29 research outputs found

    Status and behavioural ecology of Sengis in the Boni-Dodori and Arabuko-Sokoke forests, Kenya, determined by camera traps

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    The biodiversity of northern coastal Kenya, east of the Tana River, is poorlyunderstood because security problems and poor infrastructure have discouraged accessto the area. However, the wooded areas in the region have great potential forharbouring endemic and rare species, including sengis or elephant-shrews (orderMacroscelidea), especially giant sengis in the genus Rhynchocyon. Based on extensivecamera-trap surveys of the Boni-Dodori forest, east of the Tana River near theSomalia border, and the Arabuko-Sokoke forest west of the Tana River, the goldenrumpedsengi Rhynchocyon chrysopygus appears to be limited to the Arabuko-Sokokearea, while the giant sengi in the Boni-Dodori forest is different. The Boni-Dodoriforest, the largest Kenyan coastal forest, with a potential forest and thicket area of atleast 3000 km2 is likely to hold a significant number of Rhynchocyon, making it veryimportant to sengi conservation. The study generated over 2700 images of giant sengiand 32 000 camera-trap images of soft-furred sengi in a total surveyed area ofapproximately 300 km2 providing the first detailed 24-hour behaviour data for thespecies. The circadian patterns have confirmed R. chrysopygus and Boni Rhynchocyonto be strictly diurnal while the soft-furred sengi were mostly nocturnal. Occupancy forRhynchocyon was over 80 percent for both the Boni forest thicket and Arabuko-Sokoke Cynometra forest thicket. Occupancy and trapping rates for the soft-furred sengi were significantly higher for the Arabuko-Sokoke forest than the Boni-Dodori forest. It was not possible in the camera trap images to reliably differentiate between the two soft-furred sengi species, four-toed sengi Petrodromus tetradactylus and rufous sengi Elephantulus rufescens, known to occur in the area.Keywords: Macroscelidea, elephant-shrew, Rhynchocyon, abundance, distribution,activity patter

    Abundance, distribution, habitat, activity and conservation of Sokoke bushy-tailed mongoose Bdeogale omnivora in central and north coast forests of Kenya

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    The Sokoke dog or bushy-tailed mongoose Bdeogale omnivora is poorly known and considered to be endemic to the East African coastal forests. Systematic camera trap surveys, comprising 9229 camera trap days on grids at six study sites, were used to determine the distribution and relative abundance of the Sokoke bushy-tailed mongoose in the two largest Kenyan coastal forests: Boni-Dodori Forest Complex (ca. 4000 km²); and Arabuko-Sokoke Forest Reserve (416 km²). This species was captured in all surveyed forests with significantly more detections in Brachystegia woodland habitat (ca. 71 km2) of Arabuko-Sokoke and the Boni forest sectors (ca. 2000 km2) of the Boni-Dodori Forest Complex. Boni-Dodori Forest Complex, with an estimated occupancy of over 60% for this species, holds a significant population. The study generated over 1000 images of the Sokoke bushy-tailed mongoose in a total surveyed area of approximately 500 km2 providing the first 24-hour activity data for the species. The circadian patterns confirm this species to be strictly nocturnal. This study strongly recommends that its Red List status remains ‘Vulnerable’. The few remaining coastal forests continue to face human pressure. Recent proposals to find and extract hydrocarbons from under the Arabuko-Sokoke Forest, and the planned major development close to Boni-Dodori Forest Complex, raise serious conservation concerns for this exceptionally biodiverse ecosystem.Keywords: Arabuko-Sokoke forest, Boni forest, Dodori forest, camera trap, status, Bdeogale omnivor

    Africa's forgotten forests: the conservation value of Kenya's Northern coastal forests for large mammals

