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Ethology and Animal Behavior
Chapter 24
• Behavior – way a whole animal reacts to
internal or external stimulus
• Through movements, postures, displays, eating,
eliminating, mating, caregiving, sounds, smells,
hiding, threatening, killing etc.
Behavior
• Behavior
• Varies among species
• Varies among members of same species
• Determines fitness – ability to survive and
reproduce
• Determined by natural selection (at least in part)
Behavior
• Knowledge of behavior
• Important in determining proper management
•eg. piglets nurse more frequently if recorded
sounds of nursing piglets are played
• Human behavior follows many of the same
patterns as animal behavior
Causes of Behavioral
Responses in Animals
• Determined by heredity (internal factors)
• Determined by learning experiences (external
factors)
Causes of Behavioral
Responses in Animals
• Hereditary influences
• Breeds selected for certain behaviors
•eg. horses selected for work, running, draft etc
•No one breed excels in all behaviors
Innate Behavioral Patterns
• Evidence that behavior has genetic basis
• Selection to develop breeds with unique behavior
• Animals show behavior pattern unique to their
breed even if reared artificially
• Some behaviors segregate in Mendelian fashion
Innate Behavioral Patterns
• Thresholds
• Level of stimulus needed to display a behavior
• Some lines have very low threshold (eg fighting
dogs will fight at small provocation)
Innate Behavioral Patterns
• Direct hereditary influences on behavior
• Heredity affects organ size and response
• Heredity affects enzymes and hormones
• Both vary widely among lines with different
behaviors
Experience and Learning
• Behavior based on instincts and reflexes
• Behavior expands or contracts from instinct
due to experiences
• Habituation
• Animals develop habits quickly if experiences
direct that development in a consistent manner
Experience and Learning
• Conditioning
• Classical conditioning (associative learning
• response to previously neutral stimulus
• Pavlov’s dogs
• provided a sound whenever fed
• would start to salivate just from the sound
• Dairy cows start to “let down” milk just from
being let into milking parlor
Experience and Learning
• Conditioning
• Operant conditioning
• response to positive or negative reinforcement
• horse receives treat when performing a trick
• will do trick whenever offered the treat
• animals stay away from electric fence after shock
experiences
Experience and Learning
• Insight learning (reasoning)
• Ability to respond correctly at a new experience
• Early malnutrition appears to interfere with
reasoning ability
Experience and Learning
• Imprinting
• Newly hatched duckling will adopt any moving
object as its parent
• Can be accomplished only very early in life
Intelligence
• Organization of behavior
• Varies widely between and within species
• Conventional wisdom is that mammals are
more intelligent than non-mammals
• Order of mammalian intelligence
• Primates – monkeys, chimps, gorillas, humans
• Ocean mammals – whales, dolphins
• Carnivores – dogs, cats
• Ungulates – pigs, horses, cattle, sheep etc
Motivation
• Internal state of animal which drives it to
behave a certain way
• Hypothalamus controls several types of behavior
• appetite
• sexual behavior
Animal Communication
• Sounds
• Animals will respond to call of distress
• from offspring
• from another member of their species
• Some species emit radar type sounds
• bats, dolphins
Animal Communication
• Chemicals
• Pheromones
• chemical substance that attracts others
• many species – pheromones used to attract mate
• Urine or feces used to “mark” territory
Animal Communication
• Visual displays
• Many birds – use wing or feather displays in
courtship
• Many mammals – raise hair on neck when fearful
• Honeybees – workers use a dance to indicate food
supply
Orientation Behavior (Homing)
• Many anecdotes
• About dogs, cats etc – find way home over long
distance
• Salmon
• Hatched in freshwater stream
• Swim to ocean
• Return to same stream to spawn
Ingestive Behavior
• Eating and drinking
• First behavior – suckling
• Teeth pattern affects ingestion
• swine and horses have full set of teeth in both jaws
• ruminants – cattle, sheep, goats
• no upper front teeth
Ingestive Behavior
• Ruminant intake
• Food is taken in, chewed, swallowed
• Later is regurgitated and chewed again
• behavior is called “rumination”
• Grazing behavior affects forage and range management
• usually eat more tender parts first
• in overgrazing situation, more palatable plants may be
eliminated
Ingestive Behavior
• Cattle spend 1/3 to ½ of time grazing
• Cattle graze at all hours of day
• Some more at daybreak, late afternoon, just before dark
• Nursing occurs both day and night
• most often at daybreak, midday and dusk
Ingestive Behavior
• Pigs born with tendency to root (dig in soil)
• Will root less if fed well-balanced diet
• If fed a grain and protein supplement separately
• Pigs will come close to balancing their own diet
Eliminative Behavior
• Some animals deposit feces randomly
• Other animals follow a pattern
• Farm animals tend to behave in this area like their
wild ancestors
Eliminative Behavior
• Cattle defecate randomly
• Will lie in feces
