Kenneth Otieno Onditi

Dr. Kenneth Otieno Onditi

Kunming Institute of Zoology, Chinese Academy of Sciences
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 February 2020 in Ecology and Evolution
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Journal Article
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ZCZheng Zhong Chen
Zheng Zhong Chen
Xueyou LiXueyou Li
Xueyou Li
WSWenyu Song
Wenyu Song
QLQuan Li
Quan Li
KOKenneth Otieno Onditi
Kenneth Otieno Onditi
XJXue-Long Jiang
Xue-Long Jiang
Understanding the species diversity patterns along elevational gradients is critical for biodiversity conservation in mountainous regions. We examined the elevational patterns of species richness and turnover, and evaluated the effects of spatial and environmental factors on nonvolant small mammals (hereafter “small mammal”) predicted a priori by alternative hypotheses (mid‐domain effect [MDE], species–area relationship [SAR], energy, environmental stability, and habitat complexity]) proposed to explain the variation of diversity. We designed a standardized sampling scheme to trap small mammals at ten elevational bands across the entire elevational gradient on Yulong Mountain, southwest China. A total of 1,808 small mammals representing 23 species were trapped. We observed the hump‐shaped distribution pattern of the overall species richness along elevational gradient. Insectivores, rodents, large‐ranged species, and endemic species richness showed the general hump‐shaped pattern but peaked at different elevations, whereas the small‐ranged species and endemic species favored the decreasing richness pattern. The MDE and the energy hypothesis were supported, whereas little support was found for the SAR, the environmental stability hypothesis, and the habitat complexity. However, the primary driver(s) for richness patterns differed among the partitioning groups, with NDVI (the normalized difference vegetation index) and MDE being the most important variables for the total richness pattern. Species turnover for all small mammal groups increased with elevation, and it supported a decrease in community similarity with elevational distance. Our results emphasized for increased conservation efforts in the higher elevation regions of the Yulong Mountain.

1 January 2020 in Zoological Research
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Journal Article
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WSWen-Yu Song
Wen-Yu Song
Xueyou LiXueyou Li
Xueyou Li
ZCZhong-Zheng Chen
Zhong-Zheng Chen
QLQuan Li
Quan Li
KOKenneth Otieno Onditi
Kenneth Otieno Onditi
XJXue-Long Jiang
Xue-Long Jiang
One of the fundamental inquiries into interpreting patterns of biodiversity is to disentangle geographical and environmental variables. Disjunct alpine communities are geographically isolated from one another that experience similar harsh environmental impacts. The isolated but homogenous habitats might promote speciation but constrain functional traits variation. In this study, we examined the hypothesis that dispersal limitation promotes taxonomic divergence, while habitat similarity in alpine mountains leads to functional convergence. We performed standardized field investigation to sample non-volant small mammals from 18 prominent alpine sites in the Three Parallel Rivers area. We estimated indices quantifying taxonomic and functional alpha- and beta-diversity, as well as beta-diversity components. We then assessed the respective importance of geographical and environmental predictors in explaining taxonomic and functional compositions. No evidence showed that species were more functionally similar than expected in local assembling. However, the taxonomic turnover components were higher than functional ones (0.471±0.230 vs. 0.243±0.215), while the nestedness components were the contrary (0.063±0.054 vs. 0.269±0.225), indicated the difference of taxonomic compositions between the sites are raised by replacements of species that are functionally similar. Further, geographical barriers was the key factor influencing both taxonomic total dissimilarity and turnover component, whereas functional beta-diversity was primarily explained by climatic factors such as min temperature of coldest month. Our findings provide more empirical evidence that taxonomic and functional diversity patterns can be independently driven by different ecological processes. Our results point to the importance of decomposing different components of beta-diversity to understand the underlying mechanisms of community assembling. These results also shed light on the assembly rules and ecological processes of terrestrial mammal communities in extreme environments.

