Abstract: We investigated how plains zebras moved across a large natural landscape by analysing the movement paths of nine zebra mares foraging out from spatially confined waterholes during the dry season in the Makgadikgadi Pans National Park, Botswana. Since it was essential to investigate directed movement over a range of spatial scales to determine the correct movement behaviour and strategy, we used Nams's scaling test for oriented movement. Zebras followed directed movement paths in the lower to medium spatial scales (10 m–3.7 km) and above their visual, and possibly olfactory, range. The spatial scale of directed movement suggests that zebras had a well-defined spatial awareness and cognitive ability. Seven zebras used directed movement paths, but the remaining two followed paths not significantly different to a correlated random walk (CRW). At large spatial scales (>3 km) no distinct movement pattern could be identified and paths could not be distinguished from a CRW. Foraging strategy affected the extent of directed movement: zebras with a confined dispersion of grazing patches around the central place directed their movements over a longer distance. Zebras may extend the distance at which they can direct their movement after improving their knowledge of the local environment.

Abstract: Abstract
The evolution and origin of primate social organisation has attracted the attention of many researchers, and a solitary pattern, believed to be present in most nocturnal prosimians, has been generally considered as the most primitive system. Nocturnal prosimians are in fact mostly seen alone during their nightly activities and therefore termed “solitary foragers”, but that does not mean that they are not social. Moreover, designating their social organisation as “solitary”, implies that their way of life is uniform in all species. It has, however, emerged over the last decades that all of them exhibit not only some kind of social network but also that those networks differ among species. There is a need to classify these social networks in the same manner as with group-living (gregarious) animals if we wish to link up the different forms of primate social organisation with ecological, morphological or phylogenetic variables. In this review, we establish a basic classification based on spatial relations and sociality in order to describe and cope properly with the social organisation patterns of the different species of nocturnal prosimians and other mammals that do not forage in cohesive groups. In attempting to trace the ancestral pattern of primate social organisation, the Malagasy mouse and dwarf lemurs and the Afro-Asian bushbabies and lorises are of special interest because they are thought to approach the ancestral conditions most closely. These species have generally been believed to exhibit a dispersed harem system as their pattern of social organisation (“dispersed” means that individuals forage solitarily but exhibit a social network). Therefore, the ancestral pattern of primate social organisation was inferred to be a dispersed harem. In fact, new field data on cheirogaleids combined with a review of patterns of social organisation in strepsirhines (lemurs, bushbabies and lorises) revealed that they exhibit either dispersed multi-male systems or dispersed monogamy rather than a dispersed harem system. Therefore, the concept of a dispersed harem system as the ancestral condition of primate social organisation can no longer be supported. In combination with data on social organisation patterns in “primitive” placentals and marsupials, and in monotremes, it is in fact most probable that promiscuity is the ancestral pattern for mammalian social organisation. Subsequently, a dispersed multi-male system derived from promiscuity should be regarded as the ancestral condition for primates. We further suggest that the gregarious patterns of social organisation in Aotus and Avahi, and the dispersed form in Tarsius evolved from the gregarious patterns of diurnal primates rather than from the dispersed nocturnal type. It is consequently proposed that, in addition to Aotus and Tarsius, Avahi is also secondarily nocturnal.

Abstract: An Gitterstäben, die in der Pferdehaltung an verschiedenen Stellen verwendet werden, können sich Pferde verletzen, wenn sie ihre Köpfe oder ihre Hufe hindurchstecken und nicht zurückziehen können. Um das Verletzungsrisiko zu reduzieren sind lichte Weiten und Materialstärken von Gitterstäben so zu wählen, dass Pferdeköpfe und -hufe entweder nicht zwischen den Freiräumen hindurchpassen oder aber gefahrlos wieder zurückgezogen werden können. Die bisherige Forschung liefert jedoch keine belastbaren Aussagen zu Stababständen (senkrecht und waagerecht), die für Pferde ungefährlich sind. Die in der Praxis verwendeten und in der Literatur empfohlenen Gitterstababstände beruhen auf Erfahrungswerten und technischen Materialeigenschaften. In der vorliegenden Untersuchung wurden Pferdeköpfe und -hufe von insgesamt 480 Pferden (233 Stuten, 204 Wallache und 43 Hengste) von 23 verschiedenen Rassen vermessen, um auf Grundlage der Anatomie der Pferde Aussagen über die Eignung von marktüblichen Stababständen in der Praxis treffen zu können. Es stellte sich heraus, dass bei senkrechten Gitterstäben eine lichte Weite von nicht mehr als 5 cm für alle Pferde ab einem Stockmaß von 110 cm und einem Alter von zwei Jahren als sicher bezeichnet werden kann. Bei waagerechten Gitterstäben erwies sich eine lichte Weite von genau 17 cm als sicher. Dies gilt für alle Pferde ab einem Alter von zwei Jahren oder ab einem Stockmaß von 148 cm.
Kritisch sind die lichten Weiten von Panels zu beurteilen. Hier zeigte sich, dass die handelsüblichen Abstände der Gitterstäbe für die meisten Pferde eine erhebliche Gefahr darstellen. Wenn die Pferde beispielsweise versuchen außerhalb der Panels zu fressen und dabei ihren Kopf durch die Gitterstäbe stecken, kann es leicht passieren, dass sie sich mit dem Kopf zwischen den Gitterstäben verklemmen.
[At bars, used in various places in horse husbandry, horses can hurt themselves when retracting their heads or hooves after pushing them through the interspaces. In order to reduce the risk of injury, the clear widths and material thicknesses of bars should be chosen so that horse heads and hooves either cannot pass between the spaces or can be retracted safely. However, research to date has not provided any reliable information on bar width (vertical and horizontal) that is safe for horses. Grid bar width used in practice and recommended in the literature is based on empirical values and technical material properties. In this study, heads and hooves of 480 horses (233 mares, 204 geldings and 43 stallions) of 23 breeds were measured for making statements about the suitability of standard bar width, when considering the anatomy of the horse. It turned out that for vertical bars, an interspace of no more than five centimetres can be considered to be safe for all horses of a height of 110 centimetres and an age of two years and more. With horizontal lattice bars, a clear width of exactly 17 centimetres proved to be safe. This applies to all horses of a height of 148 centimetres and an age of two years or more. The clear widths of panels must be considered critical for horse welfare. When horses, for example, try to eat outside the panels and put their head through the bars, they may get stuck.]