Lecture 1 Biology of Animal Behavior 1 4/7/2013 3:55:00 PM
Dr. Connie Soros
Instinctive and Learned Behaviors
Most behaviors have both instinctive and learned components:
o Genetically programmed response
o Complete and functional on first use
o Fixed action patterns-same response over and over again
Often functional-feeding, defense, mating, parental
Repeatable in response to sign stimuli(smiling human
babies, Herring Gull chicks).
Baby smiles because of human eyes.
Herring gull chicks see red spot on beak(stimuli)
and begs for food(response).
Parasitic species releasers. The cuckoo is the
parasite where the sparrow is the parent. The
cuckoo are releasers(exaggerated stimuli) that
pretend to be the sparrow’s chick.
Can modified by experiences (snakes). Food
preferences. Coastal snake eat banana slug. Central
snake do not eat banana slug even though they were
the same species. When the coastal
Genetic basis(snakes). Single gene to not affect. Allelle
affect the enzyme which cause behavior differences.
o Dependent upon particular experience during development
o Adaptive behavior-personal social change in negative
behavior. Starling birds add carrot plant into nest. Why? It is
because by adding carrot plants into nest, they are able to
reduce mites into nest.
o Song birds learn their songs. (experiment by Peter marlow)
o The process of experiences changing behavior:
Learn key features of stimulus during critical period
Often used for parental recognition
Geese (anser anser) and people Lorenze (human) spent time with geese. And normally,
when geese imprint on mother, they try to mate with
geese like mother. When geese imprinted on human,
they try to mate with human because similar to mother
o Classical conditioning
Mental association between unrelated phenomena
Conditioned stimulus(bell), unconditional stimulus
o Operant conditioning
Link voluntary operant with favorable reinforcement
Will press button for food(mouse). Press a lever and
there will be food
How Sheldon gave a cookie to penny everytime she got
an answer right.
o Insight learning
Uses problem solving/reason
Much of the scientific knowledge concerning insight
derives form work on animal behavior conducted on
chimpanzees by psychologist wolfgang kohler.
Hung bananas out of reach, where chimps stacked up
the boxes and used a stick to knock the
banana.(problem solving skills)
Lack of response to unimportant stimuli
Decrease in response to a stimulus after repeated
Example: sea hares (Aplasia sp.) new ring tone,
movement of a toy. When danger comes, they retract
gills. When they touch grass, current, touched
repeatedly, they won’t retract gills that many time.
When you always hear a new ring tone, you get
annoyed, but then you don’t hear it anymore. When you wear a new long sleeves, you don’t notice
throughout the day.
If you took a toy and a baby together. If you move the
toy, the baby will concentrate on the toy because they
think it’s a new toy. If you move the baby, the baby
won’t concentrate on the toy (don’t habituate).
Rodent wouldn’t want to use it’s flight/fight response
every time a bird came over. (hawk vs robin).
Habituation: ignore all the small birds coming by-not
danger. And run when big birds-danger comes by.
Neurophysiology and Behavior
Research in neuroscience has shown that behavioral responses,
whether mostly instinctive or mostly learned, depend on an
elaborate physiological foundation provided by biochemistry and
structure of nerve cells.
Although the anatomical and physiological basis for some behaviors
is present at birth, an individual’s experiences alter the cells of its
nervous system in ways that produce particular patterns of
Clusters of nerve cells called nuclei cause singing behavior in birds
o (male produce beautiful songs)
Behavioral gene expression is due to stimuli. Song nuclei in birds
prepare neural development.
o Example: when zebra finches hear song cues of neighbors,
they habituate and ignore them. When zebra finches hear a
different song cue, they fight the invader.
o Birds use zank enzyme to use audio to identify invader.
Hormones and Behavior
Hormones are chemical signals that can trigger the performance of
specific behaviors by regulating neurons and stimulating endocrine
organ cells to release chemical signals.
