Lecture 1 Flashcards
Introduction to Animal Behaviour
Innate behaviours can be modified by…
experience
e.g. parasitic wasps prefer yellow over orange, but if orange is linked to stimuli, preference can shift to orange; however, a new colour cannot be taught (not always invariant)
two types of behaviours
innate behaviours
- instinctive, minimal variation
- mistakes can be costly
- carried out regardless of an animal’s prior experiences (high genetic involvement)
learned behaviours are dependent on an animal’s prior experiences (high environmental involvement)
ethos
meaning “character” or “habit”
two types of ecological questions
- ultimate questions focus on evolutionary history and adaptive function; these are often “why” questions (e.g. “Why are most male birds more colourful than females?”)
- proximate questions focus on development and mechanisms (e.g. “What mechanisms are involved in the development of bright plumage in birds?”)
two types of non-associative learning
- habituation: behaviour is eliminated through repeated exposure to a stimulus (e.g. reduced startle responses in rats exposed to repeated loud noises)
- sensitization: behaviour is enhanced through repeated exposure to a stimulus (e.g. a child that is continuously tickled laughs harder over time)
three examples of innate behaviours
- fixed action patterns (e.g. goose egg retrieval, stickleback fish attacking things with red bellies)
- mate recognition signals (e.g. courtship displays in ducks, frog calls)
- predator avoidance behaviours (e.g. motmots avoiding attacks on coral snakes)
unconditioned vs. conditioned stimuli and responses
- unconditioned stimulus (US): a stimulus that triggers an innate response (e.g. odours)
- unconditioned response (UR): an innate response to US (e.g. salivation when smelling food)
- conditioned stimulus (CS): a new stimulus that becomes conditioned to responses over time (e.g. ringing a bell when it is time for food)
- conditioned response (CR): an innate response to CR (e.g. salivation when hearing the bell)
Niko Tinbergen
founder of experimental ethology
three types of associative learning
- imprinting: exhibited by young animals when they form attachments or develop concepts of their own identity; “parents” are necessary
- classical conditioning: innate behaviours are conditioned to be triggered by new stimuli through repeated exposure (e.g. Pavlov’s dogs)
- operant conditioning: trial-and-error learning; a behaviour is modified over time through its association with an outcome (i.e. reward or punishment)
individual-based ecology
focuses on individuals and how they interact with their environments
behavioural ecology
focuses on behaviour of animals in response to their environments
two types of learned behaviours
non-associative learning
- occurs in the absence of an outcome
- animal alters behaviour after exposure to a stimulus
- repeated exposure can eliminate or enhance behaviour
associative learning
- occurs when two events are linked (learning tied to an outcome)
two types of innate behaviours
- reflexes are automatic responses to stimuli (e.g. pulling hand away from a stove)
- instincts are behaviours that are present from birth (e.g. babies sucking a mother’s nipple)
classical conditioning and Pavlov’s dogs
- US (meat) → UR (salivation)
- CS (bell) + US (meat) → UR (salivation)
- CS (bell) → CR (salivation)
fixed action pattern in geese
- when a goose accidentally kicks an egg out of its nest, it retrieves the egg (egg retrieval is an FAP)
- this behaviour persists even if the egg is tied to a string, preventing it from being brought into the nest
- a bigger egg-shaped object elicits a stronger response (i.e. hyperstimulation)
Karl Von Frisch
studied insect behaviour (e.g. decoded bee dances), and discovered bee vision differs from humans
imprinting
- behaviour develops in response to a stimulus
- flexibility limited by a sensitive period (the time period when a young animal is most able to learn a specific behaviour)
- tracks large-scale changes in environment; variation depends on the environment
- mistakes can be very costly to fitness
Tinbergen’s four questions
- developmental (proximate description of a behaviour’s origin): How is the behaviour acquired over an individual’s lifetime?
- mechanistic (proximate description of a behaviour’s implementation): How is the behaviour caused through neural, muscular, and other processes?
- evolutionary (ultimate description of a behaviour’s origin): Where and how did the behaviour arise in the past?
- adaptive (ultimate description of a behaviour’s implementation): How does the behaviour enhance the survival and/or reproduction of individuals?
Tinbergen’s digger wasp experiment
Tinbergen put a circle of pinecones around a wasp’s burrow
- when the pine cones moved, the wasp couldn’t find the burrow; the pine cones acted as a landmark for the burrows
- when the pine cones are shaped in a triangle, and a separate circle of rocks is made, the wasp couldn’t find the burrow; the arrangment of the landmark was what mattered, not the type of landmark
Konrad Lorenz
founder of ethology, and discoverer of fixed action patterns
fixed action pattern (FAP)
- an innate motor response that is initiated by an environmental stimulus
- once initiated, behaviour goes to completion
- can be triggered under inappropriate circumstances
- similar among individuals of a species
positive vs. negative reinforcement and punishment
- positive reinforcement: behaviour is promoted by presenting a good stimulus after a certain behaviour (e.g. a dog gets a treat when sitting on command)
- positive punishment: behaviour is eliminated by presenting a bad stimulus after a certain behaviour (e.g. a cat is sprayed with water when it jumps onto the counter)
- negative reinforcement: behaviour is promoted by removing a bad stimulus after a certain behaviour (e.g. a seat belt alarm stops sounding when a person puts their seatbelt on)
- negative punishment: behaviour is eliminated by removing a good stimulus after a certain behaviour (e.g. a child getting grounded for lying)
operant conditioning
- exploratory behaviour leads to an accidental reward
- subsequent rewards reinforce behaviour
- termination of rewards leads to an extinction of behaviour
- used to train animals and children
three types of imprinting
- filial: social attachment to a parent (e.g. young geese imprint on an adult animal, following that adult around)
- habitat: attachment to a particular environment (e.g. young salmon imprint on rivers, using chemical cues to locate the same river when its time to lay eggs)
- sexual: social attachment to a sexual partner (e.g. cross-species finches are attracted to finches that look like their parents)
