8 research outputs found
At the crossroads of two biodiversity hotspots : the biogeographic patterns of Shimba Hills, Kenya
At the crossroads of two biodiversity hotspots; the biogeographic patterns of Shimba Hills, Kenya
Beryl A. Bwong
The Shimba Hills of Kenya (SHK) is geographically located at the cross roads of two major biodiversity hotspots; the Coastal Forests of Eastern Africa (CFEA) and the Eastern Afromontane Biodiversity Region, specifically the neighbouring Eastern Arc Mountains (EAM). Results from old and recent collections of its flora and fauna indicate that Shimba Hills harbour species associated with EAM and CFEA as well as taxa that have affinity with West African Guineo-Congolian forest. However, the link between SHK and these biodiversity hotspots has never been tested appropriately using phylogenetic approaches. Using 16S mtDNA, demographic analysis and species distribution modelling, I sought to understand the phylogeographic affiliation of Shimba Hills with the neighbouring CFEA and EAM using its amphibian assemblage. Three main questions were explored, namely: a) Which are the closest relatives of SHK amphibian populations? b) Do amphibian species currently occurring in SHK have similar phylogeographic patterns to each other? c) Which historical processes, if any, account for the observed patterns of genetic diversity? I found that SHK and indeed the entire study area have a complex biogeographic history and no single pattern can explain the current amphibian assemblage in the area. Shimba Hills are more closely affiliated to the CFEA than to the EAM. Two previously undocumented putative phylogeographic breaks are recovered from the study area; one from the Kenya north coast and another in the Tanga region in Tanzania. Historical habitat stability and connectivity appear to play a significant role in species diversification in the area. Additionally, I also report on some fundamental findings on Shimba Hills amphibians during this study; Using a combination of molecular, morphological, spatial and bioacoustics methods the taxonomic status of the only endemic amphibian from Shimba Hills, Hyperolius rubrovermiculatus, is confirmed and description of a new species from the north eastern Tanzania is proposed. Secondly the taxonomic status of a Callulina rediscovered in Shimba Hills after 50 years is confirmed and I also propose the description of three new species of Callulina from the neighbouring Eastern Arc Mountains in Tanzania. Finally, I took the opportunity to compile the first ever annotated checklist of amphibians of Shimba Hills National Reserve where a new country record for the Ribbon Caecilian (Scolecomorphus vittatus) and other interesting discoveries are discussed. The reserve plus the entire SHK area contains the highest number of amphibian diversity for any known locality in Kenya. Therefore its continued conservation will ensure about 30% of Kenya’s amphibian species are preserved.
Key words: Coastal forests, Eastern Arc Mountains, Phylogeography, species distribution modelling, checklist, Amphibians
Kitobo Forest of Kenya, a unique hotspot of herpetofaunal diversity
Herpetologically, the remoteness of Kitobo forest in south-eastern Kenya has partly contributed to it remaining virtually un-explored until 2007. Three surveys were conducted in December 2007, December 2009 and April 2010 aimed at generating a comprehensive list of the forest amphibians and reptiles. Using largely timed-species count method, 13 species of amphibians representing eight families and 32 reptiles belonging to 11 families were recorded. Overall species diversity was highest during the 2007 sampling. The richness and abundance of amphibians was highest during the April 2010 sampling period when the amount of rainfall was also highest. The results of species accumulation curves of the three sampling periods did not plateau demonstrating that more species occur in this forest. Pressure on this forest fragment from the adjacent local people is high which in addition to the annual floods threatens its long-term survival. For example the distribution and abundance of some forest associated species such as the tree frogs Leptopelis flavomaculatus and Hyperolius puncticulatus appear to fluctuate with flood events and may decline in future. Considering the forest associated herpetofanua recorded, Kitobo forest is zoogeographically assignable to the East African coastal forest biodiversity hotspot. The documentation of high species richness and diversity in this small forest fragment strongly highlight its biodiversity importance and place it among the most important sites for the conservation of reptiles and amphibians in Kenya
A new Reed Frog (Hyperoliidae: Hyperolius) from coastal northeastern Mozambique
Conradie, Werner, Verburgt, Luke, Portik, Daniel M., Ohler, Annemarie, Bwong, Beryl A., Lawson, Lucinda P. (2018): A new Reed Frog (Hyperoliidae: Hyperolius) from coastal northeastern Mozambique. Zootaxa 4379 (2): 177-198, DOI: https://doi.org/10.11646/zootaxa.4379.2.
