agonistic.html: 51_30AgonisticBehavior.jpg
Agonistic behavior.
These two male polar bears (Ursus maritimus) are engaging in “play–fighting,” ritualized contests that usually do not injure the bears.
By contrast, during the spring breeding season, male polar bears fight fiercely as they compete for access to females in estrus.
Chimpanzees Wolves Snakes Elephant seals
altruism.html: 51_35SquirrelKinSelect.jpg
Kin selection and altruism in Belding’s ground squirrel.
After they are weaned, females are more likely than males to live near close relations.
Alarm calls that warn these relatives increase the inclusive fitness of the female altruist.
If all of a female's close relatives are dead, she rarely gives alarm calls.
cichlid.html: 51_02MaleAfricanCichlid.jpg
A male African cichlid (Neolamprologus tetracephalus) with erect fins.
Muscular contraction that raises the fins is a behavioral response to a threat to the fish's territory.
cjohnsoni.html: 51_10BirdSongGenetic_Cjohnsoni.jpg
_BED_/sketches/sounds/Arthropoda/Chrysoperla_johnsoni.wav
classical_conditioning.html: Classical_conditioning.gif
Classical conditioning was demonstrated by Ivan Pavlov with dogs.
An unconditioned stimulus (UCS) normally elecits a specific, unconditioned response (UCR).
If the UCS is associated with a neutral stimulus (NS), the latter may become a conditioned stimulus (CS) and elicit the same response, now called a conditioned response (CR), in the absence of the UCS.
Advertisers often rely on classical conditioning to associate their products with a desirable
stimulus.
cplorabunda.html: 51_10BirdSongGenetic_Cplorabunda.jpg
_BED_/sketches/sounds/Arthropoda/Chrysoperla_plorabunda.wav
crane.html: 51_06ImprintUltralight.jpg
Imprinting for conservation.
Conservation biologists have taken advantage of imprinting by young whooping cranes
as a means to teach the birds a migration route.
A pilot wearing a crane suit in an ultralight plane acts as a surrogate parent.
cranes.html: 51_01BirdCourtship.jpg
A courting pair of East Asian red-crowned cranes
(Grus japonicus).
digger_wasp.html: 51_14DiggerWaspLandmarks.jpg
EXPERIMENT
A female digger wasp excavates and cares for four or five separate underground nests,
flying to each nest with food for the single larva in the nest.
To test his hypothesis that the wasp uses visual landmarks to locate the nests,
Niko Tinbergen marked one nest with a ring of pinecones.
After the mother visited the nest and flew away, Tinbergen moved the pinecones a few feet to one side of the nest.
RESULTS When the wasp returned, she flew to the center of the pinecone circle instead of to the nearby nest. Repeating the experiment with many wasps, Tinbergen obtained the same results.
CONCLUSION The experiment supported the hypothesis that digger wasps use landmarks to keep track of their nests.
Tinbergen received the 1973 Nobel prize in Medicine with Karl Von Frisch and Konrad Lorenz.
drosophila.html: 51_12DrosophDietMateChoi.jpg
EXPERIMENT
D. mojavensis populations from Baja California and Sonora were raised on three different culture media:
artificial medium, agria cactus (the Baja host plant), and organ pipe cactus (the Sonoran host plant).
From each culture medium, Etges collected 15 male and female Baja D. mojavensis pairs and 15 Sonoran pairs and observed the numbers of matings
between males and females from the two populations.
RESULTS When D. mojavensis had been raised on artificial medium, females from the Sonoran population showed a strong preference for Sonoran males (a). When D. mojavensis had been raised on cactus medium, the Sonoran females mated with Baja and Sonoran males in approximately equal frequency (b).
CONCLUSION
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.
drosophila_mate-choice.html: _FPX_18
51_12DrosophDietMateChoi.jpg
The physiological basis for the observed mate preferences in D. mojavensis
was differences in hydrocarbons in the exoskeletons of the flies.
fap-imprinting.html: _FPX_18
51_05GraylagImprinting.jpg
Proximate and ultimate perspectives on imprinting in graylag geese.
BEHAVIOR: Young geese follow and imprint on their mother.
PROXIMATE CAUSE: During an early, critical developmental stage, the young geese observe their mother moving away from them and calling.
ULTIMATE CAUSE: On average,
geese that follow and imprint on their mother receive more care and learn necessary skills,
and thus have a greater chance of surviving than those that do not follow their mother.
fap.html: 51_04FishAggressiveBehav.jpg
Proximate and ultimate causes for male stickleback aggressive behavior.
BEHAVIOR: A male stickleback fish attacks other male sticklebacks that invade its nesting territory.
PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus that releases a fixed action pattern (FAP) - aggression in a male stickleback.
ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreases
the chance that eggs laid in his nesting territory will be fertilized by another male.
imprinting.html: 51_05xGeeseImprinting.jpg
Konrad Lorenz
showed that when baby geese spent the first few hours of life (the sensitive, or critical, period)
with him, they imprinted on him as their parent.
Conservation biologists have taken advantage of imprinting in programs to save the whooping crane from extinction.
