Animal Behaviour

Question 1

What is Behaviour?

Answer 1

• An action carried out by muscles under control of the nervous system
  » Stimulus → sensory systems → integration (eg, in the CNS) → motor neuron outputs that constitute the behaviour
  » Discrete sensory inputs can stimulate both simple and complex behaviours

Question 2

Why is behaviour an important factor for an animals survival?

Answer 2

• Behaviour is an essential part of acquiring nutrients and finding a partner for sexual reproduction
• It can also contribute to homeostasis (eg, honeybees huddle to conserve heat)
• As behaviour is essential to survival and reproduction, it is subject to substantial natural selection over time

Question 3

How did Niko Tinbergen understand behaviour?

Answer 3

Niko Tinbergen: Understanding behaviour requires answering four questions

1. What stimulus elicits the behaviour?
2. How does the animal’s experience during growth and development influence the response?
3. Does the behaviour aid survival and reproduction?
4. What is the behaviour’s evolutionary history?

Question 4

What causes an animal to behave in a certain way?

Answer 4

• External stimulus detected by sensory system
  » Environmental cues, eg photoperiod (amount of light in a day), temperature, lunar phase
  » Signal produced by another animal (communication)

Question 5

What are fixed action patterns?

Answer 5

• Fixed action pattern = “sequence of unlearned acts directly linked to a simple stimulus” (hard wired neuronal connections)
• Once presented with a particular trigger (“sign stimulus”), instinctive response is consistent and usually carried to completion
• Eg, male stickleback fish attack anything with a red underside

Question 6

What are some Environmental cues for animal behaviour?

Answer 6

• Alternation of light/dark cycle (photoperiod) regulate daily pattern of activity (“circadian rhythms”)
• Seasons (detected for example by length of light cycle and temperature) drive migrations
• Lunar phase (influences tides) affect marine animal behaviours

Question 7

What are animal signals?

Answer 7

• Stimulus from one animal to another is called a signal

- Signals are adapted to the animals specific environment

Question 8

What are the different types of animal signals?

Answer 8

• Signals can have a variety of forms (as many as there are sensory systems!), but most common are:
  » Visual: display of a specific stimulus to another animal
  » Olfactory: release of chemical messengers
  » Auditory: production of sound to send messages (eg, singing of birds and whales, alarm calls)
  » Tactile: touch

Question 9

What determines an animals form of communication?

Answer 9

• Form of communication depends on animal’s lifestyle and environment
  » Terrestrial mammals are mostly nocturnal animals and use olfactory and auditory signals
  » Birds (and humans) are mostly diurnal animals and use visual and auditory signals

Question 10

What are two examples of behaviour for survival in animals?

Answer 10

• Fly courtship ritual is a multisensory experience!
  » Visual, chemical, tactile, and auditory
• bees do different movements to indicate to other bees where to get food

Question 11

What are pheromones?

Answer 11

• Pheromone = chemical secreted by one animal that affects behaviour of another
• Very common among insects and mammals
  » Alarm, food trail, sex
• Can have major physiological effect on receiver
  » eg, “queen substance” in bees inhibits development of ovaries in workers and attracts workers and males to queen

Question 12

What is Innate behaviour?

Answer 12

• Some behaviours are fixed in populations (eg fixed action patterns, courtship behaviour, pheromone signaling) = “innate behaviour”
  » Shown in most (all) members of a species
  » Present at birth
  » Develops independently of environmental context

Question 13

What is learned behaviour?

Answer 13

2) Experience influences behaviour
- Modification of behaviour as a result of experience
- Capacity for learning depends on organisation of the nervous system, and learning requires changes in neuronal connectivity

Question 14

What are the different types of learning behaviour?

Answer 14

• Imprinting
• Spatial learning and cognitive maps
• Associative learning
• Cognition
• Problem solving
• Social Learning

Question 15

What is Imprinting?

Answer 15

Imprinting (studied by Konrad Lorenz)
» Recognition of parent (bonding)
» Occurs only during short “sensitive period”

Question 16

What is spatial learning and cognitive maps?

Answer 16

» Memory that reflects the environment

» Eg, Nikko Tinbergen’s experiment with digger wasp

Question 17

What is Associative learning?

Answer 17

» Making associations b/w experiences
» eg, bird eats monarch butterfly (full of toxins from milkweed) → bird vomits → bird unlikely to eat that type of butterfly thereafter!

