Recaps of class meetings, Phase 3:

10/30/96: Maternal behavior of the lab rat Rattus norvegicus

SIRE / DAM / PUPS

Despite an early failure by Calvin Stone to demonstrate the influence of blood-borne substance on the development of maternal behavior, Terkel was later able to transfer maternal behavior from a new mother rat to a virgin rat, using exchange of blood via a small pump. Later examinations of Stone's parabiosis procedure concluded that it should have worked, but must have been blocked by an unseen blood clot during the operation to connect the blood vessels of the two rats.

Even though it now seems clear that something in the blood does influence the display of maternal behavior, we do not as yet have a 'recipe' of exactly what hormones to inject to accomplish this. But researchers are getting close to a solution of the puzzle.

The 22-day gestation period of the rat can be divided into 3, one-week, trimesters. In trimester 1, almost nothing changes in the female's behavior. During trimester 2, she becomes a bit less active, and starts gaining weight. During trimester 3, she becomes more lethargic, develops her mammary tissue, gains weight and, about day 19-21 builds a nest IF she has something to build with, and the room is not too hot.

Just prior to parturition, she can be seen stretching out her hind legs, and full body. For delivery of the first pup, she sits on her haunches, bends forward between her hind legs, and licks her vaginal area. As the pup emerges, she assists the birth by pulling with her paws and teeth. After it is born, she stretches the umbliical cord between the placenta and pup, and either breaks it or bites it loose, then eats the placenta. She strips the pup of its fetal membranes, and licks it. She usually leaves it wherever it was born, and proceeds to deliver # 2, then 3-10 or so. Then she begins retrieving them one by one to her nest, with a full body carry, without cutting them with her teeth.

When she has all in the nest, she goes into a nursing crouch -- spread-eagled over them, so they can find a nipple, and suckle. The pups are very altricial, but can find a nipple, attach, and eat. She spends quite a bit of time in the nest with them, keeping them warm, as they cannot control their own temperature.

For the first week or so the mother must lick the pups abdomen and anal and urinary areas, to simulate defecation and urination; else the pups will impact and die.

During week 2, the pups' eyes open, their fur becomes evident, and they start to move around. As they leave the nest, the mother retrieves them back. She very gradually gives up on retrieving them back, when they become too active for her to succeed in keeping them in the nest.

During weeks 3 and 4, the pups gradually gain the ability to run and climb, and to eat solid food. Sometime during week 3 or 4 the mother weans them, by refusing them access to her nipples. This may or may not be her reaction to their developing teeth.

This species has extremely altricial young. They appear underdeveloped when born, and have very few capabilities. The mother furnishes heavy support for them - else they would die. In the lab rat, the sire is not much help, and may even be a danger to the pups. The mother will defend her nest against strangers and, sometimes, against the sire.

11/1/96: Maternal Behavior of the rat (cont'd) and comparisons with the lab mouseMus domesticus: SIRE / DAM / PUPS

In the late 30's and early 40's Oscar Riddle and colleagues published a number of studies reporting that prolactin was "the" maternal hormone, based on their results with the lab rat. This assertion was then picked up by a number of Psych textbooks. -But it ain't so simple! A number of people, including me, have tried to replicate this work, but could not. It seems likely that prolactin may have something to do with the display of maternal behavior, but simple injections of prolactin to a virgin rat will not do it.

In the 30's also, Wiesner and Sheard published a book entitled "The Maternal Behavior of the Laboratory Rat." Their descriptions are still accurate and useful. They describe a technique of inducing maternal behavior in the rat, a technique they gave the odd name of concaveation. Basically it consists of placing 1-3 day-old rat pups overnight with a test animal, and then returning the pups to their mother in the morning, so they can eat. For most rats, 7 days of concaveation will bring them into maternal state. Males sometimes take a little longer. Virgin females can also be induced to begin lacation with this technique. There have been reports of induction of lactation in males, too.

The main use of concaveation now is to measure the 'maternal tendency' of a rat, since without concaveation, the measurement is either Yes or No, for retrieving of pups. Using concaveation, a researcher can try a hormone injection regimen, and then see if the 7-day concaveation period has been reduced or not. Currently, there are hormone regimens that can reduce the concaveation requirement to 1 or 2 days, but none to my knowledge that can reduce concaveation to 0 (i.e., immediate retrieving).

Rosenblatt, Bridges, and colleagues have also determined that Caesarian section of pregnant rats will hasten the onset of maternal behaviors, as measured by the reduction in concaveation requirements. After about day 10 of pregnancy, the removal of the pups by c-section will reduce the concaveation requirement to display MB. This reduction has been termed the PREGNANCY TERMINATION EFFECT. It may be due to the release of pressure, or to the removal of placental hormones, or even to the stress of the operation.

The lab mouse MB is very similar to that of the rat, though their gestation period is about 1 day shorter (21 days). In the lab mouse, however, the male (father, usually) is useful in that he will sit in the nest and keep the pups warm. He of course cannot feed them milk (male mice do not have even vestigial nipples). Most of the research on MB has used either the rat or the mouse. This may have been a mistake, as these species are not really very typical of mammals in that they both have a very short estrus cycle, skipping the luteal phase unless mating has occurred. But we will see. If someone can devise a hormone injection regimen that can key off MB in a fairly short time, that regimen or a similar one may be found to influence MB in other mammals, including people.

