Abstract: Abstract
Aggregate estimates for wildlife populations and species diversity on private land in Namibia
were made for 1972 and 1992, using questionnaire surveys. Numbers of species and biomass
appear to have increased by some 80 percent, or three percent per annum over the period. The
number of game species recorded increased by 44 percent. Cost – benefit analysis models were
developed and used to analyse economic and financial efficiency of land use involving wildlife
on private land. Financial profitability was generally low with both livestock – game production
for consumptive use and wildlife production for non-consumptive use. However these activities
appear to be economically efficient, and result in a positive contribution to National Income.
The results suggest that there are financial incentives for private landholders to group together
and form large scale conservancies. The latter benefit from economies of scale which make them
more financially profitable and robust, and also more economically efficient, than ranches.
Wildlife production for non-consumptive wildlife viewing was found to yield greater economic
net value added per unit of land than livestock – wildlife production for consumptive use. This
was particularly the case at the larger conservancy scale of operation. Aggregate estimates, in
1994 prices, of the annual net value added to National Income from wildlife use on private land
are N$ 30.6 million in 1972 and N$ 56 million in 1992. The economic value of wildlife use as a
proportion of the economic value of all private land rangeland uses appears to have risen from
five percent to eleven percent over the twenty year period. Current policy to promote the
development of wildlife conservancies appears to be economically sound, particularly where
these are aimed at eventual conversion to wildlife-based tourism uses.
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Abstract: Father-daughter matings and its avoidance mechanism were analysed on the basis of data which gained from behavioural observations and paternity tests in Misaki feral horses from 1979 to 1994. Twelve stallions and their 51 daughters had 176 breeding seasons, but they lived in the different home range in 82 breeding seasons. About half of 1- to 3-year-old mares emigrated from natal area to the other and grew up there. Therefore, emigrations of young mares may result reduction of contacts and avoidance of inbreeding with their fathers. The stallions and their daughters lived in the same area in 94 breeding seasons, but there were no cases that daughters which left their natal harem groups before sexual maturity formed again stable consort relations with their natal harem stallions. It is possible that separation of young mares from their natal groups before sexual maturity may result avoidance of formation of consort relation with their fathers. Two father-daughter matings were observed in 124 paternity tests. These two daughters were born in the other harem groups than their father's and left their natal groups before maturity. After maturity, one of them formed a stable consort relation with her father and the other remained together with her father for 2 months in the breeding season. Both of them had not experience to have lived with their fathers before maturity. The persent result supports the hypothesis in wild and semi-wild horses that inbreedings between fathers and daughters may be avioded by the experience to have lived together before sexual maturity.

Abstract: Social, genetic and reproductive consequences of natal dispersal were investigated in female horses,Equus caballus, living in a herd with a natural social structure. Dispersal did not as a rule reduce the level of competition the young mares faced: they did not selectively join groups with fewer resident females than the groups they left, and they did not attain higher ranks; there was also no tendency for females to disperse to groups with the fewest resident females, and they suffered more aggression from the mares in their new groups than in their natal groups. These results therefore do not support the hypothesis that a function of natal dispersal is to reduce intra-sexual competition. The young mares nevertheless dispersed non-randomly, generally joining harems with one stallion and at least two subadult females; and they preferred to move to groups with familiar females but no familiar males. As a result, most were closely related to some females of their new groups, but distantly related or unrelated to the male(s). Since after dispersal the young mares bred only with a male of their new groups, inbreeding coefficients of most (85%) of their offspring were lower than from matings between half siblings. These results are consistent with the hypothesis that a function of natal dispersal is to avoid close inbreeding. Dispersal did not appear to involve reproductive costs: the young mares suffered no delay in age at first reproduction, and the survival rates of their first foals tended to be higher if the females had emigrated, although not significantly so.

Abstract: Abstract  Natural conceptual discriminations have been tested in many different species, including pigeons and a variety of non-human primates. The ability of four male squirrel monkeys (Saimiri sciureus) to learn and use the natural concept “squirrel monkey” was investigated in this study. After a training phase, subjects were presented with novel stimuli in transfer and test trials. All subjects performed at a rate significantly above chance on the first test trial (p<.001), indicating that squirrel monkeys can utilize natural concepts in the laboratory.