Foot areas, ground reaction forces and pressures beneath the feet of kangaroos, wallabies and rat‐kangaroos (Marsupialia: Macropodoidea)

Abstract

Foot areas of a wide range of kangaroos, wallabies and rat-kangaroos were measured from fresh material and museum specimens. The areas of the plantar pads scaled according to the predictions of geometric similarity. The terminal claw areas of digits IV and V scaled with a lower than predicted exponent, re¯ecting functional demands of different species. The pressure that these marsupials exert on the ground during quiet standing is proportional to (body weight) 0.35 , and is considerably lower than those exerted by ungulates. Hopping kangaroos exert pressures proportional to (body weight) 0.37 . The pressures exerted by medium and large macropods are comparable to those of galloping ungulates. The ®ndings support the commonly held belief that introduced grazing animals may cause greater mechanical disruption of the soil surface, leading to increased rates of soil erosion, than Australia's indigenous grazing fauna.

Ungulate community structure and ecological processes: body size, hoof area and trampling in African savannas

“…His results indicated that the pressure exerted on the ground by standing sheep and goats was lower than that of oryx, eland and cattle, and he concluded that sheep and goat trampling per individual had a lower impact on the environment than that of wild ungulates. Bennett (1999) concurred and further argued that Ssemakula's data did not provide support for the generally held hypothesis that the trampling impact of domesticated ungulates was greater than that of wild ungulates. While this conclusion may be true, it was reached on spurious grounds.…”

Variability in the incidence and characteristics of animal paths in montane vegetation

“…Antelope paths were 2-3 cm deep (Boelhouwers and Scheepers 2004), shallower than the mean path depth of 3.28 cm recorded in the present study. Variation in the nature of the animal gait, the contact area and hardness of feet and hooves (Bennett 1999), the weight of the animal, the amount of traffic and differences in environment could all be responsible for the differences in path width and depth. Kobayashi et al (1997) have shown that plots trampled by humans can have a soil penetration resistance up to 10 kg cm −2 higher than untrampled plots, more than 10 times the difference recorded in the present study.…”

Human-induced changes in animal populations and distributions, and the subsequent effects on fluvial systems

“…Although the study of the geomorphic impacts of native animal species on the Australian landscape is an area of increasing interest (e.g., Bennett, 1999;Eldridge and Rath, 2002), the impacts of native species on the Australian landscape has been overshadowed by research on the impacts of non-native species (Edwards et al, 2004), including the European rabbit (Oryctolagus cuniculus L.). Feral rabbits have excavated widespread warrens across the semi-arid landscape of Australia, and in the process removed vegetation, created mounds, and compacted soils (Eldridge and Myers, 2001;Eldridge and Simpson, 2002).…”