11/4/96 - Maternal Behavior of the domesticated rabbit Oryctolagus cuniculus: BUCK / DOE / KITS

Student Lecturers: Kelsey Hartman & Mike Clapp

The doe rabbit's puberty is at about 8 months, although rabbit breeders advise not breeding her until 1 year. Her estrus cycle is hard to discern, as she is an induced ovulator -- she does not ovulate until after sexual excitement such as breeding by a buck rabbit, or being mounted by another female. This excitement results in a surge of FSH which matures the ova in about 10 hours, and then she ovulates, presumably after a surge of LH.

Her gestation period is about 30-32 days. There is little change during the 1st trimester; some weight gain in the 2d, more weight gain in the 3rd, along with nest-building near term at about day 29-32. She will build a nest in a burrow with grass and twigs, and then line it with her body hair. For about a day, near term, her belly hair loosens. She then pulls it out with her teeth, and lines her nest with it. The doe usually has her kits IN the nest. If she 'scatters' them, or eats them, this is a sign of bad maternal behavior. "Scattered' kits usually do not survive, as the mother does NOT retrieve.

The doe typically nurses her kits only once per day. This may be to minimize the danger of predators finding her and them. The kits are altricial (blind, etc.), but not quite so altricial as rat and mouse pups. Their eyes open at about 2 weeks. The doe may nurse them for 4-10 weeks. During most of her lactation period she is very protective of the nest and kits, and will threaten and bite intruders.

If the doe is sexually excited by a female mount or that of a vasectomized buck, she will usually go into pseudopregnancy for 30 days or so -- about the same time that real pregnancy would have lasted. The doe often has a post-partum estrus, and may breed again if the buck is present. However, is she is nursing litter 1, she will usually resorb litter 2 at about day 10 of their development. If she loses litter 1 however, and is not nursing, she will probably carry litter 2 to term.

Rabbits are in extensive use in research. Despite many tries we do not as yet have a 'recipe' of hormone injections that will reliably elicit maternal behavior. However, sequential injections of estrogen, progesterone, then prolactin (mimicking levels during normal pregnancy) will bring most does into lactation; it sometimes succeeds in causing bucks to lactate, as well. Rabbits are often used to produce antibodies for research and for medical use, as they are large and produce good quantities.

Since rabbits do not retrieve, this cannot be used as an index of their maternal behavior. Instead, the typical response used is the presence or absence of a hair-lined nest. When a doe lines her nest with hair, this is a good indicator that she is in maternal condition, and will take good care of kits (nursing; little cannibalization; little scattering).

11/6/96: Maternal behavior in the domesticated sheep, Ovis aries: RAM / EWE / LAMBS

Student Lecturers: Laura Hodgkins & Autumn van Kirk

The ewe undergoes puberty at about 9 months, although sheep herders usually prefer to delay breeding until she is 12 months or more. She has a 16-17 day estrus cycle, and is said to be 'seasonally polyestrous' in that her cycles occur in September through December. The ram is also somewhat seasonal in his sexual interests.

Toward the end of gestation, the ewe tends to separate from the flock somewhat, and find a secluded place for the birth. In domestic sheep, 'lambing sheds' are often provided so that the ese can be alone with her lamb when it is born. Just before parturition the ewe is seen to be restless, and sometimes grunts often. She lies down for the birth which takes about 30 min. She may have 1, 2, or 3 lambs --this is somewhat dependent upon the race or breed of sheep.

After the birth she eats the placenta and licks the lamb dry. This period is very important for formation of the mother-infant bond. If licking of the lamb is denied the mother, she may not want the lamb when it is offered to her later. The lamb is precocious, and soon stands and finds its mother's udder for its first meal. If the lamb is removed from the mother for more than a few hours, she may not accept it back. If she has had several hours alone with the lamb, just after birth, the bond seems stronger, and able to withstand longer absences.

The ewe-lamb pair or group stay in close proximity for several months, although they gradually rejoin the herd. The lamb usually follows it mother, nursing from time to time. However, the lamb will try to suckle from other ewes, who recognize that it is not theirs, and butt it away.

It is sometimes necessary or desired to have a ewe adopt a lamb that it not her own. Many strategies have been devised to help this process, such as draping the adoptee with fetal membranes, etc. None was very successful. Poindron and colleagues, however, discovered that vaginal stimulation of the ewe prior to introduction of the adoptee lamb would result in adoption by the ewe most of the time. The vaginal vibrator causes a release of oxytocin, which must facilitate the adoption.

Lambs can graze within a few weeks of birth, and are usually weaned between 3 and 6 months.

Maternal behavior in the Wyoming elk, Cervus elaphus canadensis: BUCK / DOE / FAWN, or STAG / COW / CALF

Student Lecturers: Erin Zumwalt, Kaisa McDonnall & Hillary Boudeman

After puberty at 2 or 3 years, the doe elk breeds and has an 8 1/2 month gestation period. Prior to parturition, she drives away her yearling fawn by threats and butts. She delivers the fawn while standing, and then turns, eats the placenta and licks the fawn so it will stand. When it stands, she positions herself so it has easy access to her udder, for its first, cirtical meal. If it cannot stand and reach the udder, it will probably die.