Question 18

What are two famous associative learning experiments?

Answer 18

• Pavlov’s classical conditioning
  » Ring bell just prior to feeding … after a while, dogs salivate when they hear bell
• Skinner’s operant conditioning
  » Trial and error learning, where animal associates behaviour with reward (or punishment), and then tends to repeat (or avoid) the behaviour

Question 19

What is cognition?

Answer 19

• Cognition (thinking) is the most complex form of learning, and involves awareness, reasoning, recollection and judgment
  » Many groups of animals (incl. insects) exhibit cognition (eg, bee maze experiment)

Question 20

What is problem-solving behaviour?

Answer 20

• Problem-solving behaviour is a form of cognitive activity, which is highly developed in primates, dolphins, and some birds (esp. corvids like crows and ravens)

Question 21

What is social learning?

Answer 21

» Many animals learn to solve problems by observing behaviour of other animals
» Social learning forms the roots of culture

Question 22

How does behaviour aid success?

Answer 22

3) Behaviours can directly affect survival and/or reproductive success
» Foraging behaviour
» Mating behaviour

Question 23

What balance does an animal need to find if they are foraging?

Answer 23

• Balance between:
  » Energy costs (of foraging) and benefits (of nutrition)
  » Risk (coming across predator) and reward (finding food)

Question 24

What are the three main types of mating systems?

Answer 24

» Monogamy: 1 male and 1 female pair
» Polygyny: 1 male, many females
» Polyandry: 1 female, many males

Question 25

What determines the level of parental care in different species of animals?

Answer 25

• Level of parental care ↔ mating system
  » If young offspring cannot care for itself → high level of parental care → monogamous spp.
  » If offspring can feed and take care of self right away → males can maximise reproductive success w/ multiple mates → polygynous spp.

Question 26

What determines the level of paternal care of offspring?

Answer 26

• Certainty of paternity influences mating behaviour and level of parental care
  » Low certainty with internal fertilisation, because mating and birth (egg laying) are separated over time → paternal care rare in mammals and birds
  » High certainty with external fertilisation, where egg laying and mating occur together → paternal and maternal care equally likely to occur

Question 27

What is sexual selection?

Answer 27

• Sexual selection = natural selection in which differences in reproductive success are a consequence of differences in mating success

Question 28

What do most female animals look for when choosing a mate?

Answer 28

• Mate choice by females

» Favor seemingly arbitrary traits (eg, bright coloration) correlated with health and vitality

Question 29

What happens when a male has competition for mates?

Answer 29

• Male competition for mates
  » Agonistic behaviour, often a ritualized contest
  » Various alternative strategies (game theory)

Question 30

Can some behaviours be due to evolutionary history?

Answer 30

• Current behaviour can be a result of natural selection if …
  » The behaviour can be passed on to next generation
  Current behaviour can be a result of natural selection if …
  » The behaviour can be passed on to next generation
  • Behaviours have a genetic basis (eg, fixed action patterns, courtship rituals, foraging behaviour, male mating contests etc)
  • Learned behaviours can be passed onto offspring through social learning (culture)
• AND …
  » The behaviour conveys increased survival or reproductive success

Question 31

What is Altruism?

Answer 31

• disinterested and selfless concern for the well-being of others.
• In Zoology: behaviour of an animal that benefits another at its own expense

Question 32

How do Alturistic behaviours arise through natural selection?

Answer 32

→ if the behaviour somehow increases the individual’s fitness
» Inclusive fitness
» Reciprocal altruism

Question 33

What is inclusive Fitness?

Answer 33

• Inclusive fitness = total effect an individual has of proliferating its gene by producing its own offspring and providing aid to close relatives
  » eg, squirrel alarm call, sterile honeybees and naked mole rat queen and workers
  » There is often an association between altruistic behaviour and closeness of “relatives”

Question 34

What is reciprocal altruism?

Answer 34

• “You scratch my back, I’ll scratch yours …”

- Usually limited to animals with stable social groups (primates, pack animals)

Question 35

What is unique about human behaviour?

Answer 35

• Marked capacity for learning and highly developed symbolic language → rapid acquisition of new behaviours and skills
• Some human behaviours have less clearly defined function in survival and courtship …
  » eg, the role of “play” … practice for the unexpected and unpredictable?