Behavior is Adaptive Stimulus (pl stimuli) = information that can make an organism change its behavior. Internal stimuli = tells an animal what is happening inside its body External stimuli = gives an organism information about its environment

Behavior is a homeostatic mechanism (Homeostasis = remaining the same) Examples: Kinesis (random movement until a good environment is reached) Taxis (movement in a specific direction either towards stimuli or away from it) Both behaviors cause an animal to go from a less desirable area to a more desirable

Internal and External Stimuli usually Interact Circadian rhythm = daily cycle of activity that occurs over 24hrs Biological clock = internal mechanism that controls circadian rhythm The pineal gland produces melatonin which detects changes in light Example of something functioning on circadian rhythm is sleep

Hibernation Some animals enter a dormant state during the winter External factors trigger when they enter and leave it Why Hibernate? How does climate change affect hibernators?

Innate Behavior = a behavior that is performed correctly the first time When exposed to the right stimuli (a releaser) the innate behavior is performed = Instinct If the stimuli is constant it may be ignored and the behavior is stopped =Habituation Examples: sea turtles going to the ocean, gulls pecking the red dot, adult birds feeding the open mouth, human babies grasping, mammals suckling

Learning Imprinting = rapid, irreversible process only occurs during a short time Filial and sexual in birds Associative = connect a specific action with a consequence Associative example bird and lady bug

Classical Conditioning = a neutral stimulus causes a behavior that was triggered by another stimulus

Operant Conditioning = specific behavior is increased by positive reinforcement Or specific behavior is decreased by negative reinforcement

Behavioral Costs Energy Cost = takes energy away from other things Opportunity Cost = behavior takes away time from other things Risk Cost = increases possible injury or death Territorial costs vs benefits Optimal foraging = more calories/cost birds given a choice of size of food mussels don’t take the largest

Social Behavior Living in groups Benefits = Costs =

Altruism and Eusocial behavior Altruism = risking its own life for others that are not directly related How could this evolve? Inclusive fitness Kin Selection Eusocial = species live in large group most are nonreproductive, work together