Sexual behaviour of male and female tammar wallabies(Macropus eugenii)at post-partum oestrus

1994 ◽  
Vol 232 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Carl D. Rudd
1967 ◽  
Vol 54 (2) ◽  
pp. 227-240 ◽  
Author(s):  
F. Neumann ◽  
J. D. Hahn ◽  
M. Kramer

ABSTRACT Male newborn rats were injected with 2 mg of an antiandrogen (1,2α-methylene-6-chloro-pregna-4,6-dien-17α-ol-3,20-dione-17α-acetate = cyproterone acetate) daily from their 1st to their 14th day of life. The following effects of this treatment were observed in these animals after onset of sexual maturity: 84% of the animals are unable to reproduce. Penis: the frenulum is broadened to a lamina of triangular shape, which almost completely prevents the preputium from being pushed back. These males show a rather insufficient male sexual behaviour towards females in oestrus. After castration and ovar implantation, some of the treated animals show true corpora lutea and at attempts of cohabitation partially female sexual behaviour towards normal male animals. From these results it can be concluded, that differentiation of the penis is not completed at the time of birth. The infertility of the animals may be caused by the penile changes (difficulties with intromission) as well as by the aimless sexual behaviour. This aimless sexual behaviour, the ability to produce true corpora lutea and finally their partially female sexual attitude under the influence of the hormones from the implanted ovaries led to the conclusion, that the above described neonatal treatment apparently inhibited testosterone-depending post partum developments of sexual differentiation in hypothalamic centers.


2001 ◽  
Vol 49 (1) ◽  
pp. 37 ◽  
Author(s):  
Shan Lloyd

Wild-caught male and female H. moschatus were maintained in a captive breeding colony. Vaginal smears were taken three times a week until oestrous cycles were detected and gestation lengths approximated. Thereafter, smears were usually taken daily when oestrus was expected. The gestation period (considered to be the number of days from the detection of sperm in the smear until the day young were found in the pouch) was found to last 19 days. Sperm were usually detected in the smear two days before the influx of semi-cornified and cornified epithelial cells, which occurred 17 days before parturition. A pre- or post-partum oestrus was not detected and females did not return to oestrus until at least 6 days after the removal of the last pouch young. H. moschatus has the shortest recorded gestation for any macropod, and gestation occupies approximately 75% of the oestrous cycle. The reproductive physiology of H. moschatus is similar to that of most phalangerids, which may be indicative of a common ancestor.


Author(s):  
Leigh W. Simmons

‘Sex roles and stereotypes’ examines the notion, implicit in many of the original ideas about sexual selection, that males and females have natural ‘roles’ with characteristic behaviour associated with each sex. It also explores further the reasons behind deviations from the ‘typical’ sex roles in mate choice and in mating competition. Are there ‘standard’ male and female roles in both humans and other animal species? One version of sex roles holds that males are generally dominant and females submissive, stemming from the way that sexual selection favours different behaviours in each sex. This could mean that sexual selection dictates particular behaviours in males and females. But in fact, sexual behaviour is extraordinarily varied in nature.


1997 ◽  
Vol 9 (2) ◽  
pp. 243 ◽  
Author(s):  
K. Basden ◽  
D. W. Cooper ◽  
E. M. Deane

A study has been made of the development of four lymphoid tissues from birth to maturity in the tammar wallaby Macropus eugenii —the cervical and thoracic thymus, lymph nodes and gut-associated lymphoid tissue (GALT). The development of these tissues in the tammar wallaby is similar to that in two other marsupials, the quokka Setonix brachyurus and the Virginian opossum Didelphis virginiana. Lymphocytes were first detected in the cervical thymus of the tammar at Day 2 post partum and in the thoracic thymus at Day 6. They were subsequently detected in lymph nodes at Day 4 and in the spleen by Day 12 but were not apparent in the GALT until around Day 90 post partum. By Day 21, the cervical thymus had developed distinct areas of cortex and medulla and Hassall’s corpuscles were apparent. The maturation of other tissues followed with Hassall’s corpuscles in the thoracic thymus by Day 30 and nodules and germinal centres in the lymph nodes by Day 90. Measurement of immunoglobulin G concentrations in the serum of young animals indicated a rise in titre around Day 90 post partum, correlating with the apparent maturation of the lymphoid tissues.


