Occurrence of placental scars in the uterus of the african elephant (loxodonta africana)
About: This article is published in Reproduction.The article was published on 1967-12-01 and is currently open access. It has received 20 citations till now. The article focuses on the topics: African elephant.
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TL;DR: A short record of the history and aims of the Nuffield Unit of Tropical Animal Ecology and only a superficial review of the research done is included, though a full list of publications is appended.
Abstract: Synopsis. This article has been composed at the request of the Committee of the Nuffield Unit of Tropical Animal Ecology (NUTAE) at its final meeting in Cambridge in October 1971 and has benefited from the comments of the Committee Members and the two successive directors. It is a short record of the history and aims of the Unit and includes only a superficial review of the research done, though a full list of publications is appended. It refers to the ten years ending in 1971 during which it was basically financed by the Nuffield Foundation and after which it was transferred to the Uganda Institute of Ecology. For an account of the previous development of interest in conservation and research on African wildlife see Worthington, E. B. (1961). The wild resources of East and Central Africa. London. H.M.S.O.
4 citations
TL;DR: Dick Laws was the leading marine mammalogist of his generation, developing in the Antarctic new techniques and approaches to population studies, notably with elephant seals and great whales, and leaves an unrivalled legacy to the population ecology and management of large mammals and to the science, conservation andmanagement of the Antarctic.
Abstract: Dick Laws was the leading marine mammalogist of his generation, developing in the Antarctic new techniques and approaches to population studies, notably with elephant seals and great whales. He later pioneered similar approaches with large mammals, especially elephants, in Africa before returning to the UK as Head of Life Sciences, then Director, of the British Antarctic Survey (BAS). His inspirational and unequivocal leadership saw BAS and its science develop and flourish, both in difficult times and through the major reorganization and expansion to fulfil its enhanced role and responsibilities after the Falklands conflict. He was a staunch supporter and leading advocate of the Antarctic Treaty System and was hugely instrumental in the development of the Convention for the Conservation of Antarctic Seals and of the Convention on the Conservation of Antarctic Marine Living Resources. He led the Scientific Committee on Antarctic Research (eventually as its president) into ground-breaking collaborative programmes of research into the biological oceanography of the Southern Ocean in support of the sustainable management of its living resources. On retirement from BAS he became Master of St Edmund9s College, Cambridge, presiding over its transition to an institution fully integrated into the collegiate system of the university. He also served with distinction in Cambridge University affairs generally. An imposing and charismatic individual of total probity and conviction, loyalty and dedication, greatly admired by friends and colleagues, respected by opponents, he leaves an unrivalled legacy to the population ecology and management of large mammals and to the science, conservation and management of the Antarctic.
3 citations
TL;DR: It was determined that giving birth and being exposed to herd mates entering the facility were positively associated with normal ovarian cycle and prolactin profiles, whereas age, serum cortisol, and an increased number of herd mates leaving a facility were negatively associated with both.
2 citations
01 Sep 2012
2 citations
TL;DR: In this article , the authors examined the relationship between reproductive state and movement using GPS tracking data collected during 23 parturitions from multiparous elephants (≥ second calving) and three from primiparous females and used a three-state hidden Markov model to determine whether parturition results in a distinctive change in speed.
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TL;DR: The findings are discussed with reference to the phylogenetic position of the genus, the probable role of the corpus luteum in pregnancy, and the significance of the results in relation to the conservation of existing wild elephant populations.
Abstract: Between December 1946 and December 1948, and January to March 1950, 150 elephants made available in the course of control work carried out by the Uganda Game Department were examined in greater or less detail according to circumstances. Eighty-one were females, of which sixty-seven were adult and thirty-one had an embryo in the uterus. All the dissections were carried out in the field, and the present account includes observations on the terrain, the food of the elephant, and other aspects of its ecology. Linear measurements of the carcasses and photographs of the molar teeth provide a guide to the age of specimens. Tusk growth is nearly similar in males and females until puberty, after which those of females generally cease to grow. The reproductive organs of the male are briefly described; those of the female are described in more detail, and discrepancies between existing accounts are considered in the light of this relatively extensive series of specimens. The mode of formation of the ovarial sac is unusual and is described from foetal, neonatal and adult specimens. There is marked hypertrophy of the interstitial tissue of the foetal gonads during the later stages of gestation. Breeding occurs at all times of year, but mating is possibly more frequent in the period December to March than at other times. Both sexes reach maturity at 8 to 12 years, and the female continues to breed until old age. Parturition is followed by a lactation anoestrus, after which the female undergoes a number of brief oestrous cycles until pregnancy ensues, lactation being continued throughout the subsequent gestation period. The interval between parturition and subsequent conception is normally of the same order of duration as the gestation period, and the normal calving interval appears to be rather less than four years. The ovarian cycle of the adult is characterized by the occurrence of multiple ovulation and the presence of many apparently active and histologically indistinguishable corpora lutea in both ovaries at all the stages of pregnancy which were encountered. It is probable that the corpus luteum of pregnancy develops from one of a number of follicles which ovulate under the same hormonal stimulus, and that it persists together with the accessory corpora lutea, some of which arise from follicles which ovulate and some from follicles which luteinize without ovulating. The corpora lutea are replaced about mid-pregnancy by a second set, which are formed by the luteinization of all the follicles with antra in both ovaries; some at least of the larger ones ovulate while many smaller ones do not. Follicular growth is suppressed in the later stages of pregnancy. The cycle of events bears some resemblance to that which occurs in the mare, and the comparison is discussed in detail. The ovarian periphery is characterized by numerous subsurface crypts and papillose projections which increase the area of the germinal epithelium. A description of the placenta and foetal membranes is in preparation, and preliminary study reveals a striking similarity to Hyrax , particularly in the quadri-lobulate allantois. The findings are discussed with reference to the phylogenetic position of the genus, the probable role of the corpus luteum in pregnancy, and the significance of the results in relation to the conservation of existing wild elephant populations.
123 citations
"Occurrence of placental scars in th..." refers background or methods in this paper
...INTRODUCTION The elephant placenta is vasochorial, rather than, in the strict sense, endotheliochorial (Amoroso & Perry, 1965) and as Perry (1953) remarks in an earlier paper: "It is clear . . . that a considerable amount of maternal tissue comes away with placental tissue of foetal origin when the…...
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...For Western Uganda the material collected by Perry (1953) indicated a Downloaded from Bioscientifica.com at 04/27/2019 02:50:21PM via free access Placental scars in the elephant 449 mean calving interval of 3-8 years in the years 1947 to 1950; current research on the same populations suggests that…...
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...The elephant placenta is vasochorial, rather than, in the strict sense, endotheliochorial (Amoroso & Perry, 1965) and as Perry (1953) remarks in an earlier paper: "It is clear ....
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...For Western Uganda the material collected by Perry (1953) indicated a...
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