After its meal, the doe pushes it down with her head, to hide it in the bushes. The fawn has very little odor, and remains very still to avoid drawing the attention of predators. The doe then rejoins the herd to graze. She returns from time to time to check on the fawn and to feed. it. Sometimes elk mothers will 'play nurse' and check on each others fawns. The doe returns to the fawn in the evening, and spends the night with it or them.

After the first few days, the doe begins to integrate the fawn into the herd, where it soon begins to play rush and flight, and water games with other youngsters. The fawns also practice mounting each other. During this phase they seem to learn some of the communication signals in the herd, such as the meaning of the 'high step' warning gait, and the freezing posture. Sometimes the doe (cow) will join or initiate games with the fawn (calf).

When the herd migrates it must cross streams and rivers. The early initiation to water seems to help the fawn avoid fear of these crossings. During crossings, the mother places the offspring upstream from her, so she can help hold it from being washed away by strong currents, as they swim across.

The mother-infant bond may seem to be broken when the mother chases away her yearling just before the next breeding season. But, cows have been know to 're-adopt' their yearling (who is nearly as big as the mother), and let it nurse again, after the breeding season. Also, there are indications that the pair remain somwhat bonded for much of their life.

11/8/96: Parental behaviors in the baboon, Papio papio: MALE / FEMALE / INFANT

Student lecturers: Dan Berkey & Jill Ridley

Baboons go through puberty at about 3 years, although the males must wait for several more years before they are large enough to achieve enough dominance status to mate. The female's gestation period is about 6 months. She usually delivers at night, when the troop is stationary, in the trees. However, a few day deliveries have been observed; she assumes a squatting position, and helps the delivery by pulling on the infant with her hands. She then cuts the umbilical cord, eats the placenta, cleans the infant, and puts it to breast. The infant remains in almost constant body contact with its mother for a period of months.

The infant is altricial, but its eyes are open, and it can grip onto its mothers ventrum and hang on as she walks. If the troop moves for a long period, the infant may tire, and drop its hind legs. If the mother can do so and not lose contact with the troop, she will stop and hold the infant in her arms a while to let it rest. If she must keep moving, she will sweep the infant back to her ventrum with one arm, and may even help hold it there is it is necessary.

A mother with a new infant effectively goes to the top of the heap in rank, and stays in the center, most protected area of the troop. The troop members are extremely interested in the infant, and try to get the mother to let them hold it. She usually refuses, except to dominant males. If a dominant male takes the infant he usually examines it closely, and then gives it back without harm. But this is a traumatic interaction for the mother. Low ranking females sometimes give up their infants briefly to other, higher ranking females.

The mother keeps the infant in her arms as she sleeps in a tree. During the course of the first few months the year-olds try to entice the infant away from its mother, to play. The infant very tentatively will try this, and then run back to its mother. The year-olds are very gentle with it, but if it cries the mother immediately intervenes. A bit later, when the infant is actually playing with the year-olds, a cry from it will quickly bring intervention from the nearest adult male, too.

After about 3 months, the infant will try to ride on its mother's back. At first it lies spread-eagled, crosswise. Then it lines up, but still rides spread-eagled, face down. Gradually as it gains strength and balance, it will sit up, jockey position. When it is able to ride, this makes things much easier for its mother, as while it is hanging beneath it makes walking and running much harder for her.

The infant may nurse for 10-12 months before the mother weans it. It has been eating some solid food long before it is weaned. As it gets older, it likes to play on the adult males, who are extremely tolerant of it, letting it climb and sit on their head, poke at eyes, pull fur, etc. The males seldom seem to discipline it, although the mother sometimes will give it a push, mock bite, or hold it down, for discipline.

During her lactational period, the female skips estrus/menstrual cycles. The hormone balance necessary for constant lactation seem to exert an effect on her pituitary to delay cyles until after lactation is over. However, is she loses the infant, her milk will dry up, and she will begin cycling again.



Parental behavior in humans, Homo sapiens sapiensMALE / FEMALE / INFANT, or FATHER / MOTHER / BABY

Puberty in humans occurs around 11-14 in females, and around 12-15 for males. Gestation averages about 10 lunar months, i.e., 280 days. The human infant is also altricial, more so than the baboon, but less so than the rat or mouse. It takes about 6 months for the human baby to get to the developmental stage seen in newborn baboons, and the baboon infant matures much faster than does the human.

Infant care is relegated largely to females --usually the mother -- in most societies. Time-sampling of parental care in a western society concluded that the father cares for the infant less then 30 minutes a day on average, leaving the rest of the 24 hours to the mother.

