Ecology,feeding competition and social structure in baboons

Predictions of the model of van Schaik (1989) of female-bonding in primates are tested by systematically comparing the ecology, level of within-group contest competition for food (WGC), and patterns of social behaviour found in two contrasting baboon populations. Significant differences were found in food distribution (percentage of the diet from clumped sources), feeding supplant rates and grooming patterns. In accord with the model, the tendencies of females to affiliate and form coalitions with one another, and to be philopatric, were strongest where ecological conditions promoted WGC. Group fission in the population with strong WGC was “horizontal” with respect to female dominance rank, and associated with female-female aggression during a period of elevated feeding competition. In contrast, where WGC was low, females’ grooming was focused on adult males rather than other females. Recent evidence suggests that group fission here is initiated by males, tends to result in the formation of one-male groups, and is not related to feeding competition but to male-male competition for mates. An ecological model of baboon social structure is presented which incorporates the effects of female-female competition, male-male competition, and predation pressure. The model potentially accounts for wide variability in group size, group structure and social relationships within the genus Papio. Socio-ecological convergence between common baboons and hamadryas baboons, however, may be limited in some respects by phylogenetic inertia. Received: 22 April 1994/Accepted after revision: 9 December 1995     

Eco-neighbourhoods: A review of projects

The recent literature on sustainable urban form has stressed the need to move away from a system of land-use segregation and towards one which intersperses land uses and facilitates localisation. The strategy of dispersed concentration gives shape to this mixed-use principle, and has been equated with the need to plan more self-sufficient neighbourhoods. There are several problematic issues raised by such a strategy, particularly in relation to the propensity of local people to use local facilities when the friction of distance is low. The image of sustainable neighbourhoods purveyed by advocates is at odds with the reality of suburban development. A review of current eco-neighbourhood projects around the world points to the varying degrees to which they have successfully overcome the implementational and behavioural difficulties. Market-led projects — particularly in semi-rural areas — have achieved rather limited success across the range of sustainability criteria. Some large-scale municipally led plans have faired better. Projects led by community non-profit trusts have been able to be most radical and demonstrate the practicability of eco-neighbourhoods in specific situations. Overall, however, the paucity of successful projects highlights the need for a more proactive central and local government stance.     

Sources and levels of potentially toxic elements in the biodegradable fraction of autoclaved non-segregated household waste and its compost/digestate

Waste that reflected the average UK composition of household waste was treated by autoclaving at the three set pressure/temperature levels of 2.7 bar/130 degrees C, 6.2 bar/160 degrees C and 15.5 bar/200 degrees C. The biodegradable fraction of the autoclaved household waste (;floc') was manually separated by screening and underwent characterization for its Cd, Cr, Cu, Pb, Hg, Ni, and Zn content. Autoclaving did not guarantee the production of compost/digestate that met the UK specification for compost, BSi PAS100, without restrictions being made on the composition of the waste feedstock. Results indicate that the levels of Zn and Cd associated with floc materials alone could lead to compost limit values being exceeded. For all other potentially toxic elements (PTEs), the estimated excessive (i.e. above levels of compliance) PTEs levels for compost/digestate were mainly due to external (i.e. non-floc) materials, primarily electronic/electrical waste. Batteries may have also contributed to the high levels of Zn and Hg. In this study, for all PTEs examined, with the exception of Cd and Zn, autoclaving had a performance comparable to that of the most effective mechanical biological treatment systems.