79 research outputs found
Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds
No full textVenkataraman, Vivek V., Kerby, Jeffrey T., Nguyen, Nga, Ashenafi, Zelealem Tefera, Fashing, Peter J. (2015): Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds. Journal of Mammalogy 96 (1): 129-137, DOI: 10.1093/jmammal/gyu013, URL: http://dx.doi.org/10.1093/jmammal/gyu01
Fig. 1.—A in Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds
No full textFig. 1.—A) An Afroalpine rodent among geladas (Theropithecus gelada); B and C) Ethiopian wolves (Canis simensis) foraging for rodents among geladas; and D) an Ethiopian wolf successfully captures a rodent while among geladas (photograph in c reproduced with permission from Malcolm Ramsay).Published as part of Venkataraman, Vivek V., Kerby, Jeffrey T., Nguyen, Nga, Ashenafi, Zelealem Tefera & Fashing, Peter J., 2015, Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds, pp. 129-137 in Journal of Mammalogy 96 (1) on page 130, DOI: 10.1093/jmammal/gyu013, http://zenodo.org/record/784964
Fig. 3 in Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds
No full textFig. 3.—Monthly counts of encounters between Ethiopian wolves (Canis simensis) and geladas (Theropithecus gelada) from April 2007 to April 2008. Data were adjusted for observation days per month and September 2007 was excluded due to low sample size.Published as part of Venkataraman, Vivek V., Kerby, Jeffrey T., Nguyen, Nga, Ashenafi, Zelealem Tefera & Fashing, Peter J., 2015, Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds, pp. 129-137 in Journal of Mammalogy 96 (1) on page 133, DOI: 10.1093/jmammal/gyu013, http://zenodo.org/record/784964
Fig. 4 in Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds
No full textFig. 4.—Stacked barplot depicting proportions of successful and unsuccessful predation attempts by Ethiopian wolves (Canis simensis) on rodents observed during July and August 2011. Wolves had more successful attempts catching rodents in the presence of geladas (16/24 = 66.7%) than when alone (15/61 = 25%). White numbers represent counts.Published as part of Venkataraman, Vivek V., Kerby, Jeffrey T., Nguyen, Nga, Ashenafi, Zelealem Tefera & Fashing, Peter J., 2015, Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds, pp. 129-137 in Journal of Mammalogy 96 (1) on page 134, DOI: 10.1093/jmammal/gyu013, http://zenodo.org/record/784964
Fig. 2 in Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds
No full textFig. 2.—Histogram of encounter times between Ethiopian wolves (Canis simensis) and geladas (Theropithecus gelada) from January 2007 to April 2008. Encounters peaked during the mid-day (X = 1328 h) and coincide with the peak aboveground activity of rodents and the foraging activity of geladas and Ethiopian wolves.Published as part of Venkataraman, Vivek V., Kerby, Jeffrey T., Nguyen, Nga, Ashenafi, Zelealem Tefera & Fashing, Peter J., 2015, Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds, pp. 129-137 in Journal of Mammalogy 96 (1) on page 133, DOI: 10.1093/jmammal/gyu013, http://zenodo.org/record/784964
Foraging ecology of African wolves (Canis lupaster) and its implications for the conservation of Ethiopian wolves (Canis simensis)
No full textAfrican wolves (AWs) are sympatric with endangered Ethiopian wolves (EWs) in parts of their range. Scat analyses have suggested a dietary overlap between AWs and EWs, raising the potential for exploitative competition, and a possible conservation threat to EWs. However, in contrast to that of the well-studied EW, the foraging ecology of AWs remains poorly characterized. Accordingly, we studied the foraging ecology of radio-collared AWs (n = 11 individuals) at two localities with varying levels of anthropogenic disturbance in the Ethiopian Highlands, the Guassa-Menz Community Conservation Area (GMCCA) and Borena-Saynt National Park (BSNP), accumulating 845 h of focal observation across 2952 feeding events. We also monitored rodent abundance and rodent trapping activity by local farmers who experience conflict with AWs. The AW diet consisted largely of rodents (22.0%), insects (24.8%), and goats and sheep (24.3%). Of the total rodents captured by farmers using local traps during peak barley production (July to November) in GMCCA, averaging 24.7 ± 8.5 rodents/hectare/day, 81% (N = 3009) were scavenged by AWs. Further, of all the rodents consumed by AWs, most (74%) were carcasses. These results reveal complex interactions between AWs and local farmers, and highlight the scavenging niche occupied by AWs in anthropogenically altered landscapes in contrast to the active hunting exhibited by EWs in more intact habitats. While AWs cause economic damage to local farmers through livestock predation, they appear to play an important role in scavenging pest rodents among farmlands, a pattern of behaviour which likely mitigates direct and indirect competition with EWs. We suggest two routes to promote the coexistence of AWs and EWs in the Ethiopian highlands: local education efforts highlighting the complex role AWs play in highland ecosystems to reduce their persecution, and enforced protection of intact habitats to preserve habitat preferred by EWs
Bryobia abyssiniae (Prostigmata: Tetranychidae), a new species from the highlands of Ethiopia
