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In a synthetic approach to studying navigational abilities in desert ants, we review recent work comparing ants living in different visual ecologies. Those living in a visually rich habitat strewn with tussocks, bushes, and trees are compared to those living in visually barren salt pans, as exemplified by the Central Australian Melophorus bagoti and the North African Cataglyphis fortis, respectively. In bare habitats the navigator must rely primarily on path integration, keeping track of the distance and direction in which it has travelled, while in visually rich habitats the navigator can rely more on guidance by the visual panorama. Consistent with these expectations, C. fortis performs better than M. bagoti on various measures of precision at path integration. In contrast, M. bagoti learned a visually based associative task better than C. fortis, the latter generally failing at the task. Both these ants, however, exhibit a similar pattern of systematic search as a 'back up' strategy when other navigational strategies fail. A newly investigated salt-pan species of Melophorus (as yet unnamed) resembles C. fortis more, and its congener M. bagoti less, in its path integration. The synthetic approach would benefit from comparing more species chosen to address evolutionary questions. This article is part of a Special Issue entitled: CO3 2013.

Starting from homogenous highly packed green bodies, two sintering methods have been combined in order to limit grain growth during the densification of fully stabilized zirconia. Densification behavior and microstructures in relation with green body shaping have been investigated. It could be shown that two step sintering schedules carried out by FAST/SPS are very effective in reducing both processing time and grain growth.

The Australian desert ant Melophorus bagoti shows remarkable visual navigational skills relying on visual rather than on chemical cues during their foraging trips. M. bagoti ants travel individually through a visually cluttered environment guided by landmarks as well as by path integration. An examination of their visual system is hence of special interest and we address this here. Workers exhibit distinct size polymorphism and their eye and ocelli size increases with head size. The ants possess typical apposition eyes with about 420–590 ommatidia per eye, a horizontal visual field of approximately 150° and facet lens diameters between 8 and 19 μm, depending on body size, with frontal facets being largest. The average interommatidial angle Δϕ is 3.7°, the average acceptance angle of the rhabdom Δρrh is 2.9°, with average rhabdom diameter of 1.6 μm and the average lens blur at half-width Δρl is 2.3°. With a Δρrh/Δϕ ratio of much less than 2, the eyes undersample the visual scene but provide high contrast, and surprising detail of the landmark panorama that has been shown to be used for navigation.