Hormones control neural development such as higher vocal center
is less developed unless estrogen are applied.
o So estrogen cause higher vocal voice. In male birds there are
enough estrogen. There is not enough estrogen in females
birds. Genes code for hormone production
o Hormones change gene activity in target cell
o Gene activity change neuron change behavior
o Example: changes in concentration of juvenile hormone over
time, changes task specialization in honeybees. As bee age,
they produce more juvenile hormone, this cause more tasks
of the bee such as leaving the hive. So increase age, increase
juvenile hormone increase leaving hive increase work.
o Sexual development/behavior hormonally controlled.
Different gonadotropin hormone. Increase gonadotropin
hormone, increase aggressive male fish. Lecture 2 Biology of Animal Behavior 2 4/7/2013 3:55:00 PM
Neural Anatomy and Behavior
Some specific behaviors are produced by anatomical structures in
an animal’s nervous system
Information acquired by the senses can be relayed directly to motor
neurons (right to muscles).
Eg. Providing prey animals with behavior that can save them from
attack by predators
Example: touching a hot stove. You automatically move away.
Some environmental stimuli cause direct responses in motor
o Cricket and bat interaction
When cricket hear bat sound waves, it lifts its hind leg
to run away. They have ears on the front leg.
Different stimuli cause different responses
o Fiddler crab elevated eyes.
When the crab see predator above, it activates neuron,
escape response, dash into burrow. When the crab see
things on eye level, there is a different response.
How the experiment done was: a black square above
the crab (cause a escape behavior. A black square
below (no response).
Brain anatomy structure is tied to its functional response to stimuli
o Star-nosed mole. It has 22 fleshy tentacles covered in
tactile(touch) receptors called Eimer’s organ. It is used to find
food without sight, and locate earthworms with nose.
o Brain anatomy structure is tied to its functional response to
stimuli. The brain contains most cerebral cells devoted to
tentacles and front digging feet.
One individual produce signal, another receives it.
Types of signals:
o Bird songs. Insects and rattle snakes. Pacific herring
communicate with little bursts of gase through the anus. o Stridulation: rub body together to make songs.
o stiped skunk, human facial expression, royal flycatcher,
bioluminescent lure of angler fish, semaphore flags L, peacock
o ant contains glands that release different pheromone to
initiate tasks such as discovering colony or invaders.
o short distances. Friendly bonding between individuals.
Example is macaws removing dirt from feathers for each
o Electric eel has electric organs that release charges of
intensity and used for signal threats, rediness to breed,
Combinations of types
Honeybees: Tactile, acoustical, chemical, visual components.
Round dance of honeybees-found food source and make
Waggle dance, when food is far from the hive.
If the bee dances up the comb, then the food source is
towards the sun. If the bee dances down the comb,
then the food source is away from the sun. If the bee
dances 45’, then the source is 45’ from the sun.
Sometimes the animal itself is the signal.
o Male baboons display dominance. (Mandrillus sphinx).
o The skunk itself too
Language is communication, but not all communication is language.
Language : Syntax and Symbols.
Dances of honeybees are both syntax(order in which information is
presented) and symbols(display that represents something else).
Vervet monkeys have signals to alert others of predators. One
signal for snake, another for leopard.
Chickadees use different alarm calls
Chimpanzees and gorillas are able to use American sign language.
Migration Travel from birth area to distant area and back
Usually seasonal schedule
Example: Artic tern 40000 km (longest animal migration).
1.Piloting uses landmarks. Simplest migration. Instinctive trait.
o grey whales use visual cues along the pacific coastline
o Pacific salmon use olfactory cues to pilot their way from the
ocean back to the stream where they hatch to breed.
2.Compass orientation use to move a particular distance/time
o day-flying migratory birds use Sun position and internal
o Insects use Earth’s magnetic field.
o Indigo Bunting bird uses star as a compass
3.Navigation use compass and mental map Lecture 3 Population Ecology 1 4/7/2013 3:55:00 PM
The science of ecology
Study of interactions between organisms and their environments
o Focuses on undisturbed natural systems (distribution and
abundance of species and how they interact with each other
and the physical environment)
o Considers the effect of human disturbance (development of
conservation plans to stop and repair ecological damage
cause by humans.)