No full textBryobia abyssiniae Fashing & Ueckermann, a recently discovered species, is described using DNA-barcoding as well as morphological features of the adult female and all post-embryonic instars. The species is characterized by remarkable propodosomal lobe variation. A lack of variation in molecular markers indicates that the several forms observed reflect intraspecific variability in this apparently all-female species. Its host plant, a giant lobelia (Lobelia rhynchopetalum Hemsl.; Campanulaceae), is endemic to the Ethiopian highlands. A discussion of climate at the collection locality, the host plant, and notes on biology are also included. Additionally, we suggest that a minimum of 5% sequence difference in the mitochondrial cytochrome c oxidase subunit I region will be needed to differentiate Bryobia specie
Geographic distribution of microsatellite alleles in geladas (Primates, Cercopithecidae): Evidence for three evolutionary units
No full textThe subspecific taxonomy and distribution of geladas (Theropithecus gelada Rüppell, 1835) remains uncertain. Recent molecular studies based on mitochondrial sequence data revealed a geographically structured, three‐deme population, suggesting that there are three evolutionary units of geladas. However, mitochondrial distributions do not always recover population relationships, particularly in taxa with a complex history of isolation and gene flow. We therefore analysed the nuclear genetic population structure of the global gelada population based on 20 microsatellite loci in 43 samples from across its geographic range. FST values, a STRUCTURE analysis and a principal coordinate analysis (PCoA) confirmed the three‐deme population structure corresponding to the mitochondrial population structure. Therefore, our analyses provide additional support for three evolutionary units in geladas, corresponding to (a) a northern (north of Lake Tana, primarily in the Simien Mountains, previously classified as Theropithecus gelada gelada Rüppell, 1835), (b) a central (between Addis Ababa and the highlands east of Lake Tana, previously classified as Theropithecus gelada obscurus Heuglin, 1863) and (c) a southern (south of the Rift Valley, previously tentatively classified as Theropithecus gelada arsi Shotake et al., 2016, Anthropological Science, 124, 157) population. These results pave the way for future conservation decisions and highlight that the gelada population boundaries need more fine‐grained genetic sampling and phenotypic analyses, in particular for their taxonomic ranking
Competition between sympatric wolf taxa: an example involving African and Ethiopian wolves
No full textCarnivore populations are declining globally due to range contraction, persecution and prey depletion. One consequence of these patterns is increased range and niche overlap with other carnivores, and thus an elevated potential for competitive exclusion. Here, we document competition between an endangered canid, the Ethiopian wolf (EW), and the newly discovered African wolf (AW) in central Ethiopia. The diet of the ecological specialist EW was dominated by rodents, whereas the AW consumed a more diverse diet also including insects and non-rodent mammals. EWs used predominantly intact habitat, whereas AWs used mostly areas disturbed by humans and their livestock. We observed 82 encounters between the two species, of which 94% were agonistic. The outcomes of agonistic encounters followed a territory-specific dominance pattern, with EWs dominating in intact habitat and AWs in human-disturbed areas. For AWs, the likelihood of winning encounters also increased with group size. Rodent species consumed by EWs were also available in the human-disturbed areas, suggesting that these areas could be suitable habitat for EWs if AWs were not present. Increasing human encroachment not only affects the prey base of EWs, but also may impact their survival by intensifying competition with sympatric AWs.Version of Recor
Home range, habitat use, and activity patterns of African wolves (Canis lupaster) in the Ethiopian highlands
No full textAfrican wolves (Canis lupaster) and Ethiopian wolves (C. simensis) occur often sympatrically across habitats in the Ethiopian Highlands, with recent studies finding evidence for interspecific competition. However, unlike the well-studied Ethiopian wolf, comparatively little is known about the ecology of the African wolf in the Ethiopian Highlands. To address this empirical gap, we collected data on home range size, habitat use, and activity patterns of radio-collared African wolves at the Guassa Menz Community Conservation Area (GCCA) and Borena Saynt Worehimenu National Park (BSNP). We followed the African wolves (5 in GCCA, 6 in BSNP) for 16 months and had 659 ± 83 encounters with each individual. The mean 95% kernel density estimate home range size of African wolves was higher in BSNP (4.5 ± 1.5 km2) than at GCCA (2.2 ± 0.7 km2). In 55% (n = 3934) of the encounters the wolves were found to be solitary, whereas in other encounters we found them in groups of two to seven. At both sites, the African wolves were more often found in areas close to human settlements than in more intact habitat, and they were mainly active at dawn and dusk. These results show flexibility in African wolf socioecology in response to habitat fragmentation and anthropogenic disturbance. We recommend further studies on major causes of spatial and temporal niche partitioning of Ethiopian wolves and African wolves in the Ethiopian Highlands
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