Ethology is t he study of animal behavior with emphasis on the behavioral patterns that occur in 

natural environments

One of the fundamental questions of behavior is how much behavior is genetically based, and how 

much is learned, the “nature vs. nurture” debate.

There is a genetic cause for many behaviors, so called innate or instinctual behaviors 

(discussed below).

1. Inbreeding creates lineages with specific behaviors -- fighting in pit bulls, gaited 

horses, draft horses, sled dogs, hygienic bees, etc. 

2. Cross breeding dilutes these behaviors, sometimes along Mendelian ratios if relatively 

few genes are involved (hygienic bees are an example). 

3. Specific genes have been associated with behavior in Drosophila and others. 

1. Rats can be taught to associate certain stimuli with bad tasting food. 

a) A stimulus is presented with a noxious food. 

b) The rat associates the stimulus with the noxious food. 

c) When the stimulus is presented with a preferred food, the food is rejected. 

2. Rats can learn to associate certain smells with noxious foods, but rats never learn to 

associate light with noxious foods -- their physiology predisposes them to specific 

kinds of learning.

Some learning is tied to development, 

i.e. some behaviors can only be learned at specific 

times in development, and development genetically controlled. 

Studies of twins raised in different environments clearly show a strong genetic base for 

“tendencies” in learning and behavior.

1. Learning where to forage for example; i.e. where to find food or prey, water, or shelter 

at specific times of the year. 

2. This type of learning is more typical of animals that have long “childhoods” spent 

with their mother.

 Instinctual Behavior is responsible for some animal behaviors and exhibits the following 

characteristics:

A. Largely genetic. 

B. Triggered by specific stimuli. 

C. Produces specific behaviors. 

D. Does not involve learning.

F. It is thought that there are genetically determined neural networks, called innate releasing 

mechanisms (IRM’s), that when triggered by a sign stimulus, produce a specific behavior 

called a fixed action pattern(FAP).

1. During breeding season red feathers (not another male robin) triggers fighting 

behavior in male European robins. 

2. Sign stimuli, as these examples suggest, can be very specific and do not require a 

whole animal to elicit a response. 

Learning is the process of developing a behavioral response based on experience; there are several 

types of learning

A. One type of learning is Conditioning (Associative learning)

B. Habituation (acclimation/nonassociative learning) is learning not to respond to a stimulus.

C. Latent learning occurs in the absence of an immediate reward.

D. Imprinting is a rapid learning that occurs only at specific stages of development.

E. Insight learning occurs when an animal solves a problem without experience, without trial 

and error, the animal solves the problem or practices trial and error in its mind.

One type of learning is Conditioning (Associative learning)—conditioning has the following 

characteristics.

1. Learned behavioral response to a novel or substituted stimulus. 

2. Uses reward as a basis for learning.

a) Classical Conditioning

b) Operant Conditioning

(1) A stimulus is substituted for one that is already associated with a behavior. 

(2) The reward follows the stimulus. 

(3) The animal learns to associate the new stimulus with the reward. 

(4) Is passive, i.e. the animal does not need to exhibit a behavior to get the 

reward; it learns a new stimulus to trigger the existing behavior. 

(5) Pavlov’s dog experiments is a famous example. 

(a) Dogs salivate when presented with meat. 

(b) Pavlov shined a light (later rang a bell) before giving meat to dogs. 

(c) Dogs eventually salivated in response to the shining light (or bell). 

(d) The dogs were conditioned to salivate to a shining light. 

(1) The animal must perform an act (behavior) in response to a stimulus to get 

the reward. 

(2) The reward follows the behavior, not the stimulus. 

(3) It is an active process; the animal must do something specific to get the 

reward. 

(4) The animal learns to associate the reward with the behavior. 

(5) Virtually all animal training involves operant conditioning. 

(a) The trainer gives a signal, waits for the desired behavior, and 

rewards with affection, food, etc. 

(b) The trainer makes the animal uncomfortable until desired behavior 

displayed and is rewarded with removal of the discomfort. 

(6) Horses instinctually resist pressure. 

(a) Apply pressure to horse. 

(b) Make the pressure uncomfortable. 