Though cognitive development in humans is such that essentially any person can care for an infant fairly well, it does seem to me likely that humans also get some impetus from hormones to increase maternal responsiveness. A new mother is extremely interested in her baby, very protective, etc. Men on average are interested, but usually not as intently as the mother. And, we can look at this issue in another way: When a new mother is so atypical as to throw her baby in the dumpster or toilet, most of us are shocked at this huge departure from usual maternal behavior. A complication of course, is our cognitive development, with some new mothers understanding that they cannot support the baby, or even deal with it in their social (perhaps teenage, unmarried) situation. So it is hard to be sure whether there has been a failure of maternal hormones when the baby is killed or thrown out. or whether social pressures have overwhelmed what would have been a natural maternal tendency in the mother.

Interestingly, as shown by R.V. Short, in societies where mothers nurse their babies night and day for 3 years or so, they also show lactational amenorrhea, i.e., no menstrual cycles until after weaning. This seems to be a natural way of spacing births. In most western societies the intensity of nursing is not sufficient to stop cycles, and pregnancy can occur again during her nursing period. Short also discuss many of the advantages of breast feeding, including transfer of needed antibodies, less diarrhea (a principal cause of infant mortality), convenience, low cost, and mother-infant bonding. As we know, many in western society see disadvantages, including great inconvenience for working mothers, and cosmetic changes such as breast-shape. And many mothers combine breast and bottle feeding.

As we know, the development of human children is a long process, with sitting up and crawling about 6 months, walking at about 12 months, toilet control by 24 months usually, but brain and intelligence growth until about 16 years of age. And even then, our children are not considered fully mature (driver's license - 16; voting 18 (previously 21); legal adult at 21, etc. And many of us after 21 are still 'training' i.e., in school, etc. The parent-child bond seems to lessen somewhat as the teenage years go by, but in most cases never really ceases.

GENERAL: One clear lesson that we can draw from our cross-species survey of maternal behaviors is that species have evolved in such a way that the very different demands of offspring in different species are met adequately by a parent -often the mother- and, as the offspring matures and acquires more capabilities, the support given by its parent lessens, until after maturity the offspring functions independently.

11/11/96: Introduction to agonistic behaviors

Student lecturers: Jeanne Huestis & Kari Mau

We use the term agonistic, so we can include both aggressive behaviors, and responses such as submissive behaviors and other behaviors that we and other species use to respond to aggression.

Ken Moyers has several times listed categories of aggression, as he sees it. Of course, his list changes a bit from time to time. Here is one of the Moyer lists:

1. Predatory aggression - (Does this seem like a type of aggression?)

2. Inter-male aggression - In most species, most overt aggression is by males.

3. Terror-induced (or fear-induced) - As in "A cornered rat will fight"

4. Irritable - As in rat foot-shock experiments, to stimulate fighting

5. Territorial defense - In many species. both male and female show this

6. Defense of young (maternal aggression) - usually by the female

7. Instrumental - usually a learned aggression, as in lab reinforcement for attacking/fighting

Of course, other categorizations are possbile. But we will work with the Moyer categories, at least at first, and try to find hormonal correlates for each type

There are many possible response to aggression besides fighting back. Fleeing or at least leaving is a common response. There are also a number of submissive postures or gestures that are somewhat species-specific. In humans, e.g., we have many submission gestures, such as (in order of amount), bowing the head, bowing from the waist, kneeling (as before a monarch, or in prayer), kneeling with head to ground, prostration (again as before some monarchs, or perhaps a monk in prayer). Kissing can also signal a degree of submission, e.g. kissing cheek (essentially equals), kissing hand (some submission, as gentleman to lady), kissing knee (deep submission), kissing foot or ground near foot (abject submission). Hand-shaking is also a signal -- originally that intentions were friendly, i.e., no weapon in hand. It essentially signifies equality. It is used very differently in different cultures, for example it is rare in France between man and woman, who would prob. kiss cheeks instead. Saluting, as in military is a direct signal of submission: the lower ranking person offers an immediate hand salute to a higher ranking person of any military service, including those of allied countries. The higher ranking then acknowledges their relative status, by returning the salute.

Also involved in some of the social interchanges that may include some threat or aggression are the distances that we maintain from others (These differ, by culture -- further in US, Australia and N. Europe; closer in Mediterranean countries). It is not uncommon that a breach of 'individual distance' - that is, someone comes closer to us than our 'individual distance' requires, we feel quite uncomfortable, and may even see this close approach as threatening or aggressive. In western societies, average individual distances are something like 2 1/2 to 4 ft. -- just out of arms reach! This probably tells us that we are not expecting to be touched, and that touching will probably be resented. Yes, we know some strong counter-examples, Pres. Clinton, for example. Interestingly, it is usually considered that the person who offers a shoulder embrace or some such touch is being dominant, and the receiver is put in a subordinate position. But there are certainly exceptions. For example, it is usual to offer small back-pats of encouragement to someone who has been hurt, while you are waiting for help.

Cultures that have a very small individual distance sometimes say that friends should be close enough in a conversation that they can smell each other. And anything further is considered cold-fish. Naturally, US, Australian, N. European people are sometimes considered cold by Mediterranean peoples, when the US person keeps backing off to 3-4 ft., as the other keeps trying to get within decent conversational distance - say 1 ft.!