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    There are two PFS for this article, one is the original article and the other is an Erratum specifying the errors in the original article.In comparison to other ecosystems in east Africa, the biodiversity of the coastal forests of Kenya’s northern coastline is poorly documented, even in the case of large terrestrial mammals. In response to this, we undertook a systematic survey of the Boni-Dodori forests using four camera trap grids with camera spacing of 2 km covering 300 km2 over 7020 camera trap days. We recorded 37 mammal species and derived camera trap rates and estimated occupancy for 31 medium-to-large terrestrial species, some of which represent range extensions. Remarkably, the critically endangered Aders’ duiker was the most frequently recorded species. A distinctive form of giant sengi and the vulnerable Sokoke bushy-tailed mongoose were also widely distributed and relatively abundant. Other significant records of threatened species included African wild dog, African lion and Pousargues’s monkey. Species richness and relative abundance of all species were higher than that recorded for Arabuko-Sokoke Forest, Kenya’s only other large coastal forest, using the same camera trap survey protocol.Keywords: Boni-Dodori forest, coastal forest, camera trapping, mammals, species richness, trap rates, occupanc

    Splitting or Lumping? A Conservation Dilemma Exemplified by the Critically Endangered Dama Gazelle (Nanger dama)

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    Managers of threatened species often face the dilemma of whether to keep populations separate to conserve local adaptations and minimize the risk of outbreeding, or whether to manage populations jointly to reduce loss of genetic diversity and minimise inbreeding. In this study we examine genetic relatedness and diversity in three of the five last remaining wild populations of dama gazelle and a number of captive populations, using mtDNA control region and cytochrome b data. Despite the sampled populations belonging to the three putative subspecies, which are delineated according to phenotypes and geographical location, we find limited evidence for phylogeographical structure within the data and no genetic support for the putative subspecies. In the light of these data we discuss the relevance of inbreeding depression, outbreeding depression, adaptive variation, genetic drift, and phenotypic variation to the conservation of the dama gazelle and make some recommendations for its future conservation management. The genetic data suggest that the best conservation approach is to view the dama gazelle as a single species without subspecific divisions

    Splitting or lumping? A conservation dilemma exemplified by the critically endangered Dama Gazelle (Nanger dama)

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    Managers of threatened species often face the dilemma of whether to keep populations separate to conserve local adaptations and minimize the risk of outbreeding, or whether to manage populations jointly to reduce loss of genetic diversity and minimise inbreeding. In this study we examine genetic relatedness and diversity in three of the five last remaining wild populations of dama gazelle and a number of captive populations, using mtDNA control region and cytochrome b data. Despite the sampled populations belonging to the three putative subspecies, which are delineated according to phenotypes and geographical location, we find limited evidence for phylogeographical structure within the data and no genetic support for the putative subspecies. In the light of these data we discuss the relevance of inbreeding depression, outbreeding depression, adaptive variation, genetic drift, and phenotypic variation to the conservation of the dama gazelle and make some recommendations for its future conservation management. The genetic data suggest that the best conservation approach is to view the dama gazelle as a single species without subspecific divisions

    Monitoring rarity: the critically endangered Saharan cheetah as a flagship species for a threatened ecosystem.

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    Deserts are particularly vulnerable to human impacts and have already suffered a substantial loss of biodiversity. In harsh and variable desert environments, large herbivores typically occur at low densities, and their large carnivore predators occur at even lower densities. The continued survival of large carnivores is key to healthy functioning desert ecosystems, and the ability to gather reliable information on these rare low density species, including presence, abundance and density, is critical to their monitoring and management. Here we test camera trap methodologies as a monitoring tool for an extremely rare wide-ranging large felid, the critically endangered Saharan cheetah (Acinonyx jubatus hecki). Two camera trapping surveys were carried out over 2-3 months across a 2,551 km2 grid in the Ti-n-haÄŸÄŸen region in the Ahaggar Cultural Park, south central Algeria. A total of 32 records of Saharan cheetah were obtained. We show the behaviour and ecology of the Saharan cheetah is severely constrained by the harsh desert environment, leading them to be more nocturnal, be more wide-ranging, and occur at lower densities relative to cheetah in savannah environments. Density estimates ranged from 0.21-0.55/1,000 km2, some of the lowest large carnivore densities ever recorded in Africa, and average home range size over 2-3 months was estimated at 1,583 km2. We use our results to predict that, in order to detect presence of cheetah with p>0.95 a survey effort of at least 1,000 camera trap days is required. Our study identifies the Ahaggar Cultural Park as a key area for the conservation of the Saharan cheetah. The Saharan cheetah meets the requirements for a charismatic flagship species that can be used to "market" the Saharan landscape at a sufficiently large scale to help reverse the historical neglect of threatened Saharan ecosystems