(c) Horse moves away from pressure, discomfort removed, becomes the 

reward. 

(d) Repetition conditions the horse to “give” or move away from 

pressure (bit, hand, halter, etc.). 

(7) Most learning in nature is thought to be operant conditioning—behaviors 

such as imitating mother’s predatory behaviors, foraging behaviors, etc. 

lead to food rewards

(1) Generalized conditioning occurs when the animal responds to similar 

stimuli (dog salivates in response to any colored light). 

(2) Discriminating conditioning occurs when animal responds to a specific 

stimulus (dog salivates to blue, but not red light). 

d) One must carefully consider the ethics of behavioral and physiological studies as 

much cruelty has been dispensed on animals in the name of “knowledge,” --that 

may not always be argument enough.

1. Newborn elk, deer, moose are typically very reactive, very jumpy, must learn to NOT 

respond, that is the reward, the absence of fear. 

2. Prey respond to smell, sight, and behavior of predators, but habituate to sight, smell, 

and behavior of nonpredatory species.

1. Rats allowed to wander a maze without a reward, find a reward when presented much 

faster than mice that have never been in the maze. 

2. Animals learn their environment latently as they wander, which may save their lives 

when a predator appears. 

3. Animals transplanted to new areas have high mortality because they are unfamiliar 

with their new territory. 

4. Wolf reintroduction was unsual because mortality was very low; but they had a ready 

and abundant food source to which they were already accustomed.  

5. In capture-release studies it is VERY important to release animals exactly where they 

were captured so they know where shelter, food, etc. can be found—mortality much 

higher is release in unfamiliar territory. 

1. Imprinting occurs by the types of learning discussed already, but is influenced by 

genetics, development, hormones, and other factors. 

2. Ducks and geese will imprint on first moving thing they see after the hatch as mother; 

could be you if you were there at the hatch. 

3. There may be other critical periods as well—for example some GYE songbirds must 

learn mating songs at puberty or they can never be learned.

Insight learning occurs when an animal solves a problem without experience, without trial 

and error, the animal solves the problem or practices trial and error in its mind.

1. Insight learning is considered the domain of higher primates. 

2. Actual trial and error is a type of operant conditioning. 

3. Clark’s nutcracker and Gray Jay seem to exhibit insight and other high level 

intelligence. 

a) They can remember the location and quality (whether high in fats, 

carbohydrates, or protein) of food caches; and will change behavior, exhibiting 

deception, if being watched by another bird—they will pretend to go to a cache. 

b) They are self aware and aware of intentions of others. 

Memory and learning. 

A. Memory is the storage and retrieval of information.

1. The anatomical-physiological change that accompanies learning is known as an 

engram. 

2. There is substantial evidence that we store a tremendous amount of information, but 

retrieval of that information seems to be the limiting factor--subjects under hypnosis, 

or stimulated by electrodes remember distant facts in incredible detail that has been 

verified.

B. There is evidence of at least two memory systems at work in the brain, short-term memory 

and long-term memory.

1. Many experiments support the notion of long and short-term memory--one is 

described below. 

a) Mice were placed in a box with a hole, and were mildly shocked if they went in 

the hole. 

b) The mice avoided the hole. 8

c) If the mice were given an electro convulsive shock within an hour of learning to 

avoid the hole, they would forget, and would again try to enter the hole the next 

day. 

d) If they were given the electro convulsive shock more than two hours after 

learning to avoid the hole, the mice would remember to avoid the hole the next 

day.

2. This and other experiments have led to a consolidation hypothesis, which contains the 

following elements.

a) Information is first stored in short-term memory where its neurological effects 

last about an hour, after which the system will return to normal (one forgets). 

b) Within that hour events are shifted to long-term memory where an engram 

forms--this is known as consolidation. 

c) During consolidation memory is subject to disturbances (inaccuracies), which 

may be so severe as to make the informaton irretrievable. 

a) Short-term memory is thought to be created by “reverberating” circuits of 

neurons. 

b) These circuits include positive feedback loops that increase the activity of 

certain stimuli. 

c) These loops will break down without repeated outside stimuli. 

d) Certain events, especially those that emotionally stimulating, are much more 

likely to be retained in short-term memory and consolidated into long-term 

memory.

a) Evidence shows that at least some memory formation changes neural networks, 

i.e. axons and dendrites change affiliations. 

b) Different kinds of information from a specific event may be stored in different 

parts of the brain, i.e. visual information in the occipital lobes, auditory in the 

temporal lobes, etc. 

c) These memories will be integrated, in as yet, poorly understood processes.

