Goal 4 - Behaviors
INNATE BEHAVIORS
(Reading pages 859-867)
A behavior is any thing an animal does in response to a stimulus.
(Reading pages 859-867)
A behavior is any thing an animal does in response to a stimulus.
- A stimulus is an environmental change that directly influences the activity of an organism
- Animals carry on many activities—such as getting food, avoiding predators, caring for young, finding shelter, and attracting mates—that enable them to survive and reproduce
- An animal’s genetic makeup determines how that animal reacts to certain stimuli.
- Often, a behavior exhibited by an animal species is the result of natural selection.
- Individuals with behavior that makes them more successful at surviving and reproducing tend to produce more offspring than individuals without the behavior.
- These offspring will inherit the genetic basis for the successful behavior.
Types of Innate Behaviors
Inherited behavior of animals is called innate (ih NAYT) behavior.
- Through experiments, scientists have found that an animal’s hormonal balance and its nervous system affect how sensitive the individual is to certain stimuli.
- Innate behavior includes fixed-action patterns, automatic responses, and instincts.
Fixed Action Pattern
A fixed-action pattern is an unchangeable behavior pattern that, once initiated, continues until completed (example toad capturing a grasshopper/prey).
Reflex
A reflex (REE fleks) is a simple, automatic response to a stimulus that involves no conscious control.
Fight or Flight
A fight-or-flight response mobilizes the body for greater activity.
- Your body is being prepared to either fight or run from danger.
- A fight-or-flight response is automatic and controlled by hormones and the nervous An instinct (IHN stingt) is a complex pattern of innate behavior.
- system.
Instinct
An instinct (IHN stingt) is a complex pattern of innate behavior.
- Instinctive behavior begins when the animal recognizes a stimulus and continues until all parts of the behavior have been performed (example greylag goose)
Courtship Behaviors
Courtship behavior is the behavior that males and females of a species carry out before mating.
- Like other instinctive behaviors, courtship has evolved through natural selection
- Individuals often can recognize one another by the behavior patterns each performs.
- In courtship, behavior ensures that members of the same species find each other and mate.
Territories
A territory is a physical space an animal defends against other members of its species.
- It may contain the animal’s breeding area, feeding area, and potential mates, or all three.
- Animals that have territories will defend their space by driving away other individuals of the same species.
- Although it may not appear so, setting up territories actually reduces conflicts, controls population growth, and provides for efficient use of environmental resources.
- When animals space themselves out, they don’t compete for the same resources within a limited space
- Pheromones are chemicals that communicate information among individuals of the same species.
- Many animals produce pheromones to mark territorial boundaries.
- One advantage of using pheromones is that they work both day and night, and whether or not the animal that made the mark is present.
Aggressive Behaviors
Aggressive behavior is used to intimidate another animal of the same species.
- Animals fight or threaten one another in order to defend their young, their territory, or a resource such as food.
- Animals of the same species rarely fight to the death. Fights are symbolic.
- The fight is over when the defeated individual shows submission to the victor.
- In animals, usually the oldest or strongest wins the argument.
Dominance Hierachy
A dominance hierarchy (DAH muh nunts · HI rar kee) is a form of social ranking within a group in which some individuals are more subordinate than others.
The ability to form a dominance hierarchy is innate, but the position each animal assumes may be learned.
The ability to form a dominance hierarchy is innate, but the position each animal assumes may be learned.
- The term pecking order comes from a dominance hierarchy that is formed by chickens. The top-ranking chicken can peck any other chicken. The chicken lowest in the hierarchy is pecked at by all the other chickens in the group.
Circadian Rhythms
A 24-hour, light-regulated, sleep/wake cycle of behavior is called a circadian (sur KAY dee uhn) rhythm. Circadian rhythms are controlled by genes, yet are also influenced by factors such as jet lag and shift work.
Migration
Migration, for example, occurs on a seasonal cycle. Migration is the instinctive, seasonal movement of animals. Change in day length is thought to stimulate the onset of migration in the same way that it controls the flowering of plants (photoperiodism).
- Some use the positions of the sun and stars to navigate.
- They may use geographic clues, such as mountain ranges.
- Some bird species seem to be guided by Earth’s magnetic field.
- Young animals may learn when and where to migrate by following their parents.
Hibernation
Hibernation (hi bur NAY shun) is a state in which the body temperature drops substantially, oxygen consumption decreases, and breathing rates decline to a few breaths per minute. Its conserves energy
Estivation
Estivation (es tuh VAY shun) is a state of reduced metabolism that occurs in animals living in conditions of intense heat. Could be due also to lack of food or periods of drought.