Animal Behavior - Chpt. 9 Reading Notes

Front 1

What are the four hypotheses regarding the female hyena pseudopenis and how have two of them been refuted?

Back 1

1. Extra Androgen Hypothesis: Development of the pseudopenis might be the result of exposure of the female to high levels of male sex hormones, because the male penis and the female clitoris develop from exactly the same embryonic tissues. If these tissues are exposed early on the male sex hormones, a penis is the end result. Gould thought it likely that female embryos in the spotted hyena must be exposed to unusual concentrations of male androgens. However, females administered an anti-androgenic chemical prenatally retained their elaborate pseudopenis.
4. Males could present their penis to the female and signal the suitor's male identity and thus his subordinate, nonthreatening status. Females may have come over time to respond to this signal with acceptance of the male's presence rather reacting with aggression
2.Another hypothesis is that hormones producing the pseudopenis produce other aggressive behaviors, allowing the hyenas to become more dominant. The extra-androgen-extra aggression hypothesis is at odds with the finding that adult male spotted hyenas are less aggressive than females despite having the same or higher androgen levels than females.
3.Other hypothesis is that the erect female genitalia were used to reduce tensions among the highly aggressive female members of the clan, promoting social bonds that keep the group together to work for the mutual benefit of all

Front 2

How do the sex hormones in female hyenas compare to those in males?

Back 2

FEmale spotted hyenas have circulating levels of testosterone equal to those of males; also have similar levels of a precursor of testosterone, called androstenedioine.

Front 3

What is the hyena pseudopenis used for?

Back 3

Communication

Front 4

What is the cost of the pseudopenis?

Back 4

10 to 20 percent of all females die the first time they attempt to give birth because their pups have to pass through the clitories, which is too small for this purpose

Front 5

What might be the benefits associated with a pseudopenis?

Back 5

Females with a pseudopenis have hormonal mechanisms that promote aggression; the young alpha females grow faster, are more likely to survive, and are more likely to become dominant themselves than tare the offspring of subordinate hyenas.

Front 6

Which evolved first, the female-dominant, male-subordinate relationship or the pseudopenis?

Back 6

The pseudopenis

Front 7

Why do male whistling moths produce loud ultrasonic pulses of sound by beating their knobbed wings together?

Back 7

Play a role in defense of a calling territory as well as in attracting receptive females to the caller.

Front 8

Describe the sound-receiving system in whistling moths.

Back 8

Outer ear is composed of a small ellipse of thin cuticle, called the tympanic membrane, which covers an air sac. When the membrane vibrates in response to ultrasound, the air sac also moves, supplying mechanical energy to associated sensory receptors.

Front 9

how do saturniid moths receive signals when they lack ears and cannot hear?

Back 9

Mechanoreceptor cells are attached to the saturniid thoracic cuticle, remarkably similar in structure to the mechanoreceptor cells in the ears of noctuid moths; involved modifications of existing sensory cells that peformed some other function for the earless moths

Front 10

What do the mechanoreceptors do fin saturniids?

Back 10

Translate mechanical energy from the motion of the cuticle into messages that are relayed elsewhere in the moth's nervous system, where information about the alignment of various body parts is used to adjust the moths' position in space

Front 11

Did the ancestors of whistling moths use their ears in the same ways as modern whistling moths?

Back 11

No; they almost certainly used their hearing ability for the detection of the ultrasound produced by bats.

Front 12

What are the precursors of insect wings believed to have been?

Back 12

Outgrowths of the respiratory apparatus, (the gills), of an ancestral aquatic arthropod in which the gills were attached to the legs

Front 13

What would have been an intermediate stage, between gills on arthropods and wings on insects.

Back 13

Insects with immature aquatic life stages that had respiratory gill plates on the thorax that could also be moved as an aid to underwater locomotion.

Front 14

What might have led to the first steps towards true flight?

Back 14

HInd-leg skimming; would have carried the first true fliers away from insect-eating fish into the relative safety of the air

Front 15

What changes did the advent of powered flight cause in mechanoreceptors in the thorax?

Back 15

Mechanoreceptors that once provided sensory information about the position of sailing wings relative to the thorax now could have helped their owners control their wings by monitoring wing-flapping movements.

Front 16

How did ultrasonic receptors come into existence through evolution?

Back 16

Once the ultrasonic detectors were in place, their existence affected the reproductive payoff to mutant individuals that happened to generate signals in the ultrasonic range

Front 17

What is sensory exploitation?

Back 17

When signal givers tap into preexisting perceptual mechanisms in a signal received

Front 18

Give an example of sensory exploitation in male water mites.