A. Proximate causes are the immediate causes for a behavior -- the sign stimuli, physiological, 

and psychological factors that result in behavior. 

B. Ultimate causes are the evolutionary or adaptive causes for behavior -- what is the benefit to 

an individual or species that makes the genetic base for the behavior accumulate in the 

population.

There are many types of behaviors that are fairly universal, or at least very common among 

animals. 

A. Foraging behavior --the search for food.

B. Communication is an extremely important behavior and is accomplished in many ways.

C. Aggression is an extremely interesting behavior for many reasons.

D. Territorial behavior. 

E. Inactivity.

1. Some animals are generalists able to feed on a variety of food sources, sometimes in a 

variety of habitats -- crows are an example in the avian clade acting as herbivores, 

insectivores, carnivores, and detritivores; grizzlies are another generalist in the 

ecosystem; generalist learn what to eat via learning, instinct is secondary. 

2. Some animals are specialists able to feed on only very specific food items—the black 

footed ferret, while not found in the ecosystem is found in Wyoming and will feed 

ONLY on prairie dogs; this is instinctual although the hunting techniques may be 

learned. 

3. Most specialists have a strong genetic base for their behavior, whereas most 

generalists must learn what to eat from their own experience or be taught by their 

parents. 

a) Grizzly bears are an example of a generalist species that requires parental 

instruction. 

b) Mountain grizzlies feed differently than lowland grizzlies -- if the young are 

driven to new habitats by established bears they will have difficulty surviving, 

and are more likely to have problems with humans.

Communication is an extremely important behavior and is accomplished in many ways.

1. What kinds of things are communicated?

a) Emotional state. 

b) Sexual State. 

c) Identity. 

d) Etc. 

a) Color changes associated with mood changes, estrus, maturity, etc. 

b) Coloration of animals may communicate sex, health, identity, symmetry (and 

attractive quality for mating), and age. 

(1) “Tags” of coloration, emphasize facial or other features important in 

communication. 

(2) Tigers for example have white tags on the back of their ears, these may be 

important in communicating with cubs (who are following the mother) 

when she is stalking prey. 

c) Posture is used by a variety of animals to convey emotional state, health, etc. 

d) Movement likewise can be used to convey emotional state, health, etc. 

e) Eye contact typically conveys hostility or aggression. 

f) Facial expressions are very important among primates.

3. Movement—bobbing heads, swishing tails, stiff posture, nose extended all indicate 

aggression. 

4. Sound of course is also extremely important in communication and is used to convey 

the following. 

a) Many animals exhibit “dialects” in their language -- bird and whale songs vary 

geographically within a species, as do bat echolocation calls. 

b) The ecosystem is alive with sounds from large to small animals—much can be 

learned sometimes by just listening.

a) Pheromones are chemicals produced by one animal that influence the sexual 

behavior of another. 

(1) They are typically associated with sexual behavior -- for example a female 

moose in estrus produces a pheromone that causes urination and 10

aggressive behavior in males, and a pheromone in the urine of the male 

causes ovulation and receptivity in the female. 

(2) Some insects produce pheromones when they reach sexual maturity that 

will accelerate sexual maturity and trigger sexual behavior in the opposite 

sex. 

b) Chemicals can also communicate emotional state (“smelling fear”), and identity 

-- bats identify their own offspring in large colonies, primarily by smell. 

c) Territory is also marked with chemicals: males spray from anal glands or urinate 

on vegetation; they rub on trees to leave behind their odors. 

1. Aggression appears to be highly instinctual and is influenced by a number of triggers 

such as development, hormones, seasonality, pheromones, and visual and auditory 

stimuli. 

