Animal Behaviour –Part I SBI3UP

What is Animal Behaviour? Everything an animal does and how it does it, including: Muscle-powered activities EX.singing Non-muscular activities EX.secreting hormones Learning EX.Memory of song

What Causes Animal Behaviour? Can be explained based on : Proximate questions “how?” Ultimate questions “why”?

Ex. Each year, Emperor penguins lay 1 egg, pigeons lay 1-2 eggs, gulls lay 3 eggs, the Canada goose lays 4-6 eggs, and the American merganser lays 10-11 eggs. What determines clutch size in birds? We must distinguish between the proximate and ultimate causes…

Proximate Questions Focus on environmental stimuli that triggers a behaviour The “how” questions Ex: “How” does each individual bird have a different clutch size? Based on physiological factors that control ovulation and egg laying

Ultimate Questions Address evolutionary significance of a behaviour The “why” questions Ex: “Why” do individual birds produce different clutch sizes? Based on selective factors, and always involve evolutionary arguments about adaptations.

Proximate vs. Ultimate Factors Proximal factors that determine clutch size are affected by how an individual bird decodes its genetic info on egg laying Ultimate factors have to do with changes in this genetic program through time and the reason for the change E.g. modified by age of female, spring weather, habitat sustainability

Ethology scientific study of animal behavior Conceptual foundations established by: Niko Tinbergen (1963) Karl von Frisch Konrad Lorenz

Tinbergen suggested 4 questions that must be answered to fully understand any behavior… Causation: What is the mechanistic basis of the behaviour (ie.chemical, anatomical & physiological mechanisms)? Development: How does development of the animal from zygote  mature individual, influence the behaviour? Evolution: What is the evolutionary history of the behaviour? Function: How does the behaviour contribute to survival and reproduction (fitness)?

PROXIMATE ULTIMATE

Fixed Action Patterns (FAP) Type of animal behavior Sequence of unlearned behavioral acts,essentially unchangeable Once initiated, usually carried to completion Triggered by an external sensory stimulus: sign stimulus

Proximal Explanation: Ultimate Explanation: Ex. Male stickleback fish attacks other male sticklebacks that invade its nesting territory Stimulus=red underside of intruder Proximal Explanation: red belly  sign stimulus  releases aggression Ultimate Explanation: chasing away other fish  decreases chances of eggs being fertilized by another male

Imprinting Type of behavior including learning & innate components irreversible Has a sensitive period; limited phase Where bahaviour can be learned Example: young geese following mom

Behavioural Traits results of complex interactions of: genetic factors (nature) environmental factors (nurture) “NATURE VS. NURTURE”

Innate behaviour Behaviour that is developmentally fixed Under strong genetic influence Ex. Suckling, hunting instincts

Directed Movements: Many animal movements are influenced by genetics… Kinesis (non-directional response) change in activity / turning rate in response to a stimulus ex. Pill bugs are more active in dry vs. moiste area Taxis (directional response) Automatic/ oriented movement toward/away a stimulus ex. trout facing toward the current in direction of food

Migration Movement of animals over a long distance Research shows that migration is under genetic control and follows a polygenic inheritance pattern

Animal Communications & Signals SIGNAL= a behavior that causes a change in another animals behavior Animal communication is due to genetics & environment Animals communicate through visual, auditory, chemical, tactile & electrical signals

Chemical Communication Animals secrete chemical substances called Pheromones ( relates to reproductive behaviours) Phermones are effective at low con’c EX.. Canadian lynx urinates on trees and may leave claw marks to mark territory EX. Male drones attracted to queen bee pheromones outside the hive

Auditory Communication Mating rituals in insects and birds include characteristic song that are under strong genetic control/selective pressure EX: Drosophila’s mating song http://www.youtube.com/watch?v=KzWI uhXMUko&feature=relmfu

Prairie Voles & Genetic Influences Prairie voles are monogamous ( only 3% of mammalian species) Male P.V. help mates care for young-this is relatively uncommon Monogamous prairie voles Neurotransmitter(AVP) released during mating mediating pair-bond formation &aggression Produces feelings of pleasure and make them “addicted” to partner Promiscuous montane voles Different distribution of brain receptor Do not have same feelings of pleasure

Environmental Influences on Behaviour Diet plays an importance role in mate selection Social Environment can influence the way animals behave( ie. Aggressive Behaviour) Learning

Learning- Habituation A loss of responsiveness to unimportant stimuli EX: animals stop responding to signals when signals are not followed by predator attack the “cry-wolf” effect

Spatial Learning Modification of behavior based on experience with spatial structure of environment (ie.nests, hazards, food, mates) EX: Digger wasps found nest entrances by using landmarks (Tinbergen experiment)

Associative Learning Ability to learn to associate one stimulus with another A.k.a.classical conditioning This type of learning plays an important role in helping animals avoid predators

Classical Conditioning An animal learns to associate one of its own behaviours with a reward/punishment Pavlov’s Theory

Operant Conditioning A.k.a. “trial and error learning” Animals are given reward/ punishment for behavior Skinner’s Box experiment

Learning Videos Skinner’s box https://www.youtube.com/watch?v=tWtvrPTbQ_c Pavlov’s Theory https://www.youtube.com/watch?v=qG2SwE_6uVM