1312 



HORMONAL REGULATION OF BEHAVIOR 



Behavior during and just after parturi- 

 tion is thus a mutual affair, involving the 

 structure and behavior both of the mother 

 and of the neonate. Young mammals vary 

 widely with respect to the level of develop- 

 ment at birth, some being born very small, 

 blind, and helpless, others larger, well 

 furred, and ready to take solid food within 

 a day or two after birth (Hamilton, 1939). 

 The young of some s]:)ecies are not capable 

 of standing or walking for some time after 

 birth, and thus can suckle only while lying 

 under the mother (Wiesner and Sheard, 

 1933; Schneirla, 1956). The young of other 

 species can stand almost immediately after 

 birth and characteristically suckle in a 

 standing position (Altmann, 1952; Hediger, 

 1952) . Clearly the behavior of the immedi- 

 ately i:)ostparturitive mother and that of the 

 neonate must be adapted to each other. It 

 will be recalled that the mother goat licks 

 the newborn kid as the kid is leaving her 

 body. After parturition, the (standing) 

 mother continues to lick the kid, which is 

 also standing, licking along the kid's back 

 to its anus which is especially vigorously 

 licked. When the mother is licking in the 

 neighborhood of the kid's anus, the head of 

 the kid is in the neighborhood of the moth- 

 er's teats, and according to Blauvelt (1955), 

 this arrangement of the licking behavior 

 contributes to the first establishment of 

 suckling. Somewhat similar observations are 

 recorded by Altmann (1952) in the Ameri- 

 can elk. As Schneirla (1956) describes the 

 behavior of the domestic cat during par- 

 turition, intervals of intense activity which 

 facilitate the expulsion of the fetuses are 

 interspersed with intervals of exhaustion 

 and rest, which facilitate the initiation of a 

 suckling relationship between the mother 

 and the neonate. The neonate is brought into 

 contact with the abdomen of the mother 

 partly through the behavior of the mother 

 (licking, lying down, etc.), and partly by 

 its own crude orienting responses to tactual 

 and thermal stimuli from the mother (Ro- 

 senblatt, cjuoted by Schneirla, 1956). Ro- 

 well (1960a) has made similar observations 

 on the golden hamster. 



Although information on behavior during 

 parturition, and on the very earliest stages 

 of mother-young relationship, are available 

 for only very few species of mammals, it is 



apparent that a wide variety of patterns of 

 such behavior can be found in nature, and 

 that a great deal yet remains to be learned 

 about them. 



2. Physiologic Aspects of Parturitive Be- 

 havior 



In many species of mammals the mother, 

 after licking herself and the emerging 

 young, may tear the fetal membranes, bite 

 through the umbilical cord, and eat the 

 placenta. Placentophagy is widespread, oc- 

 curring in many different families and or- 

 ders. Thus the habit of eating the placenta 

 is found among such widely differing mam- 

 mals as bats (Allen, 1939; Wimsatt, 1945; 

 Ramakrishna, 1950), ungulates (Hediger, 

 1942, 1955), rodents (Eibl-Eibesfeldt, 1958; 

 Dieterlen, 1959), carnivores (Tembrock, 

 1957), monkeys (Tinklepaugh and Hart- 

 man, 1930; Carpenter, 1934), chimpanzees 

 (Yerkes, 1935; Nissen and Yerkcs, 1943), 

 and others. 



Placentophagy is, however, by no means 

 universal. In species in which it does occur, 

 it may not occur in every case. For example, 

 Nissen and Yerkes (1943) report that of 

 29 chimpanzee births observed by the au- 

 thors, the whole placenta was eaten in 13 

 cases, bits of the placenta in 4 cases, and 

 there was no eating of the placenta in 10 

 cases. In all 29 cases, however, the fluids 

 associated with the placenta and amnion 

 were licked up from the floor and from the 

 infants. The camels and their relatives nei- 

 ther lick the young nor eat the placenta 

 (Filters, 1954; Koford, 1957). In a number 

 of aquatic animals, such as seals (Slijpcr, 

 1956), dolphins (McBride and Hebb, 1948; 

 Tavolga and Essapian, 1957), the hippo- 

 potamus (Slijpcr, 1956), etc., the mother 

 pays no attention to the placenta, neither 

 licking it, eating it, or touching it, although 

 she may in some of these animals bite 

 through the cord. 



It will not have escaped the attention of 

 the reader that some of these animals which 

 eat the placenta are, at all other times of 

 their life, strictly herbivorous. Hediger 

 (1955) describes how various ungulates, im- 

 mediately after having given birth, "fall on 

 the amniotic sac and devour it." He adds, 

 "in this situation, the most decided herbi- 

 vore turns carnivore all of a sudden. I saw 