Levels of Organization.(smallest to largest)
1. Organismal ecology- genetic, biochemical, physiological,
morphological and behavioral adaptations to the environment)
2.Population ecology-groups of individuals of the same species that
3. Community ecology-populations of different species that occur
together in one area
4.Ecosystem ecology-how nutrients cycle and energy flows between
the biotic and abiotic community
5. Biosphere-globally. Earth’s crust,water.
Seven characteristics of populations
1.Geographic Range is determined by the boundaries of
Distribution(individuals in the population often live in a specific habitat within
Geographic range: Overall spatial boundaries within which a
Habitat: specific environment in which a population lives, as
characterized by its biotic and abiotic features
Example, a population of snails may inhabit a small tide pool while
a population of marine plankton may occupy an larger area.
(different geographic range, same habitat).
2. Population Density is based on the numbers of individuals per unit area
(Species with large body size have lower population density) (body size
population density). In terms of population density in largest density to lowest density:
body size population density resources to food, water, sunlight
3. Population Dispersion is the Distribution of Individuals in Space
Clumped dispersion is common and occurs in 3 situations
1. When suitable conditions are patchily distributed (example,
2.When social populations live together to cooperate in rearing
offspring, feeding or defending themselves from
predators(example, fish in social groups)
3. When species reproduce by asexual clones (example, aspen trees
and sea anemones).
Uniform distribution can occur when individuals repel one another
or territorial behavior
o Example: creosote bushes take in water and secret toxic
chemical to make it impossible for seedlings to grow.
Allelopathy-the chemical toxic to prevent seedlings to grow
found in uniform dispersion.
Walnut treets/ creosote.
Territorial behavior (birds not allowing others living)
Random distribution tend to be rare in nature, but occurs when
environmental conditions do not vary much within a habitat and
individuals are neither attracted or repelled by others.
o Example: spiders, clams, rainforest trees.
4. Age structure is the numbers of individuals of different ages (A statistical
description of the relative numbers of individuals in different age classes)
Prereproductive (younger than age of sexual maturity
Postreproductive (older than the maximum age of reproduction)
Population’s age structure reflect its recent growth and predict
5. Generation time is the average time between birth and death.
body sizetime among bacteria, protist, plants, animals.
6. Sex ratio: females: males In general, number of females has a greater impact than males.
The presence of male have little effect on size of future generations
because only females can reproduce.
7. Proportion of individuals that are reproducing (This issue is particularly
relevant to conservation of any species in which individuals are rare or
widely dispersed in the habitat)
Statistical study of processes that change a population’s size and
density through time
Population growth factors: birth and immigration
Population decline factors: death and emigration
Ecologists use demographic analysis to predict population’s growth.
(example, for humans to predict for social services; for animals to
predict for protecting endangered species)
Summarize demographics of population
Age –specific mortality (proportions of individuals alive and when
they die). I am alive from 1-18.
o Number of dying/number alive
Age-specific survivorship(proportions of individuals alive and when
they survived). I have survived from 1-20
o Mortality and survivorship are opposites. The number
difference is 1.
o 1-number of dying /number alive
Age-specific fecundity(the average number of offspring produced by
surviving females during age interval). I have survived from 1-14
and had 1 kid.
Cohort- group of individuals of same age.
Life table will monitor survival of a cohort from birth until all
It shows the number of individuals in each age group.
Survivorship curves Survivorship curves graphically depict the rate of survival for
individuals over the species’ average lifespan(timing of death of
individuals in a population).
1. Type 1 survivorship curve.
o High survivorship until late in life
o example: lamb
o mammals, humans.
o Parental care in early life
2. Type 2 survivorship curve
o constant rate of mortality in all age classes
o example: lizard, small mammals, songbirds.
o Vulnerable to starvation, predation, disease.
