A biochemical genetic study of Gyps coprotheres with notes on the bioaccumulation of pesticides in the blood

M.Sc. (Zoology)Blood samples were obtained from 42 Cape (Gyps coprotheres) Vultures during the period 1990 to 1991. Nestlings were sampled at two natural localities namely the Scheerpoort and Manoutsa colonies. Samples from captive birds ranging in age from immature to mature were obtained from four locations which include the Johannesburg Zoo, Tygerberg Zoo, De Wildt Cheetah Research and Breeding Station and World of Birds. The main objective of the study was to describe the population genetic structure of G. coprotheres by means of a protein electrophoretic examination. The optimum electrophoretic conditions were determined for maximum resolution of the protein systems examined. Allele frequency data assessed at 34 structural gene loci were obtained. As measures of variability, the perc~ntage polymorphic loci and average heterozygosity were calculated for the Cape vulture and values obtained were 11.76\ and 0.021 respectively. Both of the latter values are less than half the values reported for the majority of other avian species. The electrophoretic data were utilised in two population genetic simulation programmes and it was determined that the variation present in the populations of G. coprotheres studied may disappear within the next 35 generations. The blood samples were also subjected to a toxicological examination. Concentrations of DDT and its derivatives were measured by gaschromatographic analyses. Biocide levels were detected in ppb and adjusted to ppm by a conversion factor of 150. Quantifiable levels of DDT, DOD and DOE were detected in 72.4\, 60.0% and 89.7% of the individuals respectively. DOE is one of the major metabolites of DDT and the discussion was focused on levels thereof