2. Intraspecific aggression. 

a) Most intraspecific combat is ritualistic, but it can become truly violent and 

dangerous. 

b) Most intraspecific fighting adaptations, such as deer antlers, are designed to 

prevent injury to self and opponent, rather than cause injury -- the tines of deer 

antlers curve inward and lock together rather than puncture. 

c) Most vertebrates seem to possess some sense of self-awareness. 

(1) Many behaviorists like to consider this a purely human trait, like language, 

but modern research does not support the notion of any behavioral trait 

belonging exclusively to humans. 

(2) Animals seem to be able to “size up” one another, and the smaller or 

weaker invariably concedes. 

(3) Only animals with a realistic chance of succeeding push ritual display and 

mock combat to real combat. 

d) Intraspecific triggers of aggression relate to territorial defense of food and/or 

mating resources. 

e) Males who become haremistic or territorial during their “rut” can be aggressive 

interspecifically as well as intraspecifically.  

a) Predation -- animals kill and eat one another. 

b) Territorial defense of food and mating resources. 

c) Some interspecific aggression is puzzling. 

(1) Wolves run down and kill coyotes but do not eat them, yet do not 

consistently persecute foxes. 

(2) Bull bison are aggressive with all large to moderately sized animals in 

whatever territory they decide to claim—they will move us out; 

pronghorn; elk; deer; etc; they are extremely dangerous, I cannot 

overemphasize the hazard they pose. 

4. Aggression, self-awareness, and individual recognition also relate to social dominance 

hierarchies such as what we see in wolf packs.

a) In dominance hierarchies individuals in a social order have a specific role in 

food gathering, mating, feeding etc. 

b) Aggression is the primary means by which social hierarchies are established and 

maintained. 

c) When adults return to dens with food the pups and subordinate animals take 

submissive postures and beg for food by licking the lips of those carrying food 

in their stomachs—they regurgitate meat for the young and subordinates. 

1. Virtually all animal species defend a territory for food, and mating rights. 

2. This is a problem for young animals as they must either take a territory from an animal 

or find a new territory, difficult to do in world of shrinking natural habitat. 

3. Territorial behavior is genetically based.

1. Hibernation—slowing of metabolism and lowering of body temperature for extended 

periods; associated with winter; examples from the GYE include most rodents, bats, 

and bears. 

2. Dormancy—is a mild slowing of metabolism with frequent arousals for feeding or 

drinking; some rodents, birds, and bats are dormant during the days during summer 

months but arouse in the evenings to feed. 

3. Estivation (Aestivation)—does not occur in the GYE; is reduced activity in times of 

high temperatures; desert animals estivate during the hottest parts of the day; repiles 

must become inactive or will not be able to deliver adequate oxygen to tissues.  

A. Circadian rhythms are 24 hour day-night behavioral and physiological cycles that are 

genetically based for all species -- these rhythms are very difficult to change substantially, or 

for long periods of time.

1. Some species are primarily nocturnal -- active at night. 

2. Some species are primarily diurnal -- active during the day. 

3. Almost all animals are crepuscular—active at dawn and dusk. 

4. Sub cycles exist within these (active before dawn and after dusk, and inactive in the 

midday, for example).

B. Social behaviors are those that permit animals to coexist in groups, with groups of animals 

forming discrete functional entities.

1. To understand chimpanzee behavior, for example, one must study a chimpanzee 

interacting with one another, to quote Jane Goodall, “One chimpanzee is no 

chimpanzee at all.”

(1) Intraspecific cooperation is widespread and generally revolves around one 

of the following. 

(a) Helping one another obtain food (cooperative hunts, sharing food, 

etc.). 

(b) Obtaining mates (protecting the social status of a close relative)—

siblings defend alpha male and females in wolf packs for example. 

(c) Protection (warning of predators, helping in defense of social 

challenges). 

(d) Maintaining health (grooming)—many of the large ruminants groom 

one another. 

(e) Interspecific cooperation also occurs, but is not important to social 

behavior and revolves around the same  

(2) Interspecific cooperation also occurs, but is not important to social 

behavior and typically revolves around one of the following.

(a) Helping one another obtain food (cooperative hunts can occur if one 

species feels it can get left overs from a larger predator). 12

(b) Protection (egrets follow ungulates and eat insects and small animals 

they stir up, yet spook when predators near, warning the ungulates). 