Notice the trouble we are still having with hand-shaking: Originally, the subordinate offered his hand, to prove it was empty of weapons. Gradually, the offer came to be made almost simultaneously, but it is still awkward. Most men watch carefully for a small sign of an upcoming handshake, and then rapidly respond so it seems simultaneous (to show equality). This is compounded by handshakes between men and women. Originally, the woman offered her hand to be kissed. A gentleman responded by kissing the hand (showing mild subordination as a courtesy). Now that offering a hand for kissing is rare, who should offer a hand for shaking first? Most books on etiquette say for a man to wait for a woman to offer her hand, not to put his hand out first. But, his waiting tends to signal some dominance-intent, and is thus mildly confusing in many social situations. Many French people consider that for a man to shake hands with a young girl he has just met is a signal that they have some 'understanding'. Since it would be improper for them to have an 'understanding' when they have barely met, handshaking between sexes should be avoided.

11/13/96: Agonistic behaivors(Cont'd) + rats and mice

** An 'Old Exam 3' has been placed in Norlin Reserve **

Agonistic Behavior, Cont'd:

All individuals need some assertiveness or aggressiveness, to obtain what they need.

However, individuals in groups need a balance: too much aggression and they will be driven off, and will probably die; too little, and they will not obtain what they need.

The needed balance is what Ardrey calls the 'Social Contract'.

Some more types of aggression:

** verbal

** isolation-induced

** passive

** displaced

** frustration-induced

Rats/Mice

** Mostly males

** Mostly post-pubertal

** Mostly for dominance

** Mostly androgen-based (Cf. castration)

** First to attack often wins

** Territory holder often wins

** Early success leads to more wins

** Side-ways attack- use claws (& look bigger +fluff)

** No good submission posture - loser should run

** Not usually fight to death, but sometimes, in lab

** 'Pecking order' changes fights to threats

** Pheromones (females are seldom attacked)

Calhoun 'Behavioral Sink' experiment

** 4 connected pens, all with food, water, bedding

** Allow to breed and increase

** alpha males;

*** intermediate males;

**** omega males;

***** 'prober' males

** females & reproductive success

** As population increased, reproductive success declined

** excitement of the sink (Cf. city)

** Interpretation: Breakdown of rat social contract

11/15/96: Agonistic behaviors in the domesticated dog, Canis familiaris, and in the spotted hyena, Crocuta crocuta



** 'Old Exam 3' is in Norlin Reserve, and on Web **

** Class on Wed., Nov 27 is optional. I will attend and discuss term papers, materials already covered, life on the 3rd rock, etc., if any of you wish to attend.

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AGONISTIC Behaviors (cont'd):

Dog (Canis familiaris)

Most breeds of dogs do seem to vie for dominance, by postures, threats, fights, etc.

The competition for dominance seems to be much stronger in dogs than in bitches, though bitches fight too.

Is this aggression related to androgen levels?

**It does seem to be, at least partially. Dogs castrated at birth are less likely to attain high status.

**But, as Beach, and LeBoeuf showed, with beagles, castration after puberty did not preclude a castrate dog from achieving high status --above the status of some intact dogs.

**It is interesting that most adoption agencies insist on castration as part of adoption, but advise waiting until after puberty for the castration.

**LeBoeuf and Beach also reported that their castrates remained interested in sex, although they couldn't 'lock' due to small penis and bulbis glandis.

Why do aggressive tendency and interest in sex remain after post-pubertal castration in dogs?

**-androgen-influenced neural circuits already formed -?

**-aggression and coitus have already been learned -?

**-adrenal androgens continue, and support these activities -?

**-Other -?

Threat postures:

**head up, tail up (tail may be wagging!), staring, ears back, ruff up on neck and back, 'chesty' appearance, low-pitched growl

Submission postures for dog:

**look away; run back a few steps; do not use threat postures; roll belly-up; invite play, with head down between forepaws (bowing) with rump up.

**Dogs often attack with a leap up and toward the other, to be on top

**Some dogs will roll belly-up, to give-up the fight. This is often seen in puppies.

**Some dogs fight with belly up, to use claws on all 4 feet, so belly-up is not always a submission posture

**Exposing neck and belly, and ceasing to fight, seems to work as submission. Fatalities are unusual. The loser often cowers, runs away, etc.

Will dogs fight with bitches?

Yes. They usually investigate for estrus, first.

Will bitches start a fight?

Yes. Often to protect pups, or their territory.

Testicular androgen-influenced?

**Probably. Males usually larger, and early castration seems to reduce both size and aggression.

**But not completely. Females can fight very well. Castrates can fight very well. - Adrenal androgens-?

Pheromones?

**Yes. Note extensive urine marking by males, and extreme sensitivity to estrus urine and other odors.

**Most canids have highly developed, extremely sensitive olfactory systems. e.g., Bloodhounds.

Is Learning involved?

**Probably. Most owners try to train their dogs not to fight, not to bite people. And this works fairly well.

**But dogs can be trained to fight, to attack (e.g., pit bull; guard dogs

Tentative conclusions:

This and related species have evolved to live in groups (packs), have evolved for dominance competition, and for defense of lair and territory. It is likely that both testicular and adrenal androgens are used in support of these behaviors. In lactating females, it is likely that prolactin also plays a role in defense of her litter.

