Summary This paper investigates, through experiments using surrogate predators, differences in intraspecific alarm calls between familiar and unfamiliar Bronze Mannikin Spermestes cucculatus groups. Four groups of mannikins were captured with mist nets from four areas in Durban (i.e. original groups) and randomly mixed (i.e. assorted groups). These groups were exposed to latex terrestrial snakes and mounted aerial raptors, and their alarm calls and predator response behaviours recorded. The Bronze Mannikins were able to discriminate between predators of different sizes, and increased their calling rate and decreased the end frequency of the alarm call in response to larger predators. This perhaps signalled increased threat, while simultaneously decreasing the conspicuousness of the flock. When the alarm call structure of the original and assorted groups in response to both raptors and snakes was compared, birds in original groups called more often, but paused longer between calls. Anti-predator behaviour differed in that assorted groups were less vigilant and aggressive toward the predators and panicked more frequently. In these groups, a failure to transfer the predation threat information might have caused the group to stop behaving cohesively and reliably. The manipulated experiments carried out in this study indicated that Bronze Mannikins were able to communicate predator size risk to conspecifics, but not as successfully to unfamiliar group members, showing that the investment, probability through altruistic payback, is greater in stable groups.

The growing implementation of ergonomics in the automotive sector sets high demands on Digital Human Modelling (DHM) functionalities towards the simulation of more realistic environments and the reduction of physical model dependency. During the current degree project a leading element that smartly assembles DHM usage (implementation of high-level commanding languages) was designed, revolving around the industries’ needs which were gathered and interpreted in order to organize current functions in this language and suggest new complementary functions that would create a language environment suitable for non-expert users. This was achieved by focusing in an intuitive word-function structure, the proposal of defaults and other tools that aid users with different kinds of expertise. The need for realism of simulations was assessed by the language design especially by designing means to coordinate synchronic manikin-actions. / Virtual Driver