    Conservation in Saudi Arabia; moving from strategy to practice

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    Conservation in the Kingdom of Saudi Arabia is relatively young, yet have made considerable gains in conservation through strategic proclamation and reintroductions. Changes in land use, illegal hunting and competition with domestic stock has decimated the native ungulates, meaning that the survival of the native ungulate species is now completely dependent on protected area network. The challenge is to sustain this network to make meaningful conservation impact into the future. We review the status of ungulate conservation in Saudi Arabia and highlight that the conservation strategy is well developed. The major challenge faced in conservation in Saudi Arabia now is to implement what has been sanctioned

    Phylogenetic reanalysis of the Saudi gazelle and its implications for conservation

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    Abstract:The identification of taxonomically appropriate populations of endangered species for captive breeding and reintroduction programs is fundamental to the success of those programs. The Saudi gazelle ( Gazella saudiya) was endemic to the Arabian peninsula but is now considered extinct in the wild and is potentially a candidate for captive breeding and reintroduction. Using 375 base pairs of mitochondrial DNA (mtDNA) cytochrome b gene derived from museum samples collected from the wild prior to the presumed extinction of this species, we show that G. saudiya is the sister taxon of the African dorcas gazelle ( G. dorcas). Reciprocal monophyly of G. saudiya mtDNA haplotypes with G. dorcas, coupled with morphological distinctiveness, suggests that it is an evolutionarily significant unit. These data indicate that captive populations identified previously as potential sources of G. saudiya for captive breeding appear incorrectly designated and are irrelevant to the conservation of G. saudiya. The polymerase chain reaction–restriction fragment length polymorphism ( PCR-RFLP) analysis of several private collections of living gazelles in Saudi Arabia provides no evidence for the survival of G. saudiya. We recommend that field surveys be undertaken to establish whether G. saudiya is indeed extinct in the wild and that other private collections within the Arabian peninsula be screened genetically. We urge caution when captive animals of unknown provenance are used to investigate the phylogenetics of cryptic species groups. Resumen: La identificación de poblaciones taxonómicamente apropiadas de especies en peligro para programas de reproducción en cautiverio y de reintroducción es fundamental para su éxito. La Gacela Saudi (Gazella saudiya) fue endémica a la península de Arabia pero ahora está considerada como extinta en su medio y es un candidato potencial para reproducción en cautiverio y reintroducción. Utilizando 375 pares de bases de ADN mitocondrial (ADNmt) del gene citocromo b derivados de muestras de museos colectadas en el medio silvestre antes de la extinción de la especie, mostramos que G. saudiya es el taxón hermano de la gacela dorcas africana (G. dorcas). La monofilia recíproca de haplotipos de ADNmt de G. saudiya con G. dorcas, aunado a diferencias morfológicas, sugiere que es una unidad evolutiva significativa. Estos datos indican que las poblaciones cautivas identificadas previamente como fuente potencial de G. saudiya para reproducción en cautiverio están incorrectamente identificadas y son irrelevantes para la conservación de G. saudiya. El análisis PCR-RFLP de varias colecciones privadas de gacelas vivas en Arabia Saudita no proporcionan evidencia para la supervivencia de G. saudiya. Recomendamos que se realicen muestreos en el campo para establecer si en efecto G. saudiya está extinta en su hábitat y que se examinen genéticamente las otras colecciones privadas en la península Arábiga. Recomendamos precaución cuando animales cautivos de origen desconocido son utilizados para investigar la filogenia de grupos de especies crípticas
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