Doctoral Degrees (Zoology)

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The herpetology of south-east Africa.
(1966) Broadley, Donald George.; Poynton, John Charles.
No abstract available.
A review of the old world genera of Lauxaniidae (Diptera)
(1971) Stuckenberg, Brian Roy.; Bush, S. F.; Heeg, Jan.
This paper presents in key form a review of the Old World genera of Lauxaniidae. Thirteen new genera are erected, three genera are placed in synonymy, four subgenera are given generic status, and one genus is transferred from the Heleomyzidae. The development of lauxaniid generic classification is reviewed and a total of 126 recognised genera is obtained. An account is given of the regional distribution of Lauxaniidae; three main faunal aggregates are distinguished, namely the Neotropical, Holarctic and Old World tropical. The validity of certain characters for generic classification is discussed, and the suggestion is made that trigonometopine forms have evolved polyphyletically as adaptations for life in grass and comparable vegetation types. A division of the family into major groups of genera is considered, and a subfamily Homoneurinae is established. The validity of characters used to distinguish Cestrotus and Turriger is examined; a failure to find reliable characters results in the synonymy of the latter genus. Illustrated descriptions are given of the type-species of new genera.
The sea turtles of South East Africa.
(1973) Hughes, George R.; Heydorn, A. E. F.
Abstract available in PDF file.
Aspects of the biology and ecology of the estuarine fishes of the east coast of South Africa.
(1974) Wallace, John Henry.; Heydorn, A. E. F.
No abstract available.
Reproduction and population ecology of the blue wildebeest Connochaetes taurinus taurinus in Zululand.
(1977) Attwell, Charles Anthony Mallory.; Meester, Jurgens Anthonie Jansen.; Hanks, John.
A two-year study was made of the blue wildebeest Connochaetes taurinus taurinus in Zululand, Natal. Aspects investigated included age determination methods, growth and condition, reproductive physiology, habitat interactions, and population dynamics. Findings were related to suggested management of the species.
Ecological and systematic relationships in Natal ranids (Rana Linn. sensu stricto and sensu Strongylopus Tschudi) with notes on a possible competitor, the leptodactylid Heleophryne natalensis Hewitt.
(1977) Channing, Alan Eric.; Van Dijk, D. E.
No abstract available.
Comparative studies on related free-living and pathogenic limax amoebae with particular reference to Naegleria.
(1977) Lastovica, Albert Joseph.; Meester, Jurgens Anthonie Jansen.
Over two hundred and forty strains of limax amoeba including eight potentially pathogenic strains of Naegleria and Acanthamoeba were isolated from a variety of habitats in South Africa. The amoeboid and flagellate stages of all Naegleria strains examined by light microscopy were found to be similar in morphology. Differences were noted in the excystment of Naegleria fowleri, Naegleria gruberi and other limax amoebae. Time-lapse microcinematography has been utilised to study cytokinesis and motility in the amoeboid and flagellate stages of Naegleria fowleri and Naegleria gruberi. A new phenomenon was observed in Naegleria where amoebae attempted cytokinesis after brief exposure to a temperature of 9°C. The amoeboid and flagellate stages of virulent and avirulent Naegleria were found to be similar in surface topology when examined under the scanning electron microscope. Differences were noted in the excystment patterns of various limax amoebae. No structure suggestive of a surface active lysosome was found in any of the cells examined. A comparative transmission electron microscope study of virulent and avirulent Naegleria and other limax amoebae has revealed striking similarities as well as sharply defined ultrastructural differences. Partioles suggestive of a virus were detected in several of the pathogenic Naegleria. Surface-active lysosomes were not found in any of the amoebae examined. Distinct feeding preferences were evident in Naegleria fowleri and Naegleria gruberi when they were tested on a variety of gram-negative and gram-positive bacteria. Differences were noted on the growth of these amoebae at various temperatures. Cell fractions of Pseudomonas aeruginosa affected excystment, encystment, cell division and the amoeba-to-flagellate transformation in Naegleria. Differences were observed in the transformation kinetics of Naegleria fowleri and Naegleria gruberi at 25ºC and 43º C. A variety of inhibitors affected motility and transformation in Naegleria. For the first time, La[3+]ion, a competitive inhibitor of Ca[2+]ion, was shown to inhibit amoeboid motion, transformation and flagellar beating in Naegleria. Electron microscope observation suggested that La[3+]ion acts on the plasmalemma. Material from two suspected cases of primary amoebic meningoencephalitis was examined and cultured but no limax amoebae were isolated. New criteria for the classification of virulent and avirulent Naeglerid. have been advanced.
