question 5

What are the 2 explanations (hypotheses) for probable causes of behaviours?

Answer 5

1. Proximate (mechanistic) visible causes : HOW?
2. Ultimate causes: WHY? (underlying reasons)

Question 6

What is the proximate explanation?

Answer 6

• HOW?
• mechanistic explanation
• how is this behaviour triggered?
• how does this behavior happen?

Question 7

What are 2 visual cues?

Answer 7

1. alignment
2. cohesion

Question 8

How do starlings flock & fly together? explain using the visual cues

Answer 8

1. alignment - steer towards average heading of neighbours (same direction as others)
2. cohesion - move towards average position of neighbours, and avoid overcrowding

Question 9

What is the ultimate explanation?

Answer 9

• WHY
• evolutionary explanations are often needed to explain why a certain behavior exists

Question 10

Why do starlings flock?

Answer 10

• flocks may be more efficient at feeding (finding food sources)
• avoiding predators: more eyes to spot predators; an individual in a flock has a bettwe theoretical chance of surviving to breeding age than a solitary individual (increase fitness)

Question 11

explain why male Australian redback spiders commit suicide by females using proximate and ultimate explanation

Answer 11

proximate cause: male presents his body to jaws of female after mating

ultimate cause: higher fitness achieved for male by prolonged mating (2x) and then feeding the female after sperm transfer completed!

Question 12

explain innate behavior

Answer 12

• occurs completely the first time it is performed, no learning required
• strong GENETIC component

Question 13

explain learned behavior

Answer 13

• develops and changes in response to environmental stimuli
• strong EXPERIENTIAL and ENVIRONMENTAL componenet

Question 14

REVIEW - describing innate behaviours is tricky and controversial

Answer 14

• some psychology researchers describe an “innate fear” of snakes, spiders, bees, in humans. Wild monkeys all exhibit alarm at seeing a snake

BUT

• human babies and captive-raised monkeys who have never seen a snake are not automatically alarmed. What appears to be an innate adaptation for survival, may actually be a learned behavior

Question 15

What are FAPs?

Answer 15

Fixed Action Patterns
- triggered by a specific stimulus

• always occurs in the same form
• cannot be changed once started
• largely innate (“hard-wired”

Question 16

Who studied fixed action patters in male sticklebacks in the 1930s?

Answer 16

Niko Tinbergen

Question 17

explain this observation using proximate and ultimate explanation: breeding male sticklebacks respond aggressively to other male sticklebacks, and red in belly of models

Answer 17

Proximate explanation
- the aggressive response is triggered by the sight of the red belly (fish image without red is ignored)

Ultimate explanation (evolutionary)
- males who respond aggressively to other males are better able to defend their territory from other males. This increases their access to females, allows them to fertilize more eggs, and thus maximizes their reproductive fitness

Question 18

What is imprinting?

Answer 18

• innate behaviour that is time-limited
• some species have this behaviour after birth that bonds parents and offspring (birds especially). If parents are missing in critical period, other species or even moving objects may become bonded… (genes + environment both important)

Question 19

behavioural ecologists often study behaviours associated with what lines of questioning?

Answer 19

• obtaining food (optimal foraging behaviour); involves cost-benefit analyses
• oriented movement and navigation
• communication and cooperation (learning)
• mate choice and sexual behaviour (sexual selection)

Question 20

What are some examples of social & experiential learning and tool use?

Answer 20

• chimpanzee using a “hammer” to crack open betel nuts
• young chimpanzees learning to crack hard nuts with hammerstones

Question 21

What is a foraging behaviour?

Answer 21

• obtaining food

Question 22

explain the white pelican group feedings

Answer 22

1. group drives fish into shallow water near shore (COOPERATION EXAMPLE)
2. group feeding on trapped fish
3. individual success!

ex. pack-hunting of large animals by African wild dogs provides more food per dog than individual hunting of smaller animals

Question 23

explain the foraging alleles in Drosophila melanogaster (two behaviours, proximate cause, ultimate cause)

Answer 23

• fruit-fly larvae exhibit one of two behaviours during feeding
  
  • “ROVERS” move after feeding in a particular location
  • “SITTERS” stay in one location to feed
• Proximate cause : experiments show that this feeding behaviour depends on alleles of the foraging (for) gene
• rovers and sitters tend to behave differently when they are foraging because they have different alleles of the ‘for’ gene
• Ultimate cause: the rover allele is dominant and favoured at high population density while the sitter allele reaches high frequency in low-density populations, and these behaviours also continue in adult flies
• offspring of rovers tend to be rovers, and offspring of sitters tend to be sitters
  
  • rover alleles are favoured when population density is high (find new food sources when crowded)

Question 24

review well!
Do gerbils “weigh” the costs and benefits of foraging?

