ANIMAL BEHAVIOR Red fire ant queen & worker attendants. Chapter 41

Ethology - the study of animal behavior. Ethologists are particularly interested in adaptive behaviors. Some adaptive behaviors are primarily innate, while others are primarily learned. Ethology officially recognized in 1973 when Karl von Frisch, Konrad Lorenz & Niko Tinbergen won a Nobel Prize. Adaptive behaviors are those that confer some advantage in reproduction or survival.

A. Innate Behavior Inborn behavior that is largely genetically determined. Ex. escape or defensive behaviors Many innate behaviors are stereotyped (all members of a species perform the behavior identically). Stereotyped behavioral sequences are called fixed action patterns (FAPs). Ex. egg retrieving behavior of graylag goose

If egg is removed after goose started moving it, she will continue to roll the “imaginary” egg until it is back in her nest. Once begun, FAPs continue to completion, even without appropriate feedback.

auditory (sounds of mosquitoes & crickets) FAPs are triggered by a specific stimulus called the releaser (sign stimulus). What is releaser for graylag goose egg retrieval? Releasers can be: visual (red underbelly of stickleback fish; light flashes of fireflies; gaping mouth of baby birds) auditory (sounds of mosquitoes & crickets) tactile (male prodding of female stickleback) chemical (pheromones) Releaser for graylag goose is an egg, or other round object, near the nest.

Supernormal releaser - a model that exaggerates a releaser; elicits a stronger response than does the natural object. Herring gull chicks obtain food from their mother by pecking on her bill. Normal releaser is red spot on an oblong object. Supernormal releaser for greylag goose is a basketball near the nest. Basketball triggers egg retrieval behaviors. Supernormal releaser is an oblong object that is totally red or has red stripes.

B. Learned Behavior Behavior modified by experience. Types of Learning: 1. Habituation (simplest form) Animal learns to ignore irrelevant stimuli. Young chicks learn to ignore falling leaves & silhouettes of non-predatory birds. Birds learn to ignore scarecrow. Mothers learn to ignore noisy children.

2. Classical Conditioning Animal learns to associate a new stimulus (conditioned stimulus) with a reward or punishment. Dog associates the sound of a bell with food. [Pavlov’s dogs] Ducks associate people with food. Bears associate cars with food. Extinction - loss of a conditioned response.

3. Operant Conditioning (trial-and-error) Animal learns to associate one of its own behaviors with a reward (positive reinforcement) or punishment (negative reinforcement). Used extensively by animal trainers. Coyote learns to avoid porcupines. Rat learns to press a lever to obtain food. Operant conditioning does have limitations - animals cannot be trained to accomplish tasks that are physically impossible (pig inserting a coin into a slot). Parrot learns to ride a scooter.

Animal learns during a limited time period (critical period). 4. Imprinting Animal learns during a limited time period (critical period). Newly hatched chicks, goslings or ducklings learn to identify the first moving object they see as “mother”. (Konrad Lorenz) Baby birds learn species-specific songs. Mother goat learns to identify her kid’s odor. Long range problems occur if goslings do not imprint on the “proper” mother. They use their mother as a model to locate mates when they become sexually mature. Goslings that imprint on humans seek humans as mates. Mother goat will accept & nurse any young that she smelled during the critical period after she gives birth. She will reject any young whose odor she does not recognize.

5. Insight Learning (reasoning) Animal applies prior learning to new situations without trial-and-error activities. Rare; seen mostly in primates. Chimpanzee figures out how to stack boxes to reach bananas hanging from the ceiling. Human child figures out how to build a vehicle by placing a box on roller skates.

6. Latent Learning Animal uses past observations to perform a new activity; occurs without obvious punishment or reward. Rats learn to negotiate a maze more rapidly if they’ve been previously exposed to it. Wild animals learn details of their range during daily explorations. Predators learn hunting tactics by observing their mother. Wild animals make use of latent learning to quickly find hiding places when a predator strikes.

1. Orientation and Navigation Most animal behaviors have both genetic (nature) and environmental (nurture) components. C. Types of Behavior 1. Orientation and Navigation Many animals orient (move in a specific direction) and navigate (follow a specific course). Male moths flying toward pheromone-releasing females. Bees flying to & from nectar sources.