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Spotted Hyena (Crocuta crocuta)

Study of this species tends to broaden our horizons!

Females are larger than males.

Females are dominant to males

Females have external genitalia that mimic those of males, but are even bigger

Hyena pups are extremely aggressive, from birth

How does this happen?

-Apparently this species evolved in such a way that the females secrete large amounts of androstenedione in their uterus, and can convert this to testosterone. Also, the androgens pass through the placenta, to the fetuses. This masculinizes the females very dramatically.

Why does this happen?

Well, this is harder. J.P. Goulds suggests that it originated as a way to give females the aggression they need to compete with other hyenas in the clan -??

Pheromones?

Yes, 'scent pasting' with secretions from anal gland

Postures?

Yes, e.g., a dominant, higher-rank hyena waits, and allows lower rank hyena to come up and sniff. Both tend to erect penis or clitoris, as part of the meeting

Group?

Yes, the clan, of 40 or so. There is pretty intense competion within the clan, but adults usually do not kill one another. Clans do fight each other, and this sometimes results in some deaths.

Jaws?

Can crush and digest large bones of buffalo or cow. Dung is grey-white, from digested bone. Can carry a man or antelope, in jaws.

Submission signals?

There must be, as any adult could bite another one in two.

General conclusions:

Androgens are potent agents for development toward male-like morphology, even in females

Androgens can be potent agents for increasing aggressivity

Androgens can exert their effects on aggressivity even while the cubs are in utero, as it is common for a new- born female to kill her twin almost immediately after birth. It's less common for a female cub to kill her male twin.

11/18/96: Agonistic behaviors in the elk, Cervus elaphus canadensis, and in elephant seals, Mirounga angustirostris

Elk: Student lecturers:

Cervus elaphus canadensis

The stags over-winter in bachelor groups.

They need to browse on nutrient-rich forage, as grasses are not sufficient for their antler growth.

About mid-March each year, they cast their antlers. Sometimes they chew on the cast antlers, indicating they are short of nutrients.

Their new antlers begin growing again almost immediately. They are covered by soft skin, called 'velvet'

When 'in velvet' the stags do not fight much at all. If they are threatened, they use their forefeet and slash with their hooves, keeping the antlers out of the way.

About September, the antlers begin 'cleaning' i.e., they begin shedding the velvet, which comes off in strips of dead skin.

Also about mid-September the stags come into breeding condition, or 'rut'

Until rut, their testes have been small and inactive. Prior to rut, the testes grow and begin function. This is called testicular recrudescence.

Each large stag now tries to establish a rutting ground.

He will urinate in the dirt and on himself, and then roll in the 'wallow' to get scent all over himself.

He may thrash bushes with his antlers, 'bugle' loudly to attract does, and have pushing matches with any other stag who does not back out of his desired rutting ground.

The does are attracted by his bugling, and start to assemble around each large stag.

The stag also 'herds' the does, to help keep them in his harem. He may have several bouts or fights with other stags who won't back down from his threat displays and bugling.

The jousting stags often run together for a hundred yards or so, looking for high ground or other advantage. Then they wheel and attempt to jam their antlers into the other one.

Usually they meet with antlers, and then push back and forth in a test of strength.

When the weaker sees that he is losing, he disengages and tries to run away. If he is not quick, he may get gored.

There does not seem to be a good appeasement posture or gesture. The loser has to get well out of the rutting ground.

The alpha stag with his harem of does will keep herding his does, waiting for their estrus. He loses a lots of weight, as he doesn't have much time to eat.

Sometimes a stag who started rut too early is so weak by the time breeding season starts, that he is displaced by a later-rutting stag, who takes over.

The alpha stag tries to accomplish all breeding in his harem. As part of his testing for estrus, he may put in nose under the urine stream, as a female urinates. He then blows the urine out in a spray. This behavior is called FLEHMEN Some cats do it, too.

It seems to be a way of chemically sampling the urine for estrogen metabolites that indicate the female is in estrus.

After the breeding season, the does form their own herd, consisting of females, and immature elk, and led by a senior cow.

The stags form a loose bachelor herd, and move off to their own browsing grounds.

Elephant seals

Student Lecturers: Laura Hodgkins & Autumn van Kirk

Most of the fighting with elephant seals is among the large males. The females squabble among themselves for room for their pup, etc., but do not really fight.

The males begin 'hauling out' in December each year, and begin vying for dominance with each other. The losers may retreat back into the ocean, and then swim around the island and find a quiet beach where they stay resting and sleeping for most of the breeding season.

By the time the pregnant females and younger seals begin hauling out in January, the good beaches have been each taken over by a powerful alpha male. As the females congregate on the beach, the alpha male will move to their midst and claim the harem. He then spends a lot of his time issuing threats to other males to keep away, or fighting them, if they won't stay away.

If the harem master sees or hears a male challenging him, he will rear up, with nose hanging in his mouth, and bellow back. If that male has previously been vanquished, it will probably retreat. If not, it will probably advance toward the harem. The harem master also advances toward the interloper, stopping to rear and bellow now and then.

