Animal Behavior

Behavior

• Behavior is action that alters the relationship between an organism and its environment

• Results from:– An external stimulus (being chased)– Internal stimulus (hunger)– A mixture of the two

• Distinguished between two types: Innate and Learned

Innate Behavior• Determined by the

nervous system• Inflexible-a given

stimulus triggers a given response

• Examples include– Taxes– Reflexes– Instincts– Migration,

estivation, and hibernation

Taxes

• The response to a stimulus by automatically moving directly toward or away from it

• Three main types– Chemotaxis– Phototaxis– Magnetotaxis

Chemotaxis

• A phenomenon in which body cells, bacteria and other organisms direct their movements according to certain chemicals in the environment

• Ex:– This is important for bacteria to find food,

usually glucose, by swimming towards the highest concentration of food molecules

Phototaxis

• A type of taxis that occurs when a whole organism moves in response to the stimulus light

• It is considered positive when the organisms moves toward the light and negative when it moves away

• Example:– Phototrophic organisms can orient

themselves most efficiently to receive light for photosynthesis

Magnetotaxis

• The ability of certain bacteria to sense a magnetic field and coordinate their movement in response

• The bacteria contain internal structures known as magnetosomes

Withdrawal Reflexes

• An example would be touching a hot object then quickly pulling away

• The steps are as follows:– The stimulus (heat) is detected by receptors

in the skin– These initiate nerve impulses in sensory

neurons and go from receptors to the spinal cord

– The impulses go from the spinal cord to the nerves that triggers the flexors in your hand (muscles that make your hand move) to withdrawal

Instincts• Complex behavioral patterns that you are

born with, are inflexible and extremely valuable at adapting the animal to its environment

• Much more complex than reflexes

• The entire body participates in the behavior– Ex: suckling

Migration

• The movement of animals to a place that offers better living conditions

• Many animals migrate to avoid unfavorable changes in the weather or better food supply

Estivation

• A dormant (sleeping) state that occurs in the life of some animals during hot, dry periods

• When animals estivate, their breathing, heartbeat and other processes slow down which decreases the amount of water needed

• Many amphibians and reptiles do this

Hibernation

• An inactive, sleeplike state that some animals enter into during the winter months

• The animal’s body temperature is lower than normal, heartbeat and breathing slow down greatly

• These animals need little energy and live off fat stored in its body

Learned Behavior

• Behavior that is altered as a result of an experience of an individual

• Various types which include:– Habituation– Imprinting– Classical conditioning– Trial and error

Habituation

• The reduction in a previously displayed response when no reward or punishment follows

• This lack of response is not due to fatigue and is long lasting– Ex: you make an unusual noise in the

presence of your dog and he turns his head, if nothing happens when he does so, eventually he will no longer look at you

Imprinting

• Learning that occurs at a particular age or a particular life stage, and usually at a very young age

• It is rapid and apparently independent of the consequences of behavior

• Know to follow first thing they see, but do not know what it looks like

Classical Conditioning

• Sometimes referred to as the conditioned response

• The simplest form of learned behavior

• It is a response that comes to be caused by a stimulus different from the one that originally triggered it

• The best known example is Pavlov’s dogs

Ivan Pavlov• He found that by placing meat

powder in a dog’s mouth, it would cause the dog’s mouth to salivate (spit buildup)

• The meat powder is known as an unconditioned stimulus (UR), it then triggers the salivary glands to produce spit, known as the unconditioned response (UR)

• Pavlov rang a bell every time he put meat powder in the dog’s mouth, overtime, the dogs would salivate upon hearing the bell alone (even with no meat powder present) this is known as the conditioned response (CR)

Trial and Error

• Also known as instrumental conditioning

• Deals with the changing of behavior, voluntarily

• The behavior operates on the environment and is maintained by its consequences

Social Behavior

• Behavior directed towards, or taking place between, members of the same species

• Many social behaviors are communication, territorial defenses and courtship

Communication With Pheromones

• Chemicals released by an organism into its environment to communicate with other members of its own species

• Most animals use pheromones in some way, one of the most interesting are insects’ use of them– The two most common types of insect

pheromones are the trail and queen mandibular pheromones

Insect Pheromones

• Trail Pheromones– Certain ants lay down

a trail of pheromones as they return to their nest with food

– This allows other ants to be guided back home

– When food supplies run low, ants stop going there, and the trail disappears

• Queen Mandibular Pheromones– In honeybees, the

queen releases pheromones that:

• Induces the workers to feed and groom her

• Inhibits the workers from building queen cells to rear a new queen

• Inhibits ovary development in the worker bees

Social Behavior-Territory

• Territorial Defense: What does it contain that is so valuable?– Food – Mates– Water– Shelter– Nesting sites

Courtship

• Reproductive strategy that helps locate healthy mates