3. Type 3 Survivorship curve
o high juvenile mortality, followed by low mortality after critical
age and size.
o Example: tree and shrubs
o fish insects
o produce small but many offspring
o no parental care.
o Logarithmic scale. Lecture 4 Population Ecology 2
(intraspecific) 4/7/2013 3:55:00 PM
Evolution of Life history
Analysis of life tables and survival curves reveal how natural
selection affects an organism’s Life history.
Life history include patterns of
o Maintenance (preservation of good health)
Allocation of resources (finite energy budget-total amount of energy
the organism can accumulate and use to fuel its activities)
influences evolution of these traits.
Usually adjusted to maximize an individual’s number of surviving
Life History Patterns
Coho salmons(Oncorhynchus kisutch) hatch in stream head waters.
They feed and grow for a year before adulthood and swim to the
ocean. They remain in ocean for 1-2 years and return to the
stream. They use sun compass (pilot), geomagnetic, chemical cues
to return. Males prepare nest and female lay 100-1000 eggs. After
breeding adults dies and no parental care for offspring.
o Type 3 curve. High mortality then low mortality rate.
European red deer (Cervus elaphus) born in spring, young remain
with mother for prenatal care. Female deer begin to breed after
adulthood in the 3 rdyear and produce 1-2 offspring per year until
the 16 year-the maximum lifespan and die.
o Type 1 curve.
Oak trees (Quercus sp.) begin as acorns in summer, remain
inactive until spring. After germinating, the seedling tree grow until
they reach a critical size where they produce 1000 acorns for many
years. Growth and reproduction occur simultaneously throughout
most tree’s life. There is no parental care.
o Type 3 curve.
Fecundity VS Parental Care
Trade-off between fecundity and parental care.
Passive Parental care before offspring born-yolk,endosperm,
nutrient across placenta o 1000 eggs total (ducks)
Active Parental care after offspring born
o Many young-little care
o few young-more care.
How often to breed?
One reproductive episode
o Devotes all stored energy
o Maximum fecundity(ability to give birth)
Multiple reproductive episodes
o Only some energy devoted
o Reproductive and growth=tree
o Reproductive and maintanence-mammals
Age at first reproduction
Early reproduction is favoured:
o If adult survival rate is low
Good chance of leaving some surviving offspring behind
o If animals do not grow larger with age
No need to spend energy to grow
o If larger size does not increase fecundity
Larger does not mean more fertile
Later reproduction is favoured:
o If mature adults survive older age
o If organism grow larger with age
o If larger organism have higher fecundity.
Models of Population growth
Exponential models: when population has unlimited growth
o In bacterial growth, bacteria reproduce by binary fission.
Population double in size each generation.
o Exponential model occurs in bacteria and prokaryotes
o o Exponential Growth model: in animals and plants where birth
increase population, death decrease population. Limited
o ΔN=change in population size
o Δt=time period
o Exponential Growth model 2:unlimited population growth.
o By expressing per capita birth and death rate.
o R=per capita growth rate.
o Zero population growth ZPG: B=D.
when birth rate=death rate.
R is high for animals with short generation (sheep)
R is low for animals with long generation (human)
R is normally 0.4
Logistic model: when population has limited growth
o This is because of finite resource. There is a carrying
capacity-maximum number of individuals an environment can
o Includes effects of resource limitations (intraspecific
o Carrying capacity(K): maximum population size that
environment can sustain. o dN/dt=rmax N(K-N/K)
R when N approaches K.
o Logistic model assumes that R N linearly.
o Logistic model also assumes that N at first but slows when
approaching K. (S shaped)
Limiting Resources and the Logistic Model
The logistic model assumes that vital resources become increasingly
limited as population grows.
Intraspecific competition (within species)
For mobile animals the limiting resources could be
food,water,nesting site, refuge from predators.
For immobile animals the limiting resource would be space
For plans, limiting factors are sunlight, water, inorganic nutrient,
population density, growth rateadult
when resources are in short supply, each individual has less energy
for reproduction. Therefore females in crowded population produce
fewer offspring or offsprings that are less likely to survive.