The Squamata (Reptilia) of the Orange Free State, South Africa.
(1977) De Waal, Schalk Willem Petrus.; Meester, Jurgens Anthonie Jansen.
This study deals with the three orders of Squamata (Sauria, Amphisbaenia, Serpentes) of the Orange Free State, South Africa. Following an intensive systematic survey 4 492 specimens have been examined comprising 77 different species and subspecies of which 25% represent new records for the study area. Variation in taxonomically important characters as well as informa- tion on colour, size, habitat, breeding, predators and diet are discussed. Certain taxonomic changes have been made. Distribution maps have been compiled on the basis of eighth-degree-units. Distributional patterns have been analyzed to establish areas of relative homogeneity separated by transitional zones. A causal analysis of the main distribution patterns of the O.F.S. Squamata indicated that rainfall is the major environmental factor influencing distribution. A comparative analysis of the squamate areas has been done with regard to various biogeographic phenomena.
Aspects of the biology of the red bishop Euplectes orix and other Euplectes species.
(1977) Craig, Adrian John Fergus Knott.; Maclean, Gordon Lindsay.
The breeding biology and the annual cycle of the Red Bishop Euplectes orix was studied over a two year period in Natal. Some comparative data were also gathered for the related species the Red-shouldered Widow E. axillaris and the Red-collared Widow E. ardens, and additional data from a ringer in Rhodesia have been analysed. The breeding season of these polygynous ploceids coincides with the summer rainy season, and the amount of breeding activity in the Red Bishop appeared to be correlated with the amount of rain during the previous year. Breeding success at the colony studied was low; predation was the major cause of nest failure. In all three species the entire population, including the juveniles, undergoes a complete moult at the end of the breeding season. There is some evidence that the birds may make local movements during the winter dry season. These species are sexually dimorphic, the males being larger than the females. The population sex ratio was Significantly biased in favour of males in the Red Bishop and the Red-shouldered Widow but not in the Red-collared Widow. However, about half the male birds are subadults which do not breed, so that there is an excess of females in the breeding population. Adult males undergo a partial moult at the start of the breeding season and acquire a distinctive nuptial plumage. This is shed again at the post-nuptial moult, and in eclipse plumage they resemble the females. There is a similar pattern of weight change in all three species, with peaks early in the breeding season and again during the moult. The lowest annual weights are recorded during the dry season. The mortality rate of the Red Bishop is not high for a small passerine. The findings of this study are compared with the available information on other members of the genus, and discussed in relation to the evolution of polygyny in the Euplectes species.
The mammals of the Transvaal.
(1978) Rautenbach, Ignatius Lourens.; Meester, Jurgens Anthonie Jansen.
The primary object of this study is to provide a checklist of the mammals occurring within the Transvaal. A general biological account of each species forms the bulk of this treatise, - discussing, in order of sequence, firstly the taxonomic status of each species as based on a study of available museum specimens. Thereafter the distribution of each species is discussed, and illustrated with a map of known distribution. Remarks are presented on the various environmental factors that may influence individual species ranges. Habitat preferences, habits, and food preferences are then discussed. Available data on breeding seasonality, as based on the monthly ratio of reproductively active and inactive females, are given. External measurements and masses of males and females are tabulated. Records of occurrence based on the number of museum specimens from each locality, and the institution where these specimens are housed, are finally listed for each species. The text is supplemented by a gazetteer, giving the latitudinal and longitudinal coordinates of all the collecting localities. This study is based on some 12 000 museum specimens, the greatest majority housed in the Transvaal Museum collections. During the field work phase of this project, 57 localities were sampled. This yielded the majority of the specimens and the greater part of the data on which this book is based. Information gained from a study of earlier collected material supplements these data files. Additional information such as sight records, field observations, and the published accounts of other scientists, have also been incorporated into the central data files and have been discussed in relation to my own findings. The results of selected studies comprise the discussion. The basic behavioural trends and mean mass of all the carnivore species of the Transvaal are employed to speculate on how interspecific competition is avoided. The distribution of all southern African mammals is employed to statistically evaluate the validity of the biotic zones previously empirically recognized for this subcontinent. The distribution patterns of Transvaal mammals are statistically analysed to subdivide the biotic zones overlying the Transvaal into community types of zoogeographical significance. Other zoogeographical phenomena are discussed in relation to regional species diversity. Reprints of papers arising from this study, and particularly the discussion, are bound in as appendices to this report.