Back 18

Modern coutship by male water mites began when males happened to "exploit" the predator behavior of females waiting to ambush small aquatic invertebrates called copepods. While the predator female is in her attack position, called the "net stance," the male vibrates a foreleg in front of her. She, in turn, may grab him, using the same response that she uses to capture passing copepods. However, she then releases the male unharmed. He turns around the places spermatophores near the female, which she picks up in her genital opening if she is receptive.

Front 19

Why did the trembling signal in water mite courtship behavior evolve?

Back 19

Spread because it effectively activated a preexisting prey detection mechanism in females

Front 20

How do male guppies get the characteristic orange color that attracts females?

Back 20

Cannot synthesize the orange pigment, so have to acquire these chemicals, called cartenoids, from the plants they eat

Front 21

Male courtships trembling in water mites evolved at the same time as what other act?

Back 21

At the same time the predatory females adopted the net stance.

Front 22

Are female guppies attracted to orange?

Back 22

Yes, they approach and try to bite orange discs far more often than discs of any other color

Front 23

Do females respond more strongly to natural sexual attributes or artificial ones?

Back 23

Artificial ones

Front 24

Give an example of modern animals that still retain the old sensory preferences even though they no longer exhibit the complex signals themselves.

Back 24

The lizard Sceloporus virgatus lacks the large blue abdominal patches of many other members

Front 25

How do relatives of the Sceloporus virgatus lizard use their blue patches?

Back 25

Use their blue patches in the male threat posture, in which a lizard elevates and compresses its body laterally, making the abdomen visible

Front 26

If a novel test trait is is provided to a species, whose ancestors do not contain a similar trait, are they like to exhibit sensory bias?

Back 26

No

Front 27

What happened when females of a species saw males with a long yellow sword tail, (a trait that is seen relatives of the species, but evolved after the two species split)?

Back 27

The female was more attracted

Front 28

Why was the female fish more attracted to the male with the yellow sword tail?

Back 28

A female preference for long tails evolved in an ancestor before the species split and, accordingly, before a long tail ever evolved in this lineage

Front 29

Why might females respond positively to males with novel attributes?

Back 29

They could gain fitness by producing sons that could inherit the sexually attractive trait and produce many offfspring in turn; perhaps males capable of producing exaggerated courtship signals were physiologically capable of helping to rear a choosy female's offspring

Front 30

What is the "panda principle?"

Back 30

Pandas might have evolved a better thumb for bamboo shearing, but the current though is good enough

Front 31

Why might female zebra finches be predisposed to favor white feathers on their partners?

Back 31

They line their nests with white feathers

Front 32

What is an illegitimate receiver?

Back 32

An animal that uses information from the signal to the fitness detriment of the legitimate signaler and receivers

Front 33

Give an example of an illegitimate receiver.

Back 33

Raccoons listen in on the communication taking place between a brood of baby tree swallows and their parents

Front 34

Describe the "seet call" of a great tit.

Back 34

If a great tit spots a flying hawk, it gives a much quieter "seet alarm call than the mobbing calls of European songbirds; enough to warn mates and offspring of possible danger, but lowers the chance that a dangerous predator on the hunt will be able to tell where the caller is. Predation pressure by bird-eating hawks has favored the evolution of alarm calls that are hard for hawks to hear.

Front 35

When a male toad find another male mounted on a female, he may try to pull him back from her. Why does the newcomer often back away?

Back 35

The mounted male croaks as soon as he is touhced, and often the other male immediately concedes defeat and goes away, because the pitch of the crock can indicate the toads size. Deep croak do deter rivals to some extent, although tactile cues also play a role in determining the frequency and persistence of an attack. (Toads have evolved a warning signal that accurately announces their body size.)

Front 36

How does natural selection deter mimicry?

Back 36

As mimics became more commmon in the population, natural selection would favor receivers that ignored the easily faked signals, reducing the value of producing them. This, in turn, favors the spread of the genetic basis for an honest signal that could not be devalued by deceitful signalers.

Front 37

What are illegitimate signalers?

Back 37

Use deception to reduce the fitness of a receiver.

Front 38

Give an example of an illegitimate signaler.

Back 38

The "femme fatale" firefly

Front 39

How does the "femme fatale" firefly attract its prey?

Back 39

Each species of Phontinus has its own code, with a female answering her male's distinctive flash pattern by giving a flash of her own after a precise time interval. Some females can respond to the signals of three other species. If the female succeeds in luring a male close enough, she will grab, kill, and eat him