Human population growth
3 ways humans have avoided the effects of density dependent
1. Humans have expanded geographic range, reducing competition
2. Increase K in habitats by hunting, gather, agriculture.
3. Advances in public health, medicine, sewage treatment, food
It has caused us into an exponential curve where B=D
Density independent:B and D do not change
Density dependent: B and D increase . Lecture 5 Population Interactions
(interspecific-community) 4/7/2013 3:55:00 PM
Interactions of species (interspecific) form the basis of biotic
communities. They often involve strategies that are:
o Antagonistic: finding food, avoiding being eaten
o Mutualistic: pollination of flowers
Competition of resources may occur within and between species.
o Benefit, harm, neutral.
1. Predation+/- predator gain, prey killed
2.Herbivory +/- herbivore gain, plants killed
3. Competition -/- both population lose resource.
4.Commensalism +/0 one benefit, other unaffected (elephant
stepping on grass. Elephant unaffected. Grass prey exposed to
5.Mutualism +/+ both benefit (bee and flower)
6.Parasitism +/- parasite gain, host killed (cuckoo parasite and
hedge sparrow host)
Genetically based reciprocal adaptation in two or more interacting
Individuals in one species become better adapted when another
species exerts pressure on that species. This puts pressure.
o Example: cheetah and antelope. Faster cheetah get prey.
o Example: bumblebee and flower
Predation: interaction between predatory animals and the animal
o Carnivores use sensory systems to locate, capture, consume
Example: Rattlesnake has heat sensor on pits of their
face to detect warm blooded prey. They inject venom
(neurotoxin and protease). Once the venom takes
effect, the snake use chemical sensors to follow the
scent trail of dying prey. Example: Vampire bat use noseleaf to find prey. It has
anticlotting chemical in saliva.
Herbivory: interaction between herbivorous animals and the plants
o Use sensory systems to identify food or avoid toxic food.
o Have different teeth system to grind food.
Adaptations for feeding.
Optimal foraging theory (diet)
o Mathematical models that predict an animal’s diet
o Diet is compromise between cost and benefits associated with
different types food.
o Ratio of costs of obtaining the food (time and energy it take
to pursue, capture, consume)VS benefits of consuming
(energy in food).
Affects of Prey density.
When bluegill sunfishes were offered equal number of sized prey
(Daphnia) they always chose the largest prey because large prey
easily found in high density.
o density of L, M, S prey. Fish choose L prey
o density of L, M, S prey. Fish chose L, M, S prey. (equal)
if it can choose based on large density, it will choose
the prey with largest energy (largest Size prey)
Man O War (physalia physalis) jellyfish has stinging cells called
nematocysts and toxic protein and 7 injurious enzymes. (toxic to
o 1. Size
too small/big to be seen as food (elephant)
o 2. Vigilance
sharp lookout for predators and live in groups.
o 3. Freeze and Camouflage
zebra stripes, stick insects, caterpillars that look like
o 4. Evasive action run away or take refuge. (tortoise retreat into rocks).
If cornered by predators, they may try to attack or
startle predators. (not a good defense because they get
close with predators)
o 5. Spines and Armors
cowhorn euphorb, thorns, spiny ant eater, porcupine,
o 6. Chemical
Smelling/tasting bad, toxin, vomit at attackers, spray
chemicals. Become poisonous(monarch butterflies eat a
poisonous plant which makes them poisonous
o 7. Warnings
Aposematic-poisonous or repellant species may
advertise their unpalability. (a red colored
o 8. Mimicry
Batesian mimicry-when drone fly(Eristalis tenax) mimic
the stining honeybee (apic mellifera)
Mullerian mimicry-when butterfly(heliconius errata) look
like butterfly (Heliconius melpomene).
Defence Strategies: no perfect defence
Predators may evolve adaptations to counter prey defences
Example: a beetle spray chemical from hind end. An experience
mice may turn the beetle upside down and eat the head first,
avoiding the hind end. (smart!) 7+2=9 :D it’s a mouse! Lecture 6 Community Ecology
Interspecific 4/7/2013 3:55:00 PM
Competition between species
Can experience: increased mortality, decreased reproduction,
reduction in the size and growth rate of populations.