• Will avoid eating plants near fecal deposits
• Cattle usually urinate randomly
• Sheep follow similar pattern as cattle
Eliminative Behavior
• Swine are thought by many to be unclean
• Swine actually very clean animals
• Usually deposit feces in a corner
• Frequently deposit feces near source of water
• Proper design of swine pens will promote regular
patterns of defecation and urination
Eliminative Behavior
• Horses will return to a single place for defecation
• Poultry defecate at random, except heavy in
roosting place
• Cats bury feces
• Dogs tend to defecate in specific places
Shelter-Seeking Behavior
• Reasons to seek shelter
• Protection from:
• sun
• wind
• rain
• predators
• insects
Shelter-Seeking Behavior
• Behavior prior to storms
• Cattle will descend from high mountain pastures just
prior to a storm
• Cattle will seek shade during heat of day
• Cows will congregate around water at same time
each day
Shelter-Seeking Behavior
• Swine seek shade or wallow in water when hot
• Need for evaporative cooling
• Swine will sleep huddled together when cold
• Cattle, horses sheep will turn away from storm
• Bison face into a storm
Agonistic (Fighting) Behavior
• Involves:
• Threat
• Aggression
• Submission
• Escape
• Passivity
Agonistic (Fighting) Behavior
• Intact males will fight for mating rights
• Castrated males tend to be docile
• Boars, bulls, rams, stallions that run together from
young age seldom fight
• Dominance order already established
• In large range herds with many bulls
• Bulls with graze together at times with no cows around
Agonistic (Fighting) Behavior
• First introduction of sexually mature males
• Almost always results in a fight
• Serious injuries, seldom death, may occur
• Some breeds of cattle have been selected for
fighting behavior
Sexual Behavior
• Comprises courtship and mating
• Important because necessary to continue species
• Males are highly efficient at detecting estrus (time
of mating receptivity) in females
• Estrus in females also called “heat”
Sexual Behavior
• Estrus (heat) in females
• Sow stands still from person placing hand on rump
• Mare will squeal and urinate in presence of others
• Mares and ewes do not seek males as much as other
species
• Cows and sows will let other females mount
Sexual Behavior
• Males detect female estrus by sight and smell
• Stallion will bite and tease the female
• Boar will nudge the sow around shoulders
• Rooster will spread one wing to ground and
perform a mating dance
Mother-Young Behavior
• Maternal behavior begins at parturition (time of
birth) and continues to weaning
• Cows giving birth
• Will seek seclusion, usually in a depression or trees
• Cow will inspect calf and lick it clean
• Calf stands and starts to nurse after ~ 1 hour
• Cow eats the placenta (so as to not alert predators)
• Cow and calf rejoin herd after 2-4 days
Mother-Young Behavior
• Cow is very possessive throughout nursing period
• Will come to rescue calf very quickly
• Cows identify young primarily by smell
• Sight and sound also contribute to identification
• Time of calf removal in beef herds is very noisy
• Dairy herds – calf is separated in a few days
Mother-Young Behavior
• Sows build nest ~ 18 hours before birth
• Time of farrowing - ~ 4 hours
• A few sows become agitated and kill piglets
• Crossfostering is possible within first few days
• Frequently each piglet adopts a single teat
Mother-Young Behavior
• Sheep behave similarly to cattle in many way
around birth
• Ewes will accept orphan goats to nurse
• Mares also behave in a similar manner
• Mule foals receive as much attention as horse
foals
Investigative (Exploratory) Behavior
• Exploration through:
• Seeing
• Hearing
• Smelling
• Taste
• Touch
Investigative (Exploratory) Behavior
• Most farm animals appear curious
• Will advance on new object looking, listening and
smelling
• Sheep tend to be more timid than cattle or swine
• Will try to return to “flight zone” or area of normal
comfort if startled
Gregarious Behavior
• Species and breeds vary in terms of “flocking”
instinct
• Breeds developed in lush areas tend to be
gregarious (stay together in groups)
• Breeds developed in harsh areas tend to spread
out more
Gregarious Behavior
• Sheep - particularly strong gregarious behavior
• Sheep also follow a leader
• “Judas” goat – goat used to lead lambs to desired
location at a market place
• Swine are gregarious – modern production practices limit
the behavior
• Horses also run in “bands” – useful in training a team for
draft purposes
Social Dominance
• Well organized social rank order
• Prominent in many farm species
• Most obvious when species tends to fight or when
resources are limited
• Especially evident in chickens
• hens will fight to establish the “peck” order
• roosters assume dominance during laying season
Social Dominance
• Advantage – gives mating preference to strongest
males (important for sustaining genetic merit for
strength in a species)
• Disadvantage – weaker individuals are sometimes
deprived of food if it is limited
• Genetic contribution – appears to be moderately
heritable
Population Density and Animal Behavior
• Population density in an area is fairly constant in
many wild species
• Regulators of population size
• Predation
• Starvation
• Accidents
• Parasites
• Disease