Systematics and bionomics of the scorpions of South West Africa (Arachnida, Scorpionida)
(1978) Lamoral, Bruno H.; Heeg, Jan.; Meester, Jurgens Anthonie Jansen.
All the taxa of scorpions previously described from South West Africa are revised and a monographic account presented with phylogenetic and biogeographic discussions and conclusions derived in terms of current concepts in systematic zoology which include cladistics and historical biogeography. South West Africa is treated as a subregion of the Afrotropical region and the limits of this subregion coincide broadly with the political borders. All the characters used are defined and illustrated. Many characters previously unstudied for the fauna are investigated. These include comparative studies of trichobothria distributions and detailed structures of the hemispermatophore. Disc electrophoresis of the haemolymph of a few species was carried out and the results discussed. Ecological factors are extensively described and discussed. The nature of the substratum, taken in its broadest possible definition, was found to be the most important single factor determining species distribution. 70 subgeneric taxa were revised, 45 of which are retained as valid, while 11 new species are described bringing the number of known species to 56. These are distributed among seven genera as follows: Buthotus, two species; Karasbergia, one species; Parabuthus, 14 species; Urop1ectes, 10 species; Hadogenes, three species; Lisposoma, two species; Opisthophthalmus, 24 species. Determination keys are provided for all levels of taxa occurring in South West Africa.
An outline of the ecology and behaviour of the red lechwe (Kobus leche leche Gray, 1850)
(1979) Williamson, Douglas Templin.; Meester, Jurgens Anthonie Jansen.
In a number of publications serious concern has been expressed about 'the status of lechwe in the Kwando/Linyanti/Chobe system. Concern has also been expressed about the effects of possible water extraction from the Okavango Delta on the habitat of lechwe in the delta. This study was motivated by this concern and was undertaken to provide information that would facilitate the conservation and management of lechwe in Botswana. Continuous field work on the western edge of the Linyanti Swamp began in January 1975 and ended in May 1977. Follow-up visits were made in February/March and September/October 1979. Data were collected on the following: variation in water l6vels, physiognomic and floristic characteristics of lechwe habitat, age determination, food habits, habitat use, distribution,condition growth, reproduction, non-social behaviour, social behaviour and organjsation and population status. From data collected it was concluded that, although there was no indication of a drastic population decline, the prevailing high water levels in the system were causing a downward trend in the population by pushing the animals into poorer quality habitat. The decline in the quality of the habitat available to the population was reflected by high juvenile mortality and reduced fecundity of young females. On the basis of the findings of this study a strategy for the conservation and management of lechwe in the Linyanti Swamp is proposed.
The population dynamics of impala (Aepyceros melampus Lichtenstein) in Mkuzi Game Reserve.
(1979) Vincent, John.; Meester, Jurgens Anthonie Jansen.; Jarman, Peter.
The need to understand the dynamics of the impala population in Mkuzi Game Reserve arose during the early 1960's when it became clear that various factors were contributing to an overpopulation of the species in the reserve. Population management was recognized as being necessary and was carried out, but it was based on inadequate information. This study set out to establish a rational basis for future management. The social organization and behaviour of impala in Mkuzi were analysed and placed in perspective relative to the population dynamics. Two methods of counting the animals were used and a relationship obtained between the respective results. The distribution of impala within the reserve, both on a gross population basis and with respect to the various sex and age categories, was determined from sampling. In order to establish the age structure of the population, samples obtained from the control programme were used, and these were aged on the basis of molar wear. At the same time the proportions of young animals and the population sex ratios were obtained by field sampling. Using these data, life tables were constructed, from . which it was possible to interpret the behaviour of the population at the time of the study. However, caution should be exercised in extrapolating these results literally to the same population under different conditions. The study only provides guidelines for regular monitoring to be carried out. At the same time a more detailed study of the vegetation dynamics of Mkuzi Game Reserve is a priority so that the relationship between the animal and plant elements of the reserve can be properly analysed.
