Lecture 4

Question 1

what is sexual mimicry

Answer 1

where the sexx of one species resembles the other sex
mostly mimicry of primary seual charac by females

Question 2

which hyena is the one that displays sexual mimicry

Answer 2

spotted hyena
only this one is obligate carnivore, apex predator

Question 3

diff between female and male phallus/pseudophallas

Answer 3

females is shorter, stubbier
males longer and thinner
female has a false scrotum caused by fusion of labia
females is heavily pleated on inside, full of loose connective tissue (to facilitate birth)

Question 4

whats the female thingy called

Answer 4

peniform clitoris

Question 5

what opening does female have

Answer 5

urogenital sinus that extends throught the length of the peniform clitoris - no vaginal opening

Question 6

what 3 things is peniform clitoris used for

Answer 6

amicturation
copulation
parturition

Question 7

hyena mating

Answer 7

very hard
male = semi-erect, female = flaccid
female uses retractor muscles to assist
cooperative effort

Question 8

where are female retractor muscles located

Answer 8

dorsal
unlike males which is ventral

Question 9

what par tof clitoris ruptures during birth

Answer 9

vetral part (hence why retractor muscles have to be dorsal
or they would be damaged and cant reproduce any more)

Question 10

normal hyena pup size

Answer 10

• large pups (1.1-1.6kg)

Question 11

dystocia

Answer 11

• dystocia = long, hard parturtion

Question 12

who is birth harder for

Answer 12

• harder for primiparous (first time mums)

Question 13

cervical length of hyenas

Answer 13

• cervix distance is double length of normal mammals this size (60cm)

Question 14

length of umbilicus

Answer 14

12-18cm
w the long cervical length, it has to break before birth

Question 15

2 complucations of birth that can occur

Answer 15

pup can lodge in peniform clitoris
precocious (early) `neoplacental detachment

Question 16

neonatal mortality rate

Answer 16

60% in captivity

Question 17

death rate of primiparous mums

Answer 17

9-18%

Question 18

% reduction in biological fitness as consequence of birth situation

Answer 18

25%

Question 19

what is social domination theroy for sexual mimicry

Answer 19

sniff each others winkles as social greeting
- females reinforce their position in society by developicng delicate winkles, as lots of trust required in this act as hyenas have shapr teeth

idk doesnt make sense to me

• also to avoid infanticide by the males, since females can camoflague and appear more dominant
• avoid aggression from other higher ranked ranked

Question 20

hyenas not polygamous, they are?

Answer 20

polyandrous
where female has multiple men (polygamy is men have multiple females)

Question 21

whats diff with male mating tactic in polyandrous compared to polygamy

Answer 21

all males get a chance at hitting it
not just the alphas or the ones that beat the other males

Question 22

sperm fitness and selection theory for sexual mimicry

Answer 22

long and complex genitourinary sinus promotes internal sperm selection (cuz lack of selection externaly)

Question 23

issue with sperm fitness and selection theory for sexual mimicry

Answer 23

hyena testes are small
unlike most polyandrous species (becuase in polyandry, bigger is better otherwise dont have much going for you)

also
oestrus cycle of female doesnt have the same synchronisation as other species that have active sperm selection

Question 24

what does competition aggression hypothesis require for it to be true

Answer 24

• lots of competition for food, selects for bigger, more aggressive females
• requires that the female rank, body size and aggression is linked to reporductive success
  and also variance in reproductive success is greater in females than males
  (unlike polygynous)

Question 25

why is competition aggression hypothesis mroe likely to be true

Answer 25

females are larger, more aggressive than males, masulanised behaviours female status is key predictor of offspring survival so masculanised genitalia may be a by-product of these behavioural adaptations also hyena pups wean for 6 months, and the milk has highest protein content of other carnivores so she spends a lot of energy in gestation and cub rearing therefore her beh and size gives her priority access to food/resources, which is essentia to meet these demands

Question 26

what enzyme do hyenas have that converts androstenedione to testosterone

Answer 26

17Beta hydroxysteroid dehydrogenase high levels compared to other mammals

Question 27

what neonatal andogen blocker was used in experiment

Answer 27

cyprotreone acetate only a partial androgen blocker so not v accurate

Question 28

result of androgen blocker action

Answer 28

impedes phallic masculinisation in both males and female but in males it also promotes feminisation (shorter and thicker winkle) revereses high neonatal mortality males unable ot mate,

Question 29

sexual dimorphism in hyena

Answer 29

different mounting behaviour male sexually dimorphic nucleus (SDN) in hypothalamus larger than females cell numbers hugher but not as much as most other mammals hence chimeric bheaviour

Question 29

correlation of social rank with androgen level

Answer 29

faecal steroidconc measured more dominant females produce higher levels of androgens in pregnancy

Question 30

effect of high uterine androgen levels in cubs

Answer 30

more aggressive, male beh therefore more dom female = more androgens in pregnancy = more aggressive pups so dom is inherited

Question 31

elephant sexual mimicry

Answer 31

male = no scrotum(intraabdominal testes), female has hypertrophied clitoris that resembles a winkle not as pronounced as hyena mimicry also mating requires cooperation too matriarchal social structure

Question 32

sexual mimicry in moles

Answer 32

testis are inraabdominal hard to differentiate m and f females have ovotestes which are seaonally dynamic (in spring, normal ovarian tissue appears, autumn turns more testicular) wtaf test up for males in breeding season, in females it goes down and vice versa in non breeding season