@article{WronskiApioPlath2006,
  author    = {Wronski, Torsten and Apio, Ann and Plath, Martin},
  title     = {The communicatory significance of localised defecation sites in bushbuck (Tragelaphus scriptus)},
  doi       = {10.1007/s00265-006-0174-4},
  year      = {2006},
  abstract  = {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},
  language  = {en}
}
@article{ApioMuwanikaPlathetal.2009,
  author    = {Apio, Ann and Muwanika, Vincent B. and Plath, Martin and Wronski, Torsten},
  title     = {Seasonal variation in reproductive behaviour of bushbuck (Tragelaphus scriptus Pallas, 1766) in an equatorial savannah ecosystem},
  issn      = {0141-6707},
  doi       = {10.1111/j.1365-2028.2008.01000.x},
  year      = {2009},
  abstract  = {While several authors suggest that bushbuck (Tragelaphus scriptus Pallas) from tropical areas with an approximately bimodal rainfall pattern breed throughout the year, there is also a report of seasonal breeding in this species. In this study, we provide indirect evidence of seasonality in reproduction by analysing behavioural data (e.g. rates of mixed-sex sightings) in a population of bushbuck inhabiting an equatorial savannah ecosystem in western Uganda. Observation rates of mixed-sex sightings were correlated with rainfall patterns. We suggest that peaks in reproductive behaviour following the wet season may be advantageous if calves are born during the next wet season, when fresh vegetation is available.},
  language  = {en}
}
@article{ApioPlathWronski2006,
  author    = {Apio, Ann and Plath, Martin and Wronski, Torsten},
  title     = {Patterns of gastrointestinal parasitic infections in the bushbuck Tragelaphus scriptus from the Queen Elizabeth National Park, Uganda},
  series = {Journal of helminthology},
  volume    = {80},
  journal   = {Journal of helminthology},
  number    = {3},
  publisher = {Univ. Press},
  address   = {Cambridge},
  issn      = {0022-149X},
  doi       = {10.1076/JOH2006343},
  pages     = {213 -- 218},
  year      = {2006},
  abstract  = {Seasonal, host sex and age-related variations in helminth egg and coccidian oocyst counts were investigated in a naturally infected wild bushbuck (Tragelaphus scriptus) population in Queen Elizabeth National Park, western Uganda from April 2000 to February 2002. The prevalence and mean intensity quantified as the number of eggs and oocysts per gram of faeces were taken as a measure of parasite burdens. Host sex and age-related differences in prevalence values were not found but the overall prevalence of Eimeria sp. was significantly higher during the rainy season, and peak counts were recorded either during or soon after a peak rainfall. A similar trend was observed for Moniezia spp., although the results were marginally not significant. There were also no significant differences in mean intensity values, relative to host sex, age or season.},
  language  = {en}
}
@article{ApioPlathWronski2006,
  author    = {Apio, Ann and Plath, Martin and Wronski, Torsten},
  title     = {Localised defecation sites : a tactic to avoid re-infection by gastro-intestinal tract parasites in bushbuck, Tragelaphus scriptus?},
  issn      = {0289-0771},
  doi       = {10.1007/s10164-005-0166-2},
  year      = {2006},
  abstract  = {Bushbuck (Tragelaphus scriptus) often deposit faeces at specific localised defecation sites (LDS). We tested whether LDS have a function in the context of parasite avoidance. In a population of bushbuck in Queen Elizabeth National Park, Uganda, seven radio-collared individuals were observed. We recorded feeding behaviour inside and outside LDS. Furthermore, pasture contamination with gastro-intestinal tract parasites inside and outside LDS was examined. There were significant differences between the expected and the observed feeding rates inside LDS, but, contrary to our prediction, the bushbuck increased their feeding rate inside LDS. There was no significant difference in the parasite contamination of pastures inside and outside LDS. We discuss the hypothesis that LDS mainly serve a social function in bushbuck communities, whereas parasite avoidance seems to play a minor or no role},
  language  = {en}
}
@article{AverbeckApioPlathetal.2010,
  author    = {Averbeck, Christiane and Apio, Ann and Plath, Martin and Wronski, Torsten},
  title     = {Hunting differentially affects mixed-sex and bachelor-herds in a gregarious ungulate, the impala (Aepyceros melampus: Bovidae)},
  issn      = {0141-6707},
  doi       = {10.1111/j.1365-2028.2009.01118.x},
  year      = {2010},
  abstract  = {We investigated herd-sizes and herd-compositions of Impala (Aepyceros melampus) inside a protected area [Lake Mburo National Park (LMNP) in western Uganda] and the unprotected adjacent ranchland [the Ankole Ranching Scheme (ARS)]. Impala experience intense hunting and poaching in the study area, and poaching is especially strong on the ARS. We found evidence for changes in overall group-sizes in both mixed-sex and pure bachelor herds between areas in and outside LMNP. Mixed-sex herds strongly decreased in size outside the National Park, but bachelor herds even slightly increased in size. While the group-composition of mixed-sex herds was very similar in areas in and outside LMNP, bachelor herds comprised more yearlings and subadult males on the ARS. Our study suggests that effects of hunting and other human nuisance may differ between herd types: mixed herds probably decrease in size because females are more strongly hunted. Around LMNP, impala are usually hunted using nets and spears, thereby increasing the hunters' chance of being injured. Poachers therefore prefer hornless females (and their calves), as it is less dangerous to handle net-caught females than males. As a result, males are less hunted, but increased vigilance and, therefore, reduced aggression among the members of a bachelor herd, may account for the observed increase in herd sizes and changes in group-compositions.},