(c) Maintaining health (tick birds and others groom large mammals). 

(1) Altruism is generally observed with relatives. 

(a) Individuals subordinate themselves so that more dominant siblings 

mate—very common in wolf packs. 

(b) This is known as kin selection. 

(i) Ideally one mates to pass on traits. 

(ii) If one cannot mate, however, the next best strategy is to ensure 

that close relatives survive and reproduce. 

(iii) In this way genes you share with relatives may still 

accumulate in the population. 

(2) Altruism is an effective evolutionary strategy in species with social 

hierarchy. 

c) Selfish behavior is one that benefits self at the expense of another, but it is 

antisocial.

1. In the GYE animals migrate in for summer and out for winter—songbirds, sandhill 

cranes, pronghorn, many others. 

2. Cutthroat trout migrate for spawning. 

3. The sun, stars, magnetic fields, food supply, temperature, and smell have been 

implicated as playing a role in navigation in different species. 

D. The mechanisms of species and individual recognition vary widely in animals, yet they are 

virtually universal behaviors that ultimately define a species.

1. Members of the same species recognize their uniqueness from other species in the act 

of mating. 

2. In the wild, members of the same species mate with one another, and do not mate with 

members of different species -- it is this genetic isolation that defines a species. 

3. Visual, auditory, behavioral and chemical stimuli all contribute to species and 

individual recognition. 

4. This recognition is largely instinctual, but environment definitely plays a role -- scarlet 

and green wing macaws look very similar yet never mate in the wild, though if raised 

together from infancy they will imprint on one another and successfully mate. 

5. An extension of individual recognition is kin recognition -- many animals recognize 

kin and bestow upon them special treatment.

1. Behavioral ecologists have always been very careful not to prejudice observations of 

animal behavior with emotion, or confer emotions to animal behavior. 

2. If anything, there has been a traditional prejudice that emotions are the domain of 

humans and not animals -- that animals display behaviors consistent with emotion, but 

that there is no evidence that they actually feel emotions. 

3. The problem with this approach is that it can be applied to humans as well. 

a) The only reason we know humans have emotions is that we can feel them, and 

express them via a complex language. 

b) However, because one person feels emotions does not mean that another person 

feels emotions -- a person may display behaviors consistent with emotions, but 

that does not necessarily mean that person actually is feeling the emotion. 13

c) This is one of the dilemmas faced by jurors judging witness testimony in trials -- 

are the witnesses credible, one judges their behavior, and makes interpretations? 

There is a growing body of researchers, which finds the traditional approach to animal 

emotions flawed. 

a) They tend to interpret behavior consistent with emotion, as evidence of emotion. 

b) They reason that the evidence for evolutionary homology shared by vertebrates 

not only includes anatomy, physiology, genes, and behavior, but extends to 

emotions as well. 

c) It is inconsistent with evolutionary theory to think that behavioral homology 

exists; yet emotions are novel to humans and perhaps the great apes. 

d) Elephants, cetaceans, great apes, dogs, horses and other animals almost certainly 

display emotions. 

5. Ego continues to flaw scientific reasoning, and interpretation of emotion is probably 

one of those last bastions of humanistic egomania. 

1. The gold standard of self perception has been mirror recognition—in other words 

when an animal looks in a mirror does it recognize itself in the mirror. 

2. Very few animals can do this; but many levels of self perception. 

3. In fights or territory animals can size up one another; this requires some self 

awareness; also gray jay cannot be deceptive without some self awareness. 

4. This is an area that is beginning to change.

Another aspect of animal behavior that no longer belongs to humans alone is the concept of 

culture.

1. As mentioned previously many animal languages have been found to have dialects 

specific to certain geographic areas. 

2. Likewise learned behaviors may exist in certain areas and be missing or modified in 

others. 

3. Some examples from chimpanzee cultures. 

a) In one area chimpanzees kill parasites removed from partners after grooming, on 

their forearm before examining them and eating them. 

b) Another culture smashes the parasites on a leaf before examining and eating. 

c) Another kills on a leaf, but does not eat them. 

d) Etc. 

4. A modification of a single act does not a culture make, but an assemblage of 

behavioral modifications, does.