Influence of increasing dryness, animal feeding strategy and human hunting on large ungulates abundance: A first approach in West Africa

Abstract

Large ungulates as primary consumers consume variable proportions of herbaceous and woody plants. Recent climate changes modify the herbaceous/woody plant balance. To test their differential effects on ungulate species abundance, we compared large ungulate feeding strategies with climate change patterns, taking the game preferences of local people into account. We analyzed changes in population density of ten species of large ungulates between two census periods (1990–1993 and 1994–1998) in the Niokolo Koba National Park, Senegal. We calculated the cumulative precipitation deficit during the 1989–1997 period. Additionally, we conducted an extensive survey of local people’s game preferences. Results are: 1—in the period 1989–98 all but one year have been drier than the 1940–98 average; 2—this has a cumulative effect on the dryness of the land i.e. produces a water deficit; 3—this pattern favors the growth of woody plants over herbaceous ones; 4—this favors browsers over grazers; 5—grazers are generally preferred by hunters; 6—grazers are therefore disadvantaged both by the drier climate and by preferential hunting; 7—management in the National Park should focus on holding back bush encroachment and encouraging the growth of herbaceous plants.