When the males meet chest to chest, they swing their head back and forth to swing their long nose out of the way, and try to get a good bite in on the other's neck. The neck has thickened, keratin tissue, on it about an inch thick, but still can be torn and wounded. The bulls also try to bite the other's nose, if possible. When they get a good hold on a nose, they swing it back and forth, shredding it. This is a bad loss for the one whose nose got caught. Occasionally a bull catches his own nose in his teeth, and bites through it. This damage may cause him to back down.

Most fights only last a few minutes before the loser wheels quickly and tries to get away. The winner often gets another bite or two in on the losers rear end or rear flippers, as it flees. The winner then goes back to guarding his harem from the next would-be interloper.

If bulls are evenly matched, say between an alpha bull and a beta, the fight may go on for 30 minutes or so, leaving both quite exhausted. Because of their thick coat of blubber, the animals tend to overheat easily, and have to pause, rest, cool off, and then continue fighting.

Sometimes it seems not to be the best of tactics to become an alpha bull too early, as then he has to fight for most of the season. Since the seals don't eat while on the island, he loses a lot of weight and strength, and may be deposed just before the females come into estrus.

Bulls seem to be in peak form and strength when they are about 9-12 years old. As they age, they will be deposed, but may be able to hold alpha status for a period of a few years.

Because of the heavy protection afforded these animals, not much is known of their hormone levels. We can assume, however, that rising androgen levels are a significant contributor to the fighting spirit of the bulls. For example, all the seals come back to the island around June or July, to molt (shed and renew their fur pelts). At this time there is no fighting and no sex. It seems clear that the males have an annual recrudescence of their testes, with renewed growth in size and function just before the regular breeding season in December-January.

Competition for dominance is apparently an important part of the continuing evolution for elephant seals. It probably contributes to maintenance or continued development of size and strength in the species, as only a few of the most powerful bulls manage to breed each year. And fighting or at least threatening seems to be a prime motive for males in the breeding season. A male will interrupt copulation to go fight.

The size and voice strength of an alpha bull may be an attraction to the females, although it is not really apparent to a watcher. The females seem to aggregate with each other, their pups, and younger seals, into a pod, rather than being attracted to the alpha male. But maybe I missed something, when watching them.

The bull does not seem to herd his females. If one crawls off to another pod, so be it. But this is rare, as the pods are about 70-100 yards apart, and the animals usually do not crawl so far.

The fighting, though bloody and dangerous, does not usually result in the death of a male. The loser usually gives up in time, and gets out of there. They do not seem to have a submission or appeasement posture, except for leaving quickly when they lose.

I never saw a bull fight a female. If a female does not get out of the way, however, when two large bulls are going for each other, she may get rolled or even bitten. The same is true for the pups, who are even less moile, and some may be wounded or even killed by the bulls. This seems to be accidental.

11/20/96: Discussion of parts of Ardrey's The Violent Way

Student Lecturers:



Discussion of agonistic behavior in humans.

Per Robert Ardrey: The Social Contract

Life is competitive. All organisms, including humans, must compete with others to get what they need to survive.

The many manifestations of aggression we see in humans are a natural outcome of evolution and survival of the fittest over many generations.

But, we are a group-living species. Too much aggression against other group members will result in being kicked out of the group. This is detrimental, sometimes fatal.

We therefore have to achieve a balance between having enough aggression to get what we need, but staying within the bounds of custom, decency, laws, etc.

This balance, Ardrey calls the Social Contract.

We have many mechanisms to deal with those who breach the social contract:

Verbal reproof

Pointing out breach to friends, neighbors, strangers

Shunning

Fighting

Jailing

Capital punishment

etc.

And our society has degrees and gradations, for different purposes. E.g.,

Boxing, wrestling, football and other sports

Police

Fighting back when attacked

Armed Forces

Ardrey sees these and other partial exceptions to the usual social contract rules and customs as specialized and limited, for a particular purpose. And the exceptions in turn have their own rules:

Marquis of Queensbury (boxing)

Police procedures (and Review Boards)

Don't be excessive when fighting back

Rules of warfare -? no gas, no torture, feed prisoners, etc.

Another interesting Ardrey thesis is that we evolved our social contract customs and ways of fighting when we were armed with sticks, rocks, swords, daggers, spears, etc. In other words, for one person to do damage to another, they had to be hand-to-hand.

Fighting close at hand means that we have an opportunity to see how much damage has been done, and to see and perhaps respond to submission signals.

With the advent of the bow and arrow, the distance between combatants usually means that we can NOT see how much damage is being done, and cannot see if the opponent want to give up.

Then, with the invention of the cross bow, this distance problem became worse, and worse again with the invention of firearms (and atomics!)

According to Ardrey, this ability to fight at a distance has meant a huge increase in bloodiness and cruelty. In much of war now we are so far removed from the opposing individuals, that we hardly think of them as individuals like ourselves, with families, etc.

Another interesting Ardrey thesis was mentioned before, in connection with the Calhoun rat experiments:

We often love the excitement of combat and war. In the early stages especially, it all seems very exciting, manly, etc. to be going off to fight for country.