Environmental correlates of phylogenetic endemism in amphibians and the conservation of refugia in the Coastal Forests of Eastern Africa
Aims To quantify the spatial distribution of amphibian phylogenetic endemism (PE), an indicator of potential refugia, to test PE for correlations with current and historical environmental predictors, and to evaluate the effectiveness of current protected areas at conserving evolutionary history. Location Coastal Forests of Eastern Africa (CFEA) and the adjacent low-elevation Eastern Afromontane (EA). Methods We integrated new and existing spatial and phylogenetic data to map PE for almost the full amphibian assemblage (41 of 55 species), including 35 intraspecific lineages from several species and complexes showing high phylogeographic structure. Using spatial and non-spatial regressive models, we tested whether PE can be predicted by measures of Quaternary climate change, forest stability, topographic heterogeneity and current climate. PE results were intersected with the protected area network to evaluate current conservation effectiveness. Results We detect refugia in Tanzania and coastal Kenya previously identified as CFEA centres of endemism but also new areas (lowland Tanga region and Pangani river, Zaraninge forest, Mafia island, Matumbi hills). Results show that refugia for amphibians (high PE) are located in areas with long-term Quaternary climate stability and benign current climate (high precipitation of driest quarter, high annual precipitation), with climatically unstable areas demonstrating low PE. Conservation analyses revealed that ten PE hotspots account for over 25% of the total PE, but only small parts of these areas are under conservation protection. Main Conclusions Utilizing cryptic diversity from novel phylogeographic data and distribution modelling improves our understanding of endemism patterns, with climate stability being strongly correlated with the distribution of PE. Our analyses point towards high PE areas being refugia, which require an urgent need to consolidate protected areas within centres of endemism in this highly threatened biodiversity hotspot.Humer Foundation via the Centre for African
Studies Basel; Stipendienkommission fĂĽr
Nachwuchskräfte; COSTECH, Grant/Award
Number: 2013-341-NA-2013-121; Freiwillige
Akademische Gesellschaft Basel (FAG); Kenya
Wildlife Service, Grant/Award Number: KWS/
BRM/5001. University of Basel Travel Fund.
Kenya Forest service permit, MUS/1/KFS/
VOL.II/
Amphibian Diversity in Shimba Hills National Reserve, Kenya: A Comprehensive List of Specimens and Species
We present the first annotated amphibian checklist of Shimba Hills National Reserve (SHNR). The list comprises of 30 currently known amphibians (28 anurans and two caecilians), which includes 11 families and 15 genera. In addition, individual records per species, distribution in the reserve and brief remarks about the species are presented. The checklist is based on information from museum collections, field guides, unpublished reports and newly collected field data. We are able to confirm the presence of two Eastern Afromontane species in the SHNR: Scolecomorphus cf. vittatus and Callulina cf. kreffti. The latter has not been recorded since the original collection of a single specimen over 50 years ago. SHNR contains the highest number of amphibian species of any known locality in Kenya (about 30% of the country’s total number); therefore it is of national conservation importance. Finally, we briefly discuss the biogeography of the SHNR and its connections to nearby biogeographic regions.Keywords: coastal forests, checklist, zoogeography, amphibians, Shimba Hill
The status of flora and fauna in the Nzoia River drainage basin in western Kenya
The species richness of flora and fauna in the Nzoia River drainage basin is documented through a study of museum specimens, catalogues and databases. The catchment area and basin covers 2.2% (12900/580367 km2) of Kenya’s total land area with an altitudinal range of 1140 to 4300 m and varied ecosystem and land uses. We recorded approximately 9.3% (3239/34677) of Kenya’s current known species of vascular plants, invertebrates (insects and spiders), fish, amphibians, reptiles, birds and mammals. Bird species made up the highest proportion 58.3% (650/1114) of the national total followed by amphibians 37.3% (41/110), reptiles 45.0% (86/191), mammals 31.3% (122/390), vascular plants 17.9% (1251/7000), fish 6.7% (58/872) (32.2% (58/180) for freshwater fish only) and invertebrates (insects and spiders) 4.1% (1031/25000). Ninety-five species recorded in this area are endemic to Kenya and 42 globally threatened. The species recorded contribute to several ecosystem services including pest control, pollination, bio-indicators, medicine and cosmetics, building materials, ecotourism, research and education. Data available differed substantially across counties and taxon groups with gaps apparent in five counties (Bungoma, Busia, Elgeyo Marakwet, Siaya and Usain Gishu) and four taxa plants, invertebrates, fungi and bacteria where a dearth of information exists. To fill these gaps we recommend prioritisng future survey effort on taxa and counties with fewer than 10% of the total numbers of records