The most complex orientation & navigation behaviors are seen in migrating animals. Migration – a regularly repeated journey from one specific geographic region to another. Migrations are usually seasonal. Studies indicate that migration among green turtles is primarily learned, while that of some shorebirds is largely innate (chicks can make the journey even when adults are not present). Other migrating animals include insects (monarch butterflies), fish (salmon), and mammals (wolves, deer, bears, whales). Bird migrations

Most migrating species use environmental cues for orientation & navigation. sun & stars earth’s magnetic field sounds, odors, landmarks

Common among insects, birds & mammals. 2. Aggression Often displayed when individuals are competing for the same resources (mates, food, shelter, nesting sites). Aggression is minimized by territoriality and dominance hierarchies. Territoriality - behavior that defends one’s territory. Common among insects, birds & mammals. Fighting to the death is rare in nature because the victor as well as the vanquished may be harmed in a way that reduces fitness. Most aggressive acts involve exaggerated posturing or ritualistic behaviors that resolve the problem before violent conflict ensues.

Ownership is displayed by marking boundaries: Territories can be: large or small defended against all members of the species or members of one sex defended year round or seasonally Ownership is displayed by marking boundaries: pheromones scent glands urine dung

Common among vertebrates (domestic hens, wolves). Dominance hierarchy - a social ranking of adult members of the same sex. Common among vertebrates (domestic hens, wolves). Aggression is minimized because each member in the group knows its place. Dog on left is showing submission (exposing its underside).

3. Mating Behavior Many animals have elaborate, species- specific courtship displays (prevents interspecific mating). Bewick’s swans - male rises up & flaps wings as a prelude to mating. King penguins - male & female “neck” prior to mating. Fireflies - males & females flash species-specific codes prior to mating. Scorpion flies - males must present a gift (food) of suitable size before the female allows him to mate with her. If the package is too small, she will reject him.

Ex. elephant shrews & Bewick’s swans Mating Systems: Monogamy - male & female are paired for a period of time (days, season, lifetime); tend to care for & protect young. Ex. elephant shrews & Bewick’s swans Polygamy - member of one sex mates with several members of opposite sex; members are usually sexually dimorphic. polygyny - 1  / many ’s polyandry - 1  / many ‘s polygynandry - both sexes have multiple partners. Polygyny is most common type of polygamy. Sexual dimorphism - males differ greatly from females in appearance.

4. Altruism Behavior that increases another’s fitness at the expense of one’s own fitness; frequently seen in complex social groups (honeybees, naked mole rats). Altruism is explained by kin selection. By helping a relative survive and reproduce, the altruistic member ensures that some of their genes are passed to the next generation. Fitness - ability to pass genes to the next generation. An individual shares half its genes with siblings, and one-eighth with first cousins.

D. Group Living Many animals live in groups. Advantages Disadvantages conserve heat or moisture better defense (confusion, mobbing) enhanced reproductive success improved food acquisition improved learning Disadvantages rapid depletion of limited food supply spread of disease

Eusocial animals exhibit 4 characteristics: cooperative care of young overlapping generations division of labor communication chemical (alarm pheromone of ants) auditory (sperm whales; elephants) tactile (grooming behaviors of nonhuman primates) visual (round & waggle dances of honeybees) Some elephant sounds are infrasonic (frequencies below the level of human hearing).

Round dance indicates that food is close to the hive. Waggle dance indicates that food is far away: orientation of the “run” relates direction frequency of waggles relates distance 1. Fly toward the sun. 2. Fly away from the sun. 3. Fly at a 45o angle from the sun. Dancing bees that waggle their abdomens very slowly along the straight “run” are telling forager bees that the food source is very far away.

Examples of eusocial animals: Snapping shrimp Snapping shrimp - tiny crustaceans living in cavities of two types of sponges (found in Caribbean coral reefs). Each colony has 1 reproductive female. Snapping shrimp are the first eusocial invertebrate discovered in marine environment. Naked mole rats - inhabit subterranean tunnels in Kenya, Ethiopia & Somalia. Each colony has 1 reproductive female. Youngest members are “janitors”. Oldest members are “sentinels”. Other members are “diggers”, “kickers”, and “food carriers”. Colony is greatly disrupted if queen is removed. Honeybees - live in hives. Each colony has 1 reproductive female; fertilized eggs develop into female workers, unfertilized eggs develop into male drones. Youngest workers are feeders. Oldest workers are foragers. Other members make wax cells or are undertakers. If queen is removed, workers begin feeding several female larvae “royal jelly”. First to emerge becomes queen & kills the others. Honeybees Naked mole rats