[Grazing as a conditioning factor of the population dynamics of the red partridge (Alectoris rufa) [Portugal]]
1997
Santos, P.A. | Ramalho, M. | Sequeira, R.
After a briefing of the present state of art, based in the available bibliography and opinions of farmers and game experts, the first results of the field work carried out by the authors are presented. During the field work the reproductive stock and the breeding success of the red-legged partridge (Alectoris rufa) were estimated in several farms with different livestock densities, in order to evaluate the impact of the livestock grazing on the population dynamics of the species. The results obtained and presented in this paper suggest that heavy densities of livestock affects negatively that dynamics, either directly by the perturbation of the nesting birds, or indirectly by the loss of habitat suitability: loss of food resources and loss in quantity and quality of nesting cover. The density of the breeding stock in Spring and the breeding success were lower in the areas heavily grazed. Finally a few measures are proposed in order to improve the reproduction conditions in farms with grazing livestock, namely the implementation of a rotational grazing system in such a way that some areas are not grazed during the period of pair formation and nidification and also the creation of areas not grazed in the corners of the grazing fields by means of fencing those corners
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