Answer 24

Hypothesis : Gerbils reconcile the risk of predation and the benefits of extra food availability

Null Hypothesis: Foraging activity is independent of predation and food availability

Experimental Setup:
1. start with 34 gerbils in each 1-hectare desert subplot in the Negev Desert of Israel

2. use the density of gerbil tracks in sampling stations as an index of foraging activity in control versus treatment subplots where:
   Treatment 1 - No owl flyovers, no extra seeds
   Treatment 2 - Owl flyovers, no extra seeds
   Treatment 3 - Owl flyovers, extra seeds of varying quantities

Prediction: a certain amount of added seeds will compensate for the decrease in foraging activity due to predation risk

Prediction of Null Hypothesis: gerbil foraging activity will be independent of the presence of owls, extra seeds, or both

Results: blah blah its a graph

Conclusion: gerbils weigh the relative risk of predation and benefits of extra seeds when they forage

Question 25

Review Digger wasps oriented movement behaviour - piloting with landmarks

Answer 25

- NIKO TINBERGEN studied NAVIGATION IN THE DIGGER WASP in the 1930s by manipulating the wasp's environment - digger wasps orient themselves spatially with reference to landmarks; if moved, wasps follow landmarks - this provided evidence of spatial learning and piloting

Question 26

review crows and jays and their good memory

Answer 26

- gray jay (Perisoreus canadensis) - Canada's National bird: found in all provinces and territories, and very friendly! - live in boreal forests, dominated by coniferous trees like pines and spruce - do not migrate, but survive cold snowy winters by cashing food among tree branches: and remembering up to 10000 locations to retrieve by piloting using landmarks!

Question 27

explain compass orientation - oriented movement behaviour

Answer 27

- many animals migrate over long distances. Some use compass orientation (movement oriented in a specific direction) to find their way - they may do this by orienting to: - Sun (& time of day) many animals and plants - North star or milky way (some dung beetles) - Earth's magnetic field (green sea turtles) - Compass orientation is an innate (genetic) navigation ability, but can be modified

Question 28

explain the migration of snow geese and other birds

Answer 28

Observation: Snow geese (and other birds) migrate north in the spring, and south in fall Proximate explanation: - the changes in temperature and day length trigger this seasonal migration - snow geese may orient themselves using the sun or Earth's magnetic field Ultimate explanation: - birds migrate north to Arctic breeding grounds in the spring where there is rich food for raising young (long days). As winter approaches, they head south to overwintering grounds to avoid cold and lack of food. (Maximize survival and reproduction) - individuals that migrated in the past had higher fitness than those who did not, establishing migration patterns

Question 29

Explain the honeybee language - communication behavior

Answer 29

- honeybees live in complex social groups - Karl von Frisch conducted studies in the 1930s & 40s that showed honeybees communicate sophisticated information through dance! - finding food is the result of learned information that depends on innate language ability - dancing female worker communicating with other workers - the ROUND dance indicates food is nearby (circle) - the WAGGLE dance indicates food is distant ( kinda figure 8). It provides information about the direction and distance of the food source - sisters observe and remember information

Question 30

Explain the honeybee waggle dance

Answer 30

- the direction of waggle run indicates direction relative to sun's position - length of waggle run indicates distance from hive

Question 31

review how bees and ants demonstrates cooperation: but

Answer 31

- "cheating" or deceitful behavior within species also happens - in bluegill sunfish, small males that look and behave like females have evolved in some populations - during spawning season, large males court a female, and the similar female-mimic male joins in and is tolerated - when the female lays eggs, the territorial male releases sperm, and so does the "sneaker" male, who then leaves - the territorial male protects the eggs until they hatch. The mimic gains fitness from eggs he fertilized without paying the cost of parental care (like cuckoos in birds) - if frequency of mimics increases, the success of "sneaking" drops...why?

Question 32

What is the evolution of behaviour by natural selection

Answer 32

- IF: for a given behaviour in a population: 1. there is heritable variation in behaviour 2. Variation in behaviour results in a fitness differential (reproductive success increased) THEN, a behaviour will evolve by natural selection NOTE: a behaviour is heritable if AT LEAST SOME of the variation is explained by variation in genes