The incidence of helminths in pigs, sheep, cattle, impala and blesbok in the Transvaal.
(1980) Horak, Ivan Gerard.
The seasonal fluctuations in the worm burdens of pigs, sheep, cattle, impala and blesbok exposed to infestation on improved or natural pastures in the Transvaal were determined. The prevalence of infestation in pigs slaughtered at the Pretoria Municipal Abattoir and in impala near Pafuri and blesbok at Badplaas was also established. Sheep, goats and cattle were successfully artificially infested with a number of nematodes of impala origin and sheep with those of blesbok origin. The various methods used to determine the seasonal incidence of helminth parasites are discussed and the wastage of valuable material criticised when complete recoveries of both internal and external parasites are not attempted at each necropsy. Host specificity and the distribution of parasites according to climate and the zoogeographical distribution of their hosts are discussed and the epizootiology of the major nematode genera parasitizing sheep, cattle, impala and blesbok in the Transvaal is determined. The phenomenon of arrested development in nematodes is compared with that of diapause in insects and measures to control helminth parasites 1n domestic stock and antelope in the Transvaal are suggested.
Aspects of the biology and population dynamics of freshwater mussels in Lake Kariba and Lake McIlwaine.
(1980) Kenmuir, Dale Harold Stafford.; Heeg, Jan.
Following preliminary observations in 1975 the Lake Kariba Fisheries Research Institute implemented a research program in March 1976 to investigate various aspects of the biology and population dynamics of the mussel crop of Lake Kariba, with a view to greater understanding of their status in the lake, and establishing a basis for management, if required. Aspects investigated were densities, distribution, species composition, predation by fish, reproduction, age and growth, gross biochemical composition and crude production rates. The mussel community comprised four species, a small pill clam, Corbicula africana, and three mussels, Caelatura mossarnbicensis, Aspatharia wahlbergi and Mutela dubia. Only the latter three were studied. Mussel beds occupied all the gently shelving cleared and uncleared areas, and the bulk of the populations occurred from 3 m - 9 m depth, but extending to 11 m. Predation by fish was found to be extremely low. The reproduction study showed two species bred all year C. mossambicensis and M. dubia, whereas A. wahlbergi bred seasonally during the rainy season. The two year-round breeders were repetitive spawners, capable of breeding several times a year. Indications are that A. wahlbergi is essentially a fluviatile species, with a life cycle adapted to taking advantage of riverine conditions. Sex ratios in all three species were approximately 1 : 1 , with females predominating slightly. Fecundity in one species, C. mossambicensis, was investigated. The complete parasitic cycle of M. dubia was elucidated and found to be similar to that of M. bourguignati, as described by Fryer (1961). Host species were noted amongst the cichlid and mormyrid families, and the conclusion drawn that the species is not host specific. various aspects of the life-cycles of the other two species were noted, but complete life-cycles were not successfully elucidated. population composition according to age showed the most common species, c. mossambicensis, to be comprised mainly of 2 - 5 year-old individuals, indicating a young and vigorous population. Juvenile pre-adult mussels were very scarce. In the population of A. wahlbergi, older mussels formed a greater proportion of the biomass than in the population of c. mossambicensis, and young were also scarce. M. dubia were not recorded in sufficiently large numbers to estimate age composition accurately. The production rate (whole wet mass) of the most common species, c. mossambicensis, was calculated to be 2,45 kg ha¯¹ day¯¹ in the sanyati East cleared area (30,5 km²), while the overall production rate of all three species was calculated to be 3,34 kg ha¯¹ day¯¹. Calorific values of all three species were obtained, while gross body composition in terms of water, fat, protein, ash and amino acid composition were determined. The ash component of A. wahlbergi was analysed. The Lake Kariba results were supplemented by a follow-up study of the composition of the mussel population of a eutrophic, highveld dam, Lake McIlwaine, in 1978/1979. This much smaller lake was populated by only two mussel species, M. dubia and C. mossambicensis, although A. wahlbergi and Unio caffer were recorded in the riverine upper reaches. Observations on seasonal breeding of the two lake species were made. A detailed study on the draw down zone of a gently shelving beach showed that at the time the extreme shallows had been dominated by C. mossambicensis, whereas from a depth of approximately 1,6 m M. dubia dominated very significantly. Fulling lake level was found to trigger off migratory responses, thus placing a proportion of individuals in deeper water and improving chances of survival. The mussel composition of Lake Kariba and Lake McIlwaine was considered in conjunction with preliminary observations of mussel distribution a nd composition in other water bodies, and some inferences drawn regarding the ecological factors which appear to influence the composition and diversity of the mussel fauna in rivers and lakes.
