Transcript What is Behavior?

What is Behavior?
Behavior is everything an
animal does and how it
does it.
Ethology is the scientific
study of how animals behave.
The foundations of behavioral
ecology were established by:
•
•
•
von Frisch
Lorenz
Tinbergen
•Behavioral ecologists distinguish
between proximate and ultimate
causes of behavior.
Proximate – focuses on environmental
stimuli that trigger behavior; the “how”
questions.
Ultimate – addresses the evolutionary
significance of a behavior; the “why”
questions (Why did natural selection
favor this behavior?)
Classic Demonstration of Innate
Behavior
Fixed Action Pattern (FAP):
A sequence of unlearned
behavioral acts that is essentially unchangeable and, once
initiated usually carried to
completion. This is triggered
by an external sensory stimulus known as a sign stimulus.
Niko Tinbergen’s
Research
Geese Imprinting
Imprinting – a type of behavior
that includes both learning
and innate components and
is generally irreversible.
• has a sensitive period
Imprinting: Konrad Lorenz with
imprinted geese
• Conservation biologists have taken
advantage of imprinting
– In programs to save the whooping crane
from extinction
Figure 51.6
•Many behaviors have a strong
genetic component.
Kinesis
Taxis
Taxis – a more or less automatic
oriented movement toward or
away from a stimulus
Ex: phototaxis in insects
towards or away from light
Ex: trout facing the current
Kinesis – an increase or decrease
in activity when stimulus intensity
increases Ex: more movement
by insects in moist soils
Migration
• Many features of migratory behavior in
birds have been found to be genetically
programmed
Figure 51.8
• Many features of migratory behavior in birds
have been found to be genetically
programmed
Environmental Cues: sun, stars, earth’s
magnetic field, landmarks
Figure 51.8
Signals and
Communication
• Nocturnal animals use
auditory and chemical
signals
• Diurnal animals use visual
and auditory signals
Signal: stimulus that causes a change in
behavior; basis of animal communication
• Pheromones – chemicals emitted by members of one
species that affect other members of the species (eg.
Queen bee, fruit fly, fish, termites, trees, humans)
• Visual signals – eg. Warning flash of white of a
mockingbird's wing
• Tactile (touch) – eg. Male fruit fly taps female fly
• Auditory signals – screech of blue jay or song of warbler
Courtship behavior of fruit flies
Staking Out Territory With Chemical Markers
Honeybee Dance
Language (von
Frisch)
• Used to
inform other
bees about
distance and
direction of
travel to food
sources
Circadian Rhythm: internal biological clock
The circadian clock in the hamster brain signals a
change in coat color according to season by
releasing the hormone melatonin.
The Suprachiasmatic nuclei (SCN) region is located
in the hypothalamus of the brain. The SCN sends
signals throughout the body in response to dark and
light.
Plants can have
two internal clocks:
one sensitive to
light and the other
sensitive to
temperature
• More on Clock Genes:
http://learn.genetics.utah.edu/content/inheritance/clockgenes/
Genetic Influences on
Mating
• Seen with prairie voles
• Male prairie voles help
to care for the young
which is unusual since
few mammals are
monogamous
•Environment, along with
genetic makeup, influences
the development of behaviors
Ex: The diet of the larvae of
Drosophila influences mate
choice later in life
EXPERIMENT
Baja males
Sonoran
males
Proportion of matings
by Sonoran females
RESULTS
100
(a)
75
(b)
50
25
0
Artificial
Organ pipe cactus
Agria cactus
Culture medium
The difference in mate selection shown by females that
developed on different diets indicates that mate choice by
females of Sonoran populations of D. mojavensis is strongly
influenced by the dietary environment in which larvae develop.
Learning
• What is the difference
between instinctive
behavior and learned
behavior?
Habituation
• Loss of responsiveness to stimuli
that convey little information
• ex: you continually drive over the
speed limit on the freeway and
never get a ticket; therefore there is
no reason to change your driving
habits.
Spatial Learning
• Cognitive Map: internal representation of
spatial relationship among objects in an
animal’s surroundings
Birds use spatial maps to relocate
nut caches
Tinbergen’s experiments on the digger wasp’s nest-locating
behavior – the wasps use landmarks to keep track of their
nests
Other ways in which
behavior is influenced:
•Associative Learning
•Classical Conditioning
Operant Conditioning
(Trial and Error Learning)
Two Kinds of Bird-Song Development: The Songs
of Most Bird Species Are at Least Partly Learned
Cognitive Ethology – young chimps
learning to crack oil palm nuts
“Fishing” by a Chimpanzee
Female warblers prefer males with
large song repertoires
•Behavioral traits can
evolve by natural selection.
Feeding by Young Bluegill Sunfish
Supporting Optimal Foraging Theory
Mating Behavior
• Promiscuous
• Monogamous
• Polygamous
–Polyandrous – single female
with several males
–Polygynous – single male with
several females
• In monogamous relationships
–One male mates with one female
(a) Since monogamous species, such as these trumpeter swans, are often
monomorphic, males and females are difficult to distinguish using external
characteristics only.
Figure 51.25a
Red – Handed Tamarin
Tamarins -the only non-human
primates that exhibit
polyandry.
Sexual Selection – a form
of natural selection in which
differences in reproductive
success among individuals
are a consequence of
differences in mating success;
proposed by Charles Darwin
Phaloropes
Peahen
Female Cardinal
Peacock
Male Cardinal
Golden Silk
Spiders
in Costa
Rica
Territoriality: Mountain Goats and
Stallions
Agonistic Behavior
• Contest that involves
threatening and submissive
behavior to gain access to a
resource (food or mate)
• What is the evolutionary
importance of agonistic
behavior?
Agnostic Behavior
Ritual Wrestling by Rattlesnakes
Inclusive Fitness
• What is altruism?
Social Behavior and Social Systems Are
Shaped by Natural Selection
• Altruistic acts— behaviors that reduce the
performer’s fitness, but increase fitness of the
individual being helped.
• An animal’s offspring contribute to its individual
fitness.
• Inclusive fitness is individual reproductive
success plus that derived from relative’s
success.
Altruistic Social Behavior
• Altruism = selfless behavior
• Reduce individual fitness but increase
fitness of others in population
– i.e. bee societies; naked mole rats
• Inclusive fitness: total effect of producing
own offspring (pass on genes) + helping
close relatives
• Kin selection: type of natural selection;
altruistic behavior enhances reproductive
success of relatives
•Leads to kin selection and
coefficient of relatedness
• Kin Selection is selection for behaviors that
increase a relative’s success, at a cost to the
performer.
• Scrub jays demonstrate helping at the nest.
• Helpers are young, prior offspring of the mating
pair
• Mating pairs with helpers have increased
reproductive success
Kin Selection and Altruism in the Belding Ground
Squirrel-Females stay closer to the burrows
Altruistic Behavior in the Belding Ground Squirrel
Vervet Monkeys Learn Correct Use of Alarm Calls