RESUMEN
A study of the ecology of the bushpig (Potamochoerus porcus) showed that there were regional differences in relative investments made in reproduction and maintenance. Southern Cape populations had relatively low reproductive rates, but levels of energy storage and survival rates were high. The reverse applied to eastern Cape populations. The diets of the two populations differed, with a higher ratio of available production nutrients (NPK) to maintenance nutrients (C) in the eastern Cape. A life history model is developed which accommodates these regional differences by linking nutritional characteristics of the diet with metabolic turnover rates. According to this model, the rate of reproductive investment (number of viable young per unit of time) relative to somatic investment (energy storage, survival) is determined by the rate at which production nutrients (NPK) are procurable. For herbivorous animals this depends on the rate at which the nutrients are available to their food plants, which in turn is linked to soil fertility and thus to the geological parent material.
RESUMEN
Using gas chromatography-mass spectrometry 33 constituents of the preorbital gland of the grey duiker,Sylvicapra grimmia, were identified as unbranched alkanes, 2-alkanones, alkanals, alkanoic acids, alkan-4-olides, as well as 3-methyl-3-buten-1-ol, (Z)-9-octadecenoic acid, benzyl cyanide, diethyl sulfoxide, 2-isobutyl-1,3-thiazole, 2-isobutyl-4,5-dihydro-1,3-thiazole, and 3,4-epoxy-2-dodecanone. Determination of the relative concentrations of these components in a limited number of secretion samples taken from males and females revealed that in these samples the two thiazole derivatives and the epoxy ketone were present in consistently and significantly higher concentrations in male than in female secretions. This suggests that they could act as sex recognition cues.
RESUMEN
The identification of four further major constituents of the pedal gland exudate of the bontebok, Damaliscus dorcas dorcas, viz. alpha-terpineol, 2-n-heptylpyridine, m-cresol and (A)-6-dodecen-4-olide and the investigation of the stereochemistry of the double bond in (Z)-6-dodecen-4-olide by means of iterative computer analysis are described. An improved synthesis of this compound is outlined.