Social ecology of Otomys irroratus, Rhabdomys pumilio and Praomys natalensis.
(1982) Willan, Kenneth Brian Ronald.; Hickman, G.; Meester, Jurgens Anthonie Jansen.
This work sets out to describe the socio-ecological niches of otonya irroratus, Rhabdomys pumilio and Praomys natalensis in the Natal midlands. This objective necessitated a broad-based approach in which aspects of the ecological niches, and the social behaviour and social organization of the three species were investigated in field (habitat and trapping) and laboratory (experimental and observational) studies, during the period January 1976-May 1978. To test the assumption that the commonly sympatric O. irroratus, R. pumilio and P. natalensis are primarily adapted to habitats which differ mainly in respect of water availability, an attempt was made to define their positions on a mesic/xeric continuum. The results suggest that in terms of the parameters measured (responses to water and cover availability, and to food and water deprivation), O. irroratus is more nearly mesically adapted than is R. pumilio, with P. natalensis positioned between the two extremes. However, in the case of P. natalensis it is apparently of overriding importance that this species is adapted to disturbed habitats. The mesic habitats preferred by O. irroratus are often of limited size, but resource availability within these areas is apparently high and stable. Extensive areas of suitable habitat are available to R. pumilio, but availability of resources is seasonally variable. The disturbed habitats preferred by P. natalensis arise unpredictably in nature and, depending on the rate of ecological succession, may be short-lived; hence availability of resources to this species is highly unpredictable. Social behaviour was studied by means of dyadic encounters in the laboratory. Communication in O. irroratus, R. pumilio and P. natalensis appears to be dominated by auditory, visual and olfactory signals respectively, although O. irroratus also has well developed visual signals in its communicatory repertoire. These differences are explained mainly in terms of patterns of diel activity and habitat preferences: R. pumilio is adapted to bright light, and its visual signals are subtle; O. irroratus is adapted to dim light, and its visual signals involve gross changes in posture, while the use of loud, low frequency vocalizations would allow conspecifics to know their precise location in relation to one another in dense vegetation; P. natalensis is nocturnal, and hence appears to emphasize olfactory (and possibly ultrasonic) communication, which would permit transfer of information in the dark. O. irroratus is overtly highly aggressive, but agonism is ritualized; ritualization of aggression has probably evolved to allow high densities of this species to exploit limited areas of prime habitat. R. pumilio is less overtly aggressive than O. irroratus, but aggression tends to be unritualized; direct aggression probably acts as a spacing mechanism, and is possible in view of the large areas of habitat available to this species. Agonism is poorly developed and ritualized in P. natalensis, permitting high sociability and group formation in this species, and maximum exploitation of locally abundant resources. Social organization was studied in the field (trapping studies) and by means of dyadic encounters in the laboratory. The social system of O. irroratus appears to include temporal territoriality, which would permit animals to live in close spatial association (in small areas of habitat) while seldom actually meeting. Hierarchical ranking occurs in male O. irroratus and R. pumilio, with competition in both most likely being for mating opportunities. Breeding females of these two species are intrasexually territorial, in the case of Q. irroratus thereby providing dispersing young with adequate space for establishment of a home-range in prime habitat, and in R. pumilio protecting the young against conspecific female aggression until dispersal. R. pumilio tends to aggregate in mesic refuge habitats in winter, which apparently reflects the seasonality of resource availability to this species in drier environments. P. natalensis is colonial, an adaptation facilitating maximum exploitation of temporarily abundant resources in transitory disturbed habitats. In response to intense courtship by the male, female R. pumilio appear to undergo reflex ovulation; this strategy would maximize the chances of fertilization occurring during occasional meetings between males and females. Courtship intensity is low in P. natalensis, and presumably because the colonial social system of this species ensures frequent association between potential mates, females appear to ovulate spontaneously. Sexual activity was not observed in O. irroratus. The life-history tactics of the three species are such that o. irroratus and P. natalensis respectively appear to be K- and r-selected, with R. pumilio falling between these two extremes on an r-K continuum.
