Un facteur de mortalité mal connu, l’asphyxie par gaz toxiques naturels au parc national Albert, Congo

Résumé En

The numerous instances of the destruction by volcanic gases of large numbers of mammals, birds, reptiles, amphibia and insects in the Albert National Park in the Congo are reviewed by the author on the basis of observations made by him between 1957 and 1961. Such asphyxiations occur at definite places which are known by the vernacular name of «masukus», meaning places of gas discharge, and the characteristics of these areas and the lists of dead animals found in them are given. The gas responsible for the killings is carbon dioxide ; and the fact that the discharge is not continuous increases the effectiveness of these «natural gas chambers» as animals would soon learn to avoid a place of continuous discharge. Experiments carried out with domestic animals show that immobilization occurs with great rapidity, and that these CO2 pockets are lethal even to birds and bats which fly into them. The «masukus» are not completely sterile as some plants manage to thrive in them. They have undoubtedly played a role in the building up of some fossil deposits, and it is interesting to speculate that they may well account for the legend of «elephant cemeteries» which persists in so many parts of Africa.