It is often the case in later stages of war that individuals begin to realize the cost and suffering.

But: war is still the highest court of appeals. We can try (and often do) discussion, compromise, World Court, United Nations, etc.

But if talking fails, it is not unusual for things to escalate to terrorism, sabotage, blockade or all out war.

In a way, it is surprising that there are ANY rules in war. The competing sides are already trying their utmost to prevail, and 'rules' can hardly be enforced (except afterwards, perhaps)

______

Daniel Funkenstein reported some interesting experiments in which he attempted to find out if there are hormonal correlates for anger and fear, in humans.

Working on a ward with psychotics, Funkenstein noticed that some patients responded very differently to administration of mecholyl to control high blood pressure.

Those patients whose predominant emotion on the ward was fear and timidity showed a long-lasting blood pressure reduction to mecholyl.

Those patients whose predominant emotion was anger directed at others, showed a reduction in BP, but it was short lived and transient: Within about 15 minutes, their BP was up again.

Funkenstein then tried mecholyl on medical students who had just graduated and were awaiting their assignments to internships -- a stressful time.

The young M.D.s who expressed anger and hostility about having to wait to hear, showed the transient response to mecholyl.

Those who were anxious and fearful about getting a bad internship showed the long-lasting response to mecholyl.

Noticing that these different responses to mecholyl were similar to the differential responses in animals to injections of Epinephrine, or Norepinephrine, Funkenstein name the responses 'Type E' (like epinephrine response), and 'Type N' ) like the norepi response.

At this point, he theorized that epinephrine was a correlate of the emotion of fear, and that norepi was a correlate of the emotion of anger.

Funkenstein's theory has been borne out, at least to a degree. E.g., Elmadjian (and others) have infused E or NE into volunteers, to learn what their emotional response would be.

The typical result is that volunteers who (blindly) get E tend to report a feeling of apprehension of fear. They often admit that they can't see what there is to be afraid of (in the lab), but still report feeling fearful. This has been termed 'cold fear'

Those who get NE (blindly) tend to report anger and hostility. Again, they sometimes admit that they can't explain it, but do feel angry. I.e., 'cold anger'.

Section Summary: It appears likely that the brain integrates information from the social surround, and is able to send differential signals to the adrenal medulla, to release more E (when fear is useful), or more NE (when anger is useful).

The differential neural pathway is just beginning to be understood, anatomically. It is interesting that behavior studies first pointed out the likelihood.

_______

In most human societies, if not all, it is much more common for males to express physical aggression. And it has long been known that the higher levels of testosterone are a partial basis for this. E.g.,

-castration reduces fighting in most species, including man

-women with high androgens are more likely to show physical aggression

-treatment with anti-androgens has had some limited success, for aggressive criminals

-a recent report comparing MZ twins who were different for measured aggression found that the more aggressive had higher testosterone.

Section summary:

It appears likely that androgens have been put to use as substrates for overt aggression, in many species, including ours.

________

Some food for thought:

It is typical in most families to teach less aggression (Don't hit your sister) (Stop playing so rough) (Never gouge anybody's eyes - you might blind them)

It appears that we, especially boys, have considerable drive toward physical aggression, and this has to be toned down, to fit the social contract.

It is also interesting that early on we learn rules about fighting fair / fighting dirty:

Do not poke eyes

Do not bite

Do not rip nostrils

Do not hit testicles

Do not use rock / broken glass etc.

Do not continue pounding if opponent gives up

These seem to be part of the social contract: compete as necessary, but don't cause death or lasting harm

It is also interesting that specialized branches of police and military give specific training to forget the above rules:

Crush the windpipe

Gouge the eyes

Rip the nostrils upward

Bite anytime it can help

Attack the testicles

Use any weapon you can get your hands on

Kill your opponent (in certain circumstances)

It has often been remarked that fights usually begin with an 'incitation' stage. Before the actual fight there is name calling, pushing and shoving, puffing up, threats, insults (spitting in face, slapping with glove/hand, coward, sissy, etc). It appears that the incitation stage serves to increase testosterone release (and maybe NE release), to help bolster the man in the upcoming fight.

Some correlates of higher testosterone levels:

-Winning a physical competition by skill (tennis)

-Winning a fight (loser has lower T)

-Winning a prize, by ability and drive

-Exerting dominance in an earned position (board chairman, military officer or non-com)

If success is seen to be luck, not skill, then there is usually no rise in T

Close, hard-fought tennis matches, decided by a point, usually show no rise in T, for winner

Winners of games decided by chance usually show no rise in T

Winning by cheating usually shows no rise in T

It appears that we have to win fairly (within the social contract), by strength and skill, to get the rise in T

What about women?? -Much less is known, alas. Woman can of course be fierce competitors, Do they get support from adrenal NE and E - probably. Do they get support from adrenal androgen release. I don't know. It seems probable.

11/22/96: Review



11/25/96: EXAMINATION 3

______________________________

11/27/96: No required class meeting. General class discussion of previous material, for those who attend.

11/29/96: Thanksgiving holiday

12/2/96: Begin Phase IV - Current Findings