  language  = {en}
}
@article{ApioKabasaKetmaieretal.2010,
  author    = {Apio, Ann and Kabasa, John David and Ketmaier, Valerio and Schroeder, Christoph and Plath, Martin and Tiedemann, Ralph},
  title     = {Female philopatry and male dispersal in a cryptic, bush-dwelling antelope : a combined molecular and behavioural approach},
  issn      = {0952-8369},
  doi       = {10.1111/j.1469-7998.2009.00654.x},
  year      = {2010},
  abstract  = {In most mammals, females are philopatric while males disperse in order to avoid inbreeding. We investigated social structure in a solitary ungulate, the bushbuck Tragelaphus sylvaticus in Queen Elizabeth National Park, Uganda by combining behavioural and molecular data. We correlated spatial and social vicinity of individual females with a relatedness score obtained from mitochondrial DNA analysis. Presumed clan members shared the same haplotype, showed more socio-positive interactions and had a common home range. Males had a higher haplotype diversity than females. All this suggests the presence of a matrilineal structure in the study population. Moreover, we tested natal dispersal distances between male and female yearlings and used control region sequences to confirm that females remain in their natal breeding areas whereas males disperse. In microsatellite analysis, males showed a higher genetic variability than females. The impoverished genetic variability of females at both molecular marker sets is consistent with a philopatric and matrilineal structure, while the higher degree of genetic variability of males is congruent with a higher dispersal rate expected in this sex. Evidence even for male long-distance dispersal is brought about by one male carrying a haplotype of a different subspecies, previously not described to occur in this area.},
  language  = {en}
}
@article{AverbeckApioPlathetal.2009,
  author    = {Averbeck, Christiane and Apio, Ann and Plath, Martin and Wronski, Torsten},
  title     = {Environmental parameters and anthropogenic effects predicting the spatial distribution of wild ungulates in the Akagera savannah ecosystem},
  issn      = {0141-6707},
  doi       = {10.1111/j.1365-2028.2009.01076.x},
  year      = {2009},
  abstract  = {Savannah areas affected by human activities such as livestock keeping and agriculture are often characterized by shifts in landscape structuring, with a predominance of few(er) habitat types. This is typically accompanied by pronounced changes in the communities of ungulates. The aim of this study was to find out whether shifts in ungulate communities in Lake Mburo National Park (LMNP) are primarily predicted by an alteration in the composition of the preferred habitat types or if more complex interactions between habitat changes and the prevalence of ungulates occur. Monthly road counts were used to establish the number of eleven ungulate species in LMNP and adjacent unprotected Ankole Ranching Scheme. The common duiker (Sylvicapra grimmia campbelliae Gray, 1843) was found in more abundance in disturbed areas, while showing a significant change in habitat use. Common duiker tended to use the vegetation type otherwise used by the bushbuck (Tragelaphus scriptus dama Neumann, 1902). Our results support the claim that the occurrence of ungulates is not only directly affected by the availability of 'suitable' habitats, but behavioural plasticity and competitive exclusion also need to be considered.},
  language  = {en}
}
@article{WronskiApioPlathetal.2009,
  author    = {Wronski, Torsten and Apio, Ann and Plath, Martin and Averbeck, Christiane},
  title     = {Do ecotypes of bushbuck differ in grouping patterns?},
  issn      = {0873-9749},
  doi       = {10.1007/s10211-009-0058-5},
  year      = {2009},
  abstract  = {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.},
  language  = {en}
}
@article{WronskiTiedemannApioetal.2006,
  author    = {Wronski, Torsten and Tiedemann, Ralph and Apio, Ann and Plath, Martin},
  title     = {Cover, food, competitors and individual densities within bushbuck Tragelaphus scriptus female clan home ranges},
  year      = {2006},
  abstract  = {We examined factors predicting female densities within the common home ranges of related females ("clans") in bushbuck Tragelaphus scriptus Pallas, 1776. In this species, each female forms an individual home range, but the home ranges of matrilineal clan members strongly overlap. We found female densities to increase in areas with high canopy cover. Moreover, individual home range sizes tended to decrease with increasing cover. Food plant availability and intruder pressure by two heterospecific competitors did not significantly affect female densities. Apparently, canopy cover is the major limited resource in this species. A possible explanation is that both adult bushbuck and - even more markedly - fawns hide from predators in dense vegetation, in particular in thicket clumps and coalescences. The study shows an effect of habitat properties (eg sufficient canopy cover) on a within-population level in bushbuck, where female densities differ even among proximate clan areas},
  language  = {en}
}
@article{WronskiApioWankeretal.2006,
  author    = {Wronski, Torsten and Apio, Ann and Wanker, R and Plath, Martin},
  title     = {Behavioural repertoire of the bushbuck (Tragelaphus scriptus): agonistic interactions, mating behaviour and parent-offspring relations},
  doi       = {10.1007/s10164-005-0186-y},
  year      = {2006},
  abstract  = {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},
  language  = {en}
}