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Grouping patterns within the genus Tragelaphus suggest that species inhabiting open areas tend to live in larger groups, while species preferring dense habitats live solitarily or in small family groups. We asked if similar variation would be concealed in the within-species variation of bushbuck ( Tragelaphus scriptus). Recent molecular phylogeographic analyses revealed several locally adapted forms of bushbuck in different ecoregions on the African continent. We compared group sizes of south-eastern bushbuck ( Tragelaphus sylvaticus) among six different populations (“ecotypes”). To date, most data on the social organization of bushbuck have been collected from only one population in Queen Elizabeth National Park (QENP) in Uganda. This particular population, however, inhabits an unusual—comparatively open—habitat type, while bushbuck otherwise inhabit dense habitats, leaving doubt whether data collected in QENP are representative of the entire species. We, therefore, compared grouping patterns between ecotypes inhabiting rather open habitats (e.g., dianae and haywoodi) and ecotypes occupying rather dense habitats (e.g., massaicus and ornatus). In bachelor groups and in all-female (spinster) groups, single sightings were the most frequent “group type” in all populations examined. We detected no significant difference among ecotypes in relative frequencies of group size categories in the case of bachelor groups. Spinster group sizes were slightly (albeit significantly) smaller in QENP than in all other areas. Moreover, a comparison of two areas inside (low human pursuit) and outside Lake Mburo National Park (high hunting pressure) in Uganda revealed no significant difference in grouping patterns in response to human pursuit (as reported for impala [ Aepyceros melampus] inhabiting the same area). Altogether, our results suggest that group sizes in bushbuck are not dependent on the habitat type they inhabit; neither does human nuisance have an impact on grouping patterns. Hence, an “almost solitary” lifestyle appears to be a characteristic of the entire taxon. [ABSTRACT FROM AUTHOR]

It has been suggested that all species of spiral-horned antelopes (Tragelaphini) lack territoriality. Furthermore, some authors suggested that bushbuck ( Tragelpahus scriptus) males form dominance hierarchies. In this study, we investigated the dominance relationships in two groups of free-ranging bushbuck males in Queen Elizabeth National Park, Uganda. Adult males dominated young-adult bachelors and subadult males, but no distinct dominance relationships were found among adult males. Landau′s index of linearity revealed no linear dominance hierarchy in the study populations. Our results support the idea that adult males are territorial, and overt aggression is directed almost exclusively towards bachelors that challenge territory holders. [ABSTRACT FROM AUTHOR]

A free-ranging bushbuck ( Tragelaphus scriptus) population was observed over a period of 3 years, thereby enabling long-term observations on object-horning behaviour (“horn-rubbing”, “ground-horning” and “horn-thrashing”) in male bushbuck. The primary aim of this study was to determine whether object-horning in male bushbuck serves as demarcation of a territory. Of the three male age classes investigated (territorial males, young-adult bachelors, sub-adult males) adult, territorial males tended to perform object-horning significantly more often than the members of the other two age classes. An analysis of whether territorial males performed object-horning more often in the presence of another individual, which would suggest that object-horning acts as a visual display, revealed that object-horning was predominantly performed when males were solitary. These results suggest that scent-marking and/or leaving visible traces on the vegetation or on the ground plays an important role in territory demarcation. No correlation was detected between food plant preferences and the frequency at which plant species were used for marking. [ABSTRACT FROM AUTHOR]

We investigated mating tactics in three social/age classes of male bushbuck (Tragelaphus scriptus), i.e., adult territorial males (>5 years), young-adult non-territorial males (3-5 years) and subadult males (1-3 years). Territorial males were found to associate more frequently with females than subadult males, but young-adult males did not significantly differ from territorial males. In all three classes of males, the spatial distribution of the males relative to that of the females (i.e., their home range overlap) predicted the rate of association between males and females (Cole's coefficient of association). Territorial males showed very high rates of premating behaviour compared with the other two social/age classes and frequently attempted to monopolise females; however, copulation rates did not significantly differ between adult territorial and young-adult non-territorial males. Agonistic behaviour was most frequently initiated by territorial males when approached by a young-adult male, whereas aggressive interactions between two territorial males were far less frequent. Our results indicate that two age-dependent mating tactics exist in male bushbuck, that of adult territorial males and a sneak-like tactic in young-adult males. Nevertheless, territorial males may have an advantage over non-territorial males, because they have more unhampered opportunities to monitor females via deposited excreta in localised defecation sites. [ABSTRACT FROM AUTHOR]

A free-ranging bushbuck ( Tragelaphus scriptus) population was observed over a period of 3 years, thereby enabling a detailed description of the behavioural repertoire of this widespread but barely investigated solitary African antelope species. Agonistic and submissive behaviour patterns are described, among them several hitherto un-described behaviour patterns—such as “escorting”, where territorial males guide intruders to the periphery of their territory—and “push-up position”, an extreme form of submissive behaviour. Furthermore, we report on behaviour patterns of males and females during mating as well as on behaviour patterns of parents directed towards their offspring. Again, we describe a hitherto unknown behaviour: the protection of calves by adult males, which may be a socio-positive behaviour directed towards their offspring led by kin selection. [ABSTRACT FROM AUTHOR]

Like several other mammals, bushbuck ( Tragelaphus scriptus) deposit faeces in specific localised defecation sites (LDS). A previous study has ruled out a function of LDS in the context of parasite avoidance. In this study, we investigated the communicatory significance of LDS. In a free ranging population, we tested whether LDS serve to demarcate home ranges, and/or if LDS are used for communication in a non-territorial context. In both sexes, LDS increased significantly in number towards the periphery of individual home ranges. However, the distribution pattern of LDS, as revealed by a nearest-neighbour mapping technique (nearest distances between LDS), did not support the idea that LDS serve home range/territory-demarcation because LDS did not follow a pattern of minimal nearest-neighbour distances along the margins of home ranges. We found females to urinate more often in LDS than males. Notably, information transfer was most frequent between sending (urinating or defecating) females and receiving/responding males (urination or defecation at places where a female had previously signalled). Our results suggest that LDS mainly serve for inter-sexual communication in bushbuck. [ABSTRACT FROM AUTHOR]

In matrilineal species, females and their offspring are organised within a group along lines of female kinship, i.e. matrilines or natal breeding groups. In some gregarious artiodactyles, daughters remain associated with their mothers into adulthood. To test this on a solitary living artiodactyle, the bushbuck ( Tragelaphus scriptus), home-range overlap, social vicinity and differentiated social relations between related and non-related females were used as indicators for the existence of matrilineal structures. Results of numerical classification and matrix correlation of social and spatial vicinity were matched with known kin relations indicating the existence of natal breeding groups among females. An extended home-range overlap between kin suggested restricted movements of females and therefore a female residence or philopatry. Differentiated and consistent female relationships signified matrilineal structures and suggested a competitive regime between female clans. We therefore conclude that complex kinship structures also exist in non-gregarious ungulate species. [ABSTRACT FROM AUTHOR]