5 January 2022 in Frontiers in Ecology and Evolution
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Journal Article
Open access
KOKenneth Otieno Onditi
Kenneth Otieno Onditi
WSWen-Yu Song
Wen-Yu Song
XLXue-You Li
Xue-You Li
ZCZhong-Zheng Chen
Zhong-Zheng Chen
QLQuan Li
Quan Li
XJXue-Long Jiang
Xue-Long Jiang
Mountains of the Afrotropics are global biodiversity hotspots and centers of speciation and endemism; however, very few studies have focused on the phylogenetic and functional dimensions of Afromontane small mammals. We investigated the patterns and mechanisms of small mammal phylogenetic and functional diversity and assembly along elevational gradients in Mount Kenya, the second highest mountain in Africa, and a contrasting low mountain range, Chyulu Hills. We sampled 24 200-m interval transects in both sites; 18 in Mt. Kenya (9 each in the windward side, Chogoria, and the leeward side, Sirimon) and 6 in Chyulu. We extracted the mitochondrialCytochrome bgene to reconstruct a time-calibrated species tree for estimating phylogenetic diversity indices [phylogenetic richness (PD), mean nearest taxon distance (PDMNTD), and nearest taxon index (PDNTI)]. A functional trait data set was compiled from the field-recorded measurements and published data sets for estimating functional diversity indices [functional richness (FD), mean nearest taxon distance (FDMNTD), and nearest taxon index (FDNTI)]. Several environmental variables representing water-energy availability, primary habitat productivity, and topographic heterogeneity were used to estimate the predictive power of abiotic conditions on diversity variances using generalized linear and generalized additive regression models. The PD and FD peaked around mid-elevations in Mt. Kenya, unimodally increased or decreased in Chogoria and Sirimon, and monotonically increased in Chyulu. The divergence and community structure indices—PDMNTD, FDMNTD, and PDNTIand FDNTI—were relatively weakly associated with elevation. Overall, the tendency of assemblages to be phylogenetically and functionally closely related than expected by chance decreased with elevation in Mt. Kenya but increased in Chyulu. Across the indices, the annual precipitation and topographic ruggedness were the strongest predictors in Mt. Kenya, evapotranspiration and temperature seasonality were the strongest predictors in Chyulu, while temperature seasonality and terrain ruggedness overlapped as the strongest predictors in Chogoria and Sirimon in addition to annual precipitation in the latter and normalized difference vegetation index in the former. The observed contrasting trends in diversity distribution and the strongest predictors between elevational gradients are integral to the sustainable management of the high faunal biodiversity in tropical Afromontane ecosystems.

18 January 2019 in Zoological Research
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Journal Article
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SMSimon Musila
Simon Musila
ZCZheng Zhong Chen
Zheng Zhong Chen
QLQuan Li
Quan Li
RYRichard Yego
Richard Yego
BZBin Zhang
Bin Zhang
XJXue-Long Jiang
Xue-Long Jiang
The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals (hereafter 'small mammals') on Mt. Kenya, the second tallest mountain in Africa, using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern (Chogoria) and western (Sirimon) slopes. A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights. Abundance was highest at mid-elevations on both slopes. However, species richness and distribution patterns differed between the two slopes. More species were recorded on Chogoria (24) than on Sirimon (17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation (2 800 m a.s.l.), whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya's mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of small mammal diversity in mountain habitats in Africa.

28 November 2023 in ZooKeys
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ZSZifan Shi
Zifan Shi
HYHongfeng Yao
Hongfeng Yao
KHKai He
Kai He
WBWeipeng Bai
Weipeng Bai
JZJiaJun Zhou
JiaJun Zhou
ZCZheng Zhong Chen
Zheng Zhong Chen
The hedgehog genus Mesechinus (Erinaceidae, Eulipotyphla) is currently comprised of four species, M. dauuricus, M. hughi, M. miodon, and M. wangi. Except for M. wangi, which is found in southwestern China, the other three species are mainly distributed in northern China and adjacent Mongolia and Russia. From 2018 to 2023, we collected seven Mesechinus specimens from Anhui and Zhejiang provinces, eastern China. Here, we evaluate the taxonomic and phylogenetic status of these specimens by integrating molecular, morphometric, and karyotypic approaches. Our results indicate that the Anhui and Zhejiang specimens are distinct from the four previously recognized species and are a new species. We formally described it here as Mesechinus orientalissp. nov. It is the only Mesechinus species occurring in eastern China and is geographically distant from all known congeners. Morphologically, the new species is most similar to M. hughi, but it is distinguishable from that species by the combination of its smaller size, shorter spines, and several cranial characteristics. Mesechinus orientalis sp. nov. is a sister to the lineage composed of M. hughi and M. wangi from which it diverged approximately 1.10 Ma.

13 September 2021 in Biodiversity and Conservation
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KOKenneth Otieno Onditi
Kenneth Otieno Onditi
Xueyou LiXueyou Li
Xueyou Li
WSWenyu Song
Wenyu Song
QLQuan Li
Quan Li
SMSimon Musila
Simon Musila
XJXue-Long Jiang
Xue-Long Jiang
Merely designating new and/or expanding existing protected areas (PAs) does not guarantee the protection of critical ecosystems and species. The management of PAs must be effective to sustain meaningful conservational outcomes. We inferred the management effectiveness of PAs in Kenya based on the representation of ranges and distribution of multiple diversity dimensions of terrestrial mammals and their association with governance and designation types. We hypothesized that different governance types underlie variable management efficacies, such that stricter-managed PAs have better habitats that attract more wildlife, translating to higher species diversity compared to less strictly-managed PAs, especially for focal species groups (large carnivores, large herbivores, and endangered species). The results showed nearly all terrestrial mammals in Kenya represented in at least one PA. However, the relative proportion of represented ranges were low, and analysis of spatial conservation prioritization showed significant expansion beyond current PAs needed to achieve a one third coverage of focal species’ ranges in a best-solution reserve system. Differences in PA governance and designation types were not systematically associated with diversity variances, and while there were more unique species in state-managed PAs than in privately-managed ones, averaged diversity coefficients were comparable between categories. Diversity variances explained by PA size and status year were low in a combined species pool but increased in focal species groups. These findings suggest that success in terrestrial mammal conservation in PAs in Kenya require clearly and formally streamlined definition, performance feedback, and collaboration terms between state-managed and privately-managed PAs.