1990 ◽  
Vol 2 (1) ◽  
pp. 79 ◽  
Author(s):  
TP Fletcher ◽  
G Shaw ◽  
MB Renfree

Female tammar wallabies were treated with the dopamine agonist bromocriptine at the end of pregnancy to suppress the peripartum pulse of plasma prolactin. The animals were subsequently observed, and a series of blood samples taken to define the hormonal profiles before and immediately after parturition. Birth was observed in 4/5 control animals and occurred in 8/9 bromocriptine-treated animals. The peripartum peak in plasma PGFM concentrations was not affected by bromocriptine although the pulse of prolactin normally seen at parturition was completely abolished. The timing of luteolysis was apparently unaffected, as plasma progesterone concentrations fell similarly in both treated and control animals immediately after parturition. However, all of the neonates of the bromocriptine-treated animals died within 24 h, possibly because of a failure to establish lactation. Subsequent onset of post-partum oestrus was delayed or absent both in control and in bromocriptine-treated animals, suggesting that the frequent blood sampling and disturbances in the peripartum period interfered with these endocrine processes. It is concluded that both prolactin and prostaglandin can induce luteolysis in the pregnant wallaby, but that the normal sequence of events results from a signal of fetal origin inducing a prostaglandin release from the uterus, which in turn releases a pulse of prolactin that induces a progesterone decline.


1974 ◽  
Vol 63 (3) ◽  
pp. 483-488 ◽  
Author(s):  
M. DALLE ◽  
P. DELOST

SUMMARY Concentrations of cortisol and corticosterone in the plasma and adrenal glands of male and female guinea-pigs were estimated throughout the first postnatal day and thereafter at intervals up to 3 weeks of age. In the guinea-pig, the basal level of cortisol secretion is established more slowly than in other species. The concentration of plasma cortisol is very high at birth, with a marked fall between days 1 and 10 post partum and then a steady level from day 10 to 20, the time of weaning. At day 10 the values for plasma cortisol and corticosterone approach the lower ones found in the adult. There were peaks in the amounts of corticosteroids found in the adrenal gland at 50 h, 4 and 7 days and these may have been due to increased hormonal synthesis between days 2 and 8.


1977 ◽  
Vol 75 (1) ◽  
pp. 173-174 ◽  
Author(s):  
VERONICA A. CERNY

Laboratory of Anatomy, Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A. (Received 28 March 1977) Testosterones have stimulatory effects on peripheral target tissue and sexual behaviour in male and female rats (Beach, 1942), guinea-pigs (Young, 1961; Diamond & Young, 1963), rabbits (Palka & Sawyer, 1966; Beyer & Rivaud, 1973) and cats (Green, Clemente & de Groot, 1957; Young, 1961; Whalen & Hardy, 1970). 5α-Androstan-17β-ol-3-one (dihydrotestosterone, DHT) has stimulatory effects on peripheral target organs, and like testosterones, a negative feedback effect on the pituitary gland and hypothalamus (Feder, 1971). No behavioural effects were seen in male or female rats when DHT was injected systemically (Beyer, Morali & Cruz, 1971; Feder, 1971) nor in the male rat when it was administered intracerebrally (Johnston & Davidson, 1972). Many experiments support the hypothesis that only androgens that can be aromatized to oestrogens can elicit sexual behaviour and


1961 ◽  
Vol 22 (4) ◽  
pp. 335-348 ◽  
Author(s):  
FLORENCE J. PEPPER

SUMMARY The behaviour of the superficial lymph nodes differs from that of the thymus gland during the various phases of life of the mouse. In male and female Strong A mice the thymus gland regresses with age, but the superficial lymph nodes do not. During pregnancy the thymus undergoes an accelerated temporary regression, but regenerates soon after the end of the lactation period (earlier in non-lactating post-partum females). The superficial lymph nodes show a lesser temporary regression which, however, does not become evident until after parturition. Their regeneration occurs after the lactation period, and after a corresponding period in non-lactating post-partum females. The difference in behaviour of the thymus and of the superficial lymph nodes is probably an indication of the greater sensitivity of the thymus to the increased output of adrenocortical hormones which occurs during pregnancy. Repeated injections of cortisone acetate into the intact animal induce a response in the thymus gland and superficial lymph nodes similar to that evoked by pregnancy.


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