Environmental Engineering Reference
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orders of magnitude. Nevertheless, the central tendency is clear: the largest terrestrial
herbivores dominate the mammalian zoomass of their respective ecosystems (African
elephants commonly account for at least half the total), while the zoomass of the
smallest animals, dominated by rodents, will be usually less than 0.2 g/m 2 (0.2 kg/
ha), a rate coni rmed by i eld studies (Golley et al. 1975). But in suitable environ-
ments rodents can reach extraordinarily high rates: the rat zoomass on a tropical
l oodplain of the Adelaide River in Australia's Northern Territory was as high as
4.7 g/m 2 (Madsen et al. 2006).
In accounts of mammalian zoomass, it is not surprising that ecologists have paid
particular attention to the world's richest assemblages of large herbivores, in Africa's
savannas and rain forests, where the mean mass of mammals is signii cantly greater
than in Amazonia (Cristoffer and Peres 2003). Coe, Cumming, and Phillipson (1976)
compiled a list for major national parks of East, Central, and South Africa. The
highest recorded zoomass means were 19.9 g/m 2 in Uganda's Ruwenzori National
Park (calculated in the 1960s) and 19.2 g/m 2 in Tanzania's Manyara National Park.
Schaller's (1972) estimate for the entire Serengeti was 4.2 g/m 2 , similar to the
average for the southern section of South Africa's Kruger National Park, but other
published Serengeti means are up to twice as high. In two other African ecosystems
dominated by large herbivores, estimated zoomass densities range from 8.5 g/m 2
for the Simanjiro Plains of northern Tanzania (Kahuranga 1981) to 10.3 g/m 2 for
the wet-season zoomass in Kenya's Maasai Mara National Reserve (Ogutu and
Dublin 2002).
Dry-season maxima for the Ngorongoro Crater were 12 g/m 2 (Hanby et al. 1995),
while the total for all carnivores (in one the world's best habitats for large predators
to hunt ungulates) was put by Schaller (1972) at less than 0.03 g/m 2 . Large herbivore
zoomass is generally less dense in the West African parks: at Arli and Po in the
Upper Volta region it was about 1.8 g/m 2 , at Kainji in Nigeria just 1.2 g/m 2
(Milligan, Ajayi, and Hall 1982), and in Benin's Pendjari 1.1 g/m 2 (Sinsin et al.
2002). The total zoomass for all large diurnal mammals at different sites of the Lope
Reserve in Gabon was between 1 and 6 g/m2 (White 1994), and southern India's
tropical forest in the Nagarahole National Park supported 7.6 g/m 2 of wild herbi-
vores, compared to wild herbivore densities of 4.7-6.3 g/m 2 in the country's tiger
reserves (Karanth and Sunquist 1992).
Hayward, O'Brien, and Kerley (2007) tabulated average densities for all major
herbivorous species in ten of South Africa's conservation areas. Converting those
densities to biomass by using an average of 75% of adult female body mass (this
approximation accounts for the lower weights of subadults and young animals)
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