A study of the blackshouldered kite Elanus caeruleus.
(1982) Mendelsohn, John Martin.; Maclean, Gordon Lindsay.
No abstract available.
A revision of the genus Ancilla Lamarck, 1799 (Mollusca : Olividae : Ancillinae)
(1982) Kilburn, Richard Neil.; Heeg, Jan.
The genus Ancilla Lamarck, 1799, contains 34 valid species and subspecies; 41 names previously applied to the group are reduced to 23, and 11 new species described (Kilburn, 1977, 1980, 1981). A provisional subgeneric classification is proposed. Subgenus Hesperancilla Kilburn, 1981, is established for the Brazilian A. matthewsi Burch & Burch, 1967, and Javancilla Kilburn, 1981, for the Eocene A. boettgeri Martin, 1914. Inadequate data on its type species prevents definition of subgenus. Ancilla s.s. at this stage, but Recent Indo-Pacific taxa are provisionally divided into (a) subgenus Sparellina P. Fischer, 1883, with an autapomorphic pectinate rachidian and (b) subgenera sparella Gray, 1857, and Chilotygma H. &. A. , Adams, 1853, with synplesiomorphic tricuspidate rachidians. The phylogeny and biogeography of the genus are discussed. The subfamily Ancillinae is reclassified, and a tentative cladogram proposed.
Growth and reproduction in the fruit bat Epomophorus wahlbergi.
(1983) Sowler, Sandra Georgina.; Hanks, John.
This study was carried out on the Natal South Coast between 30° 12' S and 30° 19' S, where 1085 Epomophorous wahlbergii were caught by mist-netting, and a captive breeding colony was kept between June 1977 and February 1982. Age determination techniques were developed using three criteria; linear growth measurements to obtain the age of animals prior to the attainment of the growth asymptote, tooth eruption to determine the age of animals prior to the attainment of a full permanent dentition, and tooth wear in combination with birth-pulse timing to obtain the age of animals after the growth asymptote and full permanent dentition had been reached. Stevens asymptotic growth curve, performed on forearm length, eye-nose distance and zygomatic width, observations of tooth eruption in cage born bats and linear regression of tooth height data provided the basis for age predictions. Age structure of the population indicated that the greatest percentage of losses occurred between the 5-10 and 10-15 month age group in both sexes. A maximum ecological longevity of nine years is suggested. A killed sample of 81 males and one live caged male provided the basis for the male reproductive study. Puberty onset occurred at eight months and sexual maturity attainment at 13-17 months. Sperm was present throughout the year and no seasonal variations in testicular or gonadial parameters occurred. However, seasonality was shown in body mass, blood testosterone levels, epaulette hair length, calling and testes position. The unusual and constant presence of spermatocytes/spemlatids in the epididymis cauda was observed and meiotic abnormality suggested as an explanation. Epaulettes have an attractive function for females during the mating period, and calling probably acts as a means of year-round territory maintenance. Lek mating is considered possible and a seasonal change in behaviour during the mating season from male groups to individual callers may occur. Five hundred and fifty three captured and released females and a killed sample of 111 females provided the basis for the female reproductive investigation. Puberty commenced at 2,5 months and sexual maturity was attained at six months. The first proestrus onset took place at a mean age of 5,6 months and first conception at 6,2 months. The species exhibits a seasonally polyoestrous pattern with an extended season. Conceptions occur from May to December, the peak months being May, June and July. Births occur from October to June with the peak birth season in November and December. The majority of females undergo one pregnancy per year terminating in November/December with a small percentage terminating around April. Primordial, primary, secondary and early vesicular follicles were present in the ovary year round. The presence of intermediate and late vesicular follicles however followed a seasonal pattern covering April to November. Increased uterine epithelial height and endometrial gland numbers followed a bimodal pattern. Oestrus can occur in the absence of a male and conception peaks coincided with shortest daylength, lowest rainfall, temperature and humidity. Fruiting and rainfall are suggested as ultimate causes of breeding as the peak in lactation coincided with rainfall and fruiting maxima. A series of timetables showing variations in the timing of the annual reproductive cycle with one and two pregnancies is presented. A precaution against abortion