Another example is the restocking of Sockeye-salmon
in streams depleted of wild populations.
kinesis.html: 51_07Kinesis.jpg
Kinesis involves a simple change in activity or turning rate which
increases the chance that a sow bug will encounter and stay in a moist environment.
lacewing.html: 51_10SongGenetic.jpg
EXPERIMENT
Chrysoperla plorabunda and Chrysoperla johnsoni are
two morphologically identical species of lacewings that sing different courtship songs.
RESULTS The F1 hybrid offspring sing a song in which the length of the standard repeating unit is similar to that sung by the C. plorabunda parent, but the volley period, (the interval between vibration volleys), is more similar to that of the C. johnsoni parent.
CONCLUSION
The results of this experiment indicate that the songs sung by
C. plorabunda
and
C. johnsoni
are under genetic control.
mating-monogamy.html: 51_25MatingSystPhenotypeA.jpg
Since monogamous species, such as trumpeter swans, are often monomorphic,
males and females are difficult to distinguish externally.
polygyny
mating-polyandry.html: _bed_/sketches/sounds/Chordata/Aves/Wilsons_Phalarope.mp3
/sketches/sounds/Chordata/Aves/IMG/Phalaropus_tricolor.jpg
In polyandrous species, such as Wilson’s phalaropes where incubation and chick rearing are done by males,
females (top) are generally more ornamented than males.
mating-polygyny.html: 51_25MatingSystPhenotypeB.jpg
Among polygynousspecies, such as elk, the male (left) is often highly ornamented.
polyandry
microtus.html: 51_11HuddlingVoles.jpg
A pair of prairie voles (Microtus ochrogaster) huddling.
North American prairie voles are monogamous, with males associating closely with their mates, as shown here,
and contributing substantially to the care of young.
migration-genetics.html: 51_21MigrationGenetics.jpg
Blackcaps placed in a funnel cage left marks indicating the direction in which they were trying to migrate.
Young birds from Germany were oriented toward the
southwest, their traditional wintering grounds in the Mediterranean.
Recently, some blackcaps from continental Europe started wintering in Britain;
these birds had a migratory orientation toward the west (Britain),
indicating different genetic migratory instincts between the 2 populations.
migration.html: 51_08BirdMigration.jpg
Each spring, western sandpipers (Calidris mauri) migrate from their wintering grounds,
as far south as Peru, to their breeding grounds in Alaska.
In the autumn, they return to the wintering grounds.
minnow.html: 51_09MinnowAlarmResponse.jpg
| When a minnow is injured, it releases an alarm substance, inducing a fright response among fish in the area. | ||
| Minnows are widely dispersed in an aquarium before an alarm substance is introduced. | Within seconds of the alarm substance being introduced, minnows aggregate near the bottom of the aquarium and reduce their movement. | |
molerat.html: 51_33NakedMoleRatAltruis.jpg
Naked mole rats, colonial mammals that exhibits altruistic (selfless) behavior.
Each colony has only one reproducing female, the queen, who mates with one to three males, called kings.
The rest of the colony consists of nonreproductive females and males who forage for underground roots and tubers and care
for the queen, the kings, and new offspring still dependent on the queen.
operant_conditioning.html: 51_16Coyote_Porcupine-OperantConditioning.jpg
Operant conditioning.
Having received a face full of quills, a young coyote has probably learned to avoid porcupines.
relatedness.html: 51_34CoeffRelatedness.jpg
The coefficient of relatedness between siblings.
The red band indicates an allele on a chromosome of a homologous chromosome pair in one parent.
Sibling 1 has inherited the allele from parent A. There is a probability of 1/2 that sibling 2 will also inherit this allele from parent A.
The coefficient of relatedness between the two siblings is thus 1/2, or 0.5.
sign.html: 51_03SignStimulusA.jpg
A male three-spined stickleback fish shows its red underside, which serves as a sign stimulus
to other male sticklebacks
.
signal.html: 51_03SignStimulusB.jpg
Sign stimuli in a classic fixed action pattern.
The realistic model at the top, without a red underside, produces no aggressive response in a male three-spined stickleback fish.
The other models, with red undersides, produce strong responses
.
stalk-eyed_flies.html: 51_29MaleStalkEyedFlies.jpg
Female stalk–eyed flies prefer males with long eye stalks.
taxis.html: 51_07Taxis.jpg
Positive rheotaxis keeps trout facing into the current,
the direction from which most food comes.
This also helps the fish from being swept downstream.
zebrafinch-imprint.html: 51_28SexSelectImprinting.jpg
Sexual selection influenced by imprinting.
Experiments demonstrated that female zebra finch chicks that had imprinted on artificially ornamented
fathers preferred ornamented males as adults.
zebrafinch.html: 51_27SexualDimorphism.jpg
Zebra finches, native to Australia.
Male zebra finches are more ornate
than females, a trait that may affect mate choice by the females.
zebrafish.html: 51_15AssociativeLearning.jpg
Associative learning in zebrafish.
Changes in activity indicated that the experimental group of zebrafish had learned to associate the odor of pike with the presence of alarm substance.