Two or more populations using same limiting resources
Interference competition (direct)
o One species harms another species directly (lion chasing
prey; creosote bushes releasing chemicals to soil preventing
Exploitative competition (indirect)-first come first serve.
o Two or more population using same limiting resources
o One species reduces resource availability to others (one
species eat seeds, depleting food supply available for other
species to eat seed) (squirrel vs squirrel on who can get seed
Example: Balanus and Chthamalus. The balanus(bottom) has the
realized niche while the Chthamus has been limited and in
Example: Eastern White Cedar trees found at cliffs edge because of
Keystone species are species that have greater effect on community
structure than their numbers suggest (eg. Predatory sea stars). Top
carnivore that controls organism beneath it. Keystone-very few
o When remove sea stars keystone species, decrease in
invertebrate/algae because mussels outcompeted the
invertebrates. (Mussel increased and ate all the food of
Competitive Exclusion Principle (one has a advantage)
Competitive exclusion occurs when two species that require
identical resources occur in the same habitat
One species out competes the other that drives it to extinction
because it harvests resource more efficiently and produce more
offspring. (paramecium Aurelia wins paramecisum caudatum.)
Ecological Niche Concept to visualize population’s resource use
Fundamental niche-range of conditions a species could use
Realized niche-range of conditions it actually uses in nature.
Occurs when several sympatric(living in the same place) species
use different resources or the same resources in different ways.
Plant 1 has roots 2m(foxtail). plant 2 has roots 6m (mallow). plant
3 has roots 10m(smartweed). This allows the plants to live
Allopatric species live in different places.
Interactive vs Individualistic hypotheses of species Distribution
Interactive hypothesis predicts that species have similar distribution
with environment. Each line is a species. They have reduced
abundance at the same spot. Similar niche, and competing against
Individualistic hypothesis predicts that species do not have similar
distribution with environment.
o Most gradient supports individualistic. Reason how they are
able to survive together. They carved out their own realized
niche to be able to survive together.
The borders between communities.
Different soil type, moisture levels.
Adjacent communities often grade into each other or sharp
boundaries occur between communities when a critical resource or
important abiotic factor is discontinuous.
The borders that separates plant 1,2,3,4 are ecotones.
Community characteristics Example: Tropical forest warm moist environment supports
complex vegetation with vertical layers and have high structural
o Canopy>understory>Herb layer (different trees)
o Epiphyte>Liana>Buttress. (different tree structure)
Example: mountainside cold winds and rocks
Measuring Species Diversity(how many different type of tree) and
Evenness(how many). (Shannon researcher)
The value of H’ and Eh provide an indication of the diversity of
forests and evenness.
H’ means few species (diversity) (1A tree 4B tree)
EH means uneven distribution. (evenness) (1A tree 1 B tree)
H’EH means many species and evenly distributed. (1.0 EH is
o Capture sunlight and convert it to chemical energy,
o Primary consumers are herbivores
o Secondary/tertiary consumers are carnivores/omnivores.
o Scavengers(fungi, bacteria, earthworm, vultures) ingest dead
o Decomposers are TYPE OF DETRITIVORE(bacteria and fungi)
Feed on dead organic matter.
o Both detritivore and decomposer reduce organic material into
small inorganic molecules that producers can absorb.
Food chains and webs (One cycle)
Ecologist use food chains/web to illustrate the trophic structure of a
Generally, communities that support complex food webs are more
stable because disappearance of 1 species do not have major
impact on food web.
Food cycle MUST INCLUCDE DETRITIVORES, to break down the
nitrogen. (food web + detritivore=food cycle). Ecological Succession
Somewhat predictable change in species composition over time
Primary succession begins on habitats without soil.
o Glaciation and permafrost
o Volcanic areas
o Dirt, rock (10 years after glaciation)
o First thing that comes in are LICHENS and MOSS (half plant)
They have symbiosis with nitrogen fixing bacteria.