Mj. Samways et K. Kreuzinger, Vegetation, ungulate and grasshopper interactions inside vs. outside an African savanna game park, BIODIVERS C, 10(11), 2001, pp. 1963-1981
The human impact on the African savanna is parcelling large native mammals
into game reserves, with cattle and other livestock replacing these native
mammals in the matrix surrounding these reserves. Concordant with this are
other landscape changes such as fire maintenance within the reserve but no
longer outside. How does this composite landscape change affect biodiversit
y, as represented by small animals such as grasshoppers? This question was
addressed against the premise that grasshoppers have evolved in the context
of native mammal ecology. One of the most significant aspects of this ecol
ogy is grazing and trampling by the large number of ungulates congregating
at waterholes. The results clearly show that the grasshopper fauna is only
marginally impoverished outside the reserve, and that cattle trampling and
grazing (along with less fire) is a simulation of these impacts by native u
ngulates. As greatest grasshopper diversity is encouraged by some trampling
and grazing, the presence of cattle in place of native mammals is not enti
rely adverse to biodiversity, as represented by grasshoppers.