Browsing by Author "David, Jeremy Hugh Markham"

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    The behaviour of the bontebok Damaliscus Dorcas Dorcas, with special reference to territorial behaviour
    (1970) David, Jeremy Hugh Markham; Broekhuysen, G J
    Fieldwork for this study was commenced during the end of January 1969 and terminated in mid-April. 1970. It was conducted on a full time basis and follow-up visits were made to the Park at intervals duririg the remainder of 1970. The study was carried on exclusively in the Bontebok National Park which contains by far the largest herd of bontebok in the country. Visibility in the Park is good and all observations were made from a vehicle with the aid of binoculars at distances ranging from about 30 m to over 400 m. Most animals were tolerant of a motor vehicle but there were one or two exceptions, particularly territorial males whose territories were situated away from the roads and who were therefore unused to being approached closely by vehicles. Females were on the whole more nervous than males and especially females with new born lambs were very nervous and would run from a vehicle at 100 m or more.
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    Demography and population dynamics of the striped fieldmouse, Rhabdomys pumilio, in alien Acacia vegetation on the Cape Flats, Cape Province, South Africa
    (1980) David, Jeremy Hugh Markham; Jarvis, J U M
    In view of the fact that the long-term study of small mammal populations in southern Africa has been largely neglected, this project was an attempt to document more accurately than has hitherto been the case in Africa, the population changes in a small rodent, the striped fieldmouse, Rhabdomys pumilio, over a relatively long period of time. It was felt that the usual field study of one or two years duration was insufficient to obtain reliable data on demographic parameters. This was because it was important to document the variability of population data and to have as large sample sizes as possible. The fieldmouse is an omnivore but mainly granivorous and the habitat chosen was favourable for the mice, being dominated by thickets of alien Acacia cyclops and A. saligna, which provided abundant food (seeds) all year round, as well as cover and shade. The study was conducted on the Cape Flats, an area of lowlying sand dunes, on the banks of the Kuils River. Livetrapping grids were established, consisting of parallel rows of trap stations, 10m apart. The overall size of the study area was 2,55ha with a total of 156 stations. This comprised a central control grid of 60 stations (0,45ha), which was first trapped in April 1972 and where regular monthly trapping for 4 consecutive days and nights was conducted from July 1972 through May 1977. This was surrounded on three sides by peripheral grid K of 96 stations arranged in three parallel rows (see Fig. 2). Trapping was conducted in 324. grid K from February 1975 through February 1976 in an attempt to detect dispersal of mice from the control grid. From March 1976 through May 1977 trapping was conducted in a third grid, experimental grid E, which was established in the north side of the old grid K. It comprised 60 stations (0,44ha), in which supplementary food was supplied in the form of commercial rat pellets. The effects of the extra food on the population of mice were compared with the control grid. The mice were readily captured in box-type aluminium Sherman livetraps and all mice caught were marked by toeclipping and released. A total of 2281 R. pumilio were marked and released during the five year study. In addition, over 860 specimens of R. pumilio were killtrapped for autopsy in the laboratory. These yielded information on reproduction, food habits and morphological characteristics - particularly skulls for age determination by tooth wear.