and preparation for a postpartum pregnancy were used to explain the presence of intermediate and late vesicular follicles in the non-luteal ovary at the beginning and end of pregnancy. Ovaries and uterine horns showed a functional dextral dominance although anatomically left and right appear symmetrical. Alternation of ovarian function between left and right may occur in those animals undergoing two annual pregnancies. A localized endometrial reaction may occur but was not confirmed. No transovular migration takes place. The corpus luteum reached maximum size at the beginning of pregnancy and was absent at the end. E. wahlbergi was found not to fit into the usual pattern of autumn conceptions and spring births. The species showed a high fecundity rate for a monotocous species and the gestation period was long for its body size. Parturition, lactation, maternal care and juvenile behaviour were observed in the captive colony. A method for inducing birth, using Prostaglandin E(2) and Oxytocin was applied. Births took place during daylight hours. The labour posture was head down and delivery occurred after three hours of labour. Fetal presentation was head first and placental delivery was delayed until approximately two hours after birth. Placentophagia was observed. The infant is born dorsally furred, with eyes closed and large muzzle, weighing up to 20,3 % of the mother's postpartum mass. Mother/infant behaviour and juvenile behaviour up to flight initiation is described. Competent flight takes place at a mean age of 81,1 days. Milk is higher in carbohydrate content and lower in protein content than previously studied insectivorous bat milk. A correlation is suggested between head first delivery presentation, delay in placental delivery, appearance of the infant at birth and those species which carry their young in flight instead of leaving than behind in a nursery.
An integrated approach to the management of common reedbuck on farmland in Natal.
(1983) Howard, Peter Charles.; Hanks, John.; Collinson, Roger.; Grimsdell, Jeremy.; Rowe-Rowe, David Treloar.
This study was motivated by the Natal Parks Board which has been receiving a growing number of complaints from farmers concerning reedbuck grazing of commercial crops. The reedbuck is an important conservation species, which has recently disappeared from 80 % of its previous range in South Africa, and has become extinct in the Cape Province and the Orange Free State. The study was intended to look objectively at the crop damage problem and conservation status of reedbuck on private land in Natal, and make recommendations for management. A postal questionnaire was used in assessing the species' present distribution in Natal, and an intensive study was undertaken in the Underberg district of the Natal highlands. The study area comprised approximately 10 500 ha of semi-intensive agricultural land, divided into 23 farm properties, and was considered representative of farmland throughout the highland and midland regions of the province, where nutritious food in the form of irrigated pasture grasses is available throughout the year. Four animal census techniques were critically evaluated, and reedbuck numbers assessed throughout the study area. The study area was divided into no-cull, low-cull and high-cull blocks, and population trend examined over two years in each. Population stability was demonstrated in all blocks. Post mortem examination of nearly 200 reedbuck showed that the animals were in excellent physiological condition throughout the year, and the population appeared to be at, or close to its genetic potential as regards productivity. A 20 % annual 'surplus' of animals appeared to be produced. Eighty four reedbock were marked, and resightings of some of these far from their place of capture confirmed that emigration of young animals is an important population regulatory process. A multiple regression analysis of reedbuck-habitat relations, based on observed reedbuck numbers on the 23 farm properties, demonstrated that population size appeared to be llinited by the availability of cover. An examination of social organisation and behaviour led to the belief that cover is limiting because it is a resource that is monopolised by dominant territorial males at the time when females are attracted to it to give birth. Within two months these females, nursing their newborn lambs, become oestrous again, and are mated by the territorial males. Because of the relatively low densities at which stability is achieved, crop damage only becomes a problem in exceptional circumstances. A best estimate of 0,2 t of pasture grass lost per reedbuck per winter was made.

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