Lecture Eight - Animal behaviour Flashcards
Define behaviour.
Nervous system’s response to a stimulus carried out by the muscular or the hormonal system that ultimately increases survival and reproductive success.
Behaviour helps an animal to:
- Obtain food.
- Find a partner for sexual reproduction.
- Maintain homeostasis.
Behaviour is the outcome of many complicated processes and is subject to natural selection.
What is ethology?
The scientific study of animal behaviour.
Nowadays very interdisciplinary and somewhat split between behavioural neuroscience, behavioural genetics and behavioural ecology.
What were Tinbergen’s four questions?
1) What stimulus elicits the behaviour, and what physiological mechanisms mediate the response?
2) How does the animal’s experience during growth and development influence the response mechanisms?
3) How does the behaviour aid survival and reproduction?
4) What is the behaviour’s evolutionary history?
Questions one and two are proximate causes (why?).
Questions three and four are ultimate causes (how?).
Explain Tinbergen’s first question - What stimulus elicits the behaviour, and what physiological mechanisms mediate the response?
Fixed action patterns - triggered by sign stimulus.
E.g.the male-male aggression in three-spined sticklebacks, which involved the sticklebacks become aggressive only at other red bellied fish-like replicase, and not aggressive towards identical stickleback without the red belly.
Kinesis - change in activity in response to stimuli (undirected).
E.g. when looking in the dark for one’s keys.
Taxisi - more or less automatic, oriented movement towards or away from a stimulus (directed).
E.g. when looking in the light for one’s keys.
Migration - regular long distance change in location. The stimulus can be e.g. change in day length.
What is a signal?
In behavioural ecology, a signal or a sign stimulus is a stimulus that causes a change in another animals behaviour.
Communication is the transmission and reception of signals between animals.
Can result in a stimulus response chain.
Explain Tinbergen’s second question - How does the animals experience during growth and development influence the response mechanisms?
Innate behaviour - is developmentally fixed and under sting genetic influence (e.g. fixed action patterns).
Learning - is the modification of behaviour based on specific experiences.
Habituation - (reduced response) is a form of learning behaviour, the diminishing of a response to a frequently repeated stimulus.
Sensitisation - (increased response) the increase in response to a repeated stimulus.
Imprinting - come to recognize (another animal, person, or thing) as a parent or other object of habitual trust.
Spatial learning - learning of ones surroundings.
Cognition - is a complex form of learning where reason, observation, memory and judgement are used to decide on a course of action.
E.g. Pavlov’s Dog experiment - classical conditioning or associative learning = a learning process that occurs when two stimuli are repeatedly paired: a response which is at first elicited by the second stimulus is eventually elicited by the first stimulus alone.
Explain Tinbergen’s third question - How does the behaviour aid survival and reproduction?
Genetic components of behaviour evolve though natural selection.
Behaviour affects fitness (e.g. by influencing foraging or mate choice).
Mating behaviour:
Seeking or attracting mates.
Choosing among potential mates.
Competing for mates.
Charles Darwin on sexual selection: “…selection which occurs within one sex as a result of competition among members of that sex, for reproduction with a member of the opposite sex.”
Females usually expend more energy in the finding of a mate, as they will have to further expend energy in the pregnancy, it is therefore in their interests to have a worthy mate.
Mechanisms for sexual selection:
Female choice of male partner = inter-sexual.
Male-male competition = intra-sexual.
Mating relationships:
Monogamy = Male + Female (biparental)
Polygamy = Polygyny (one female with many male partners) + Polyandry (one male with many female partners).
Promiscuity = Many females mate with many males.
Alturism: one organism taking care of another organism. Inclusive fitness.
r x B > C, where r = relatedness, B = benefits and C = costs.
Evolution supports altruism under certain conditions.
Explain Tinbergen’s fourth question - What is the behaviours evolutionary history?
E.g. the evolution of food preference in gated snakes and the evolution of species-specific sex pheromones in moths.
