Option A6: Ethology Info pulled from Biology for the IB Diploma Exam Preparation Guide Walpole Cambridge University Press

Ethology The study of animal behavior in natural conditions (natural environment, habitat, etc). Behavior is the pattern of responses of an animal to one or more stimuli

Natural Selection Survival of the fittest – Fitness deals with an organisms ability to adapt over time to environmental changes. – Organisms best suited for their environments will have the highest fitness. – More likely to survive, reproduce and pass on their gene pool.

Blackcaps Migration Changes Songbirds Migratory behavior has changed over time Some modified their migration so that they winter over the UK instead of in Spain This way they are able to more quickly return to their summer breeding grounds in Germany & occupy the best nesting locations. By experimenting with the eggs from the birds in Spain and the UK, scientists have shown the migratory differences are inherited.

Innate and Learned Behaviors Be familiar with the following examples

Synchronized estrus in lions Within a pride, female lions come into estrus and are ready to mate at the same time Synchronized estrus produces cubs that are born at the same time and so can be suckled and protected by more than one female in the pride

Breeding strategies in coho salmon Males adopt one of 2 strategies in their mating behavior – Mature early at a smaller body size (jacks) or delay maturation until larger (hooknoses) – Hooknoses fight for access to females but jacks avoid fighting and sneak up on females to mate

Mate selection in birds of paradise Males of many species of the bird of paradise have elaborate plumage and complex mating displays Females watch the displays and select a mate from the quality of the display

Vampire bats – evolution of altruistic behavior Altruistic behavior = unselfish behavior that does not benefit the individual itself but benefits another Female bats that have fed and return to their colony will regurgitate the food into the mouth of a bat that has been unable to feed and might otherwise die

Foraging in shore crabs Hunting and foraging has an energy cost (finding, catching, consuming food) that has to be balanced with energy the animal gains Crabs are able to change their behavior to ensure the overall benefit is greater than the cost as they feed on mussels

Blue tits and cream Blue tits learn a new behavior feeding on cream from milk bottles and also passed on the skill to other members of their species This behavior has largely been lost today as milk is not sold in bottles, but in cartons from a supermarket

Innate behavior Only modified by natural selection – Occurs slowly because requires new variations in allele frequencies that affect behavior – Learned behavior takes time to be learned but can spread rapidly in a population as individuals learn from one another – Learned behavior is much more adaptable and produces a greater range of behavioral patterns than innate behavior