Phylogenetic relationships in the genus Leonardoxa (Leguminosae: Caesalpinioideae) inferred from chloroplast trnL intron and trnL-trnF intergenic spacer sequences

The African genus LEONARDOXA: (Leguminosae: Caesalpinioideae) comprises two Congolean species and a group of four mostly allopatric subspecies principally located in Cameroon and clustered together in the L. africana complex. LEONARDOXA: provides a good opportunity to investigate the evolutionary history of ant-plant mutualisms, as it exhibits various grades of ant-plant interactions from diffuse to obligate and symbiotic associations. We present in this paper the first molecular phylogenetic study of this genus. We sequenced both the chloroplast DNA trnL intron (677 aligned base pairs [bp]) and trnL-trnF intergene spacer (598 aligned bp). Inferred phylogenetic relationships suggested first that the genus is paraphyletic. The L. africana complex is clearly separated from the two Congolean species, and the integrity of the genus is thus in question. In the L. africana complex, our data showed a lack of congruence between clades suggested by morphological and chloroplast characters. This, and the low level of molecular divergence found between subspecies, suggests gene flow and introgressive events in the L. africana complex.     

The state of exploitation of the commercial demersal fishery of Cameroon

The state of exploitation of the demersal fisheries resources of Cameroon has been assessed using the classic Schaefer's (1954) model and the Gulland'ss (1961) moving average. The euilibrium yield found with the Schaefer method is statistically different (95 % probability) and higher than the Gulland approach. Because equilibrium models consistently over-estimate MSY and its related optimum effort, management option should target the 95 % value of the estimated parameters. The resources are being over-fished; as an immediate alternative to the urgent concern, catch and/or effort quotas could be allocated to the various fishing companies, with the total allocated catch and/or effort (for all fishing companies) 5% less than the estimated parameters. Enforcement control of that policy would be simplified as fishing activities are localised in the two main estuaries of the “Cameroon River” and Riodel-Rey;results should be complemented by economic studies of the fishery, as these economic factors would explain or better predict the behaviour of the fishing industry.     

Studies in African Cyperaceae 29. Scleria afroreflexa, a new species from western Cameroon

A new rare species, Scleria afroreflexa. is descriped from an upland area (1500 m) of South west Cameroon. It is most similar to S. sheilae Rayn., another rare species only known from one collection from a rocky habitat at 800 m near Yaounde in southeastern Cameroon. S. afroreflexa differs, however, in its more dense inflorescence with reflexed branches, its more hairy leaves, smaller achenes and in its montane habitat. Notes on habitat, ecology, distribution and conservation are given for the two species.     

A new dwarf Coffea (Rubiaceae) from southern Cameroon

A distinctive new species of dwarf monocaulous Coffea (Rubiaceae) from Cameroon is described and illustrated. Coffea mapiana is the second dwarf monocaulous known from Cameroon. Its diagnostic characters are elucidated and its taxonomic affinities are discussed; a conservation assessment is provided.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 425–430.     

Diet choice of large carnivores in northern Cameroon

The diet of African wild dogs, lions and spotted hyenas was studied in the woodland savannah of Faro National Park and surrounding hunting zones in northern Cameroon during the dry season. Faecal analysis revealed that the diet of the three large carnivores overlaps considerably. Frequencies of prey remains of large and medium‐sized antelopes were highest, with Buffon's kob being by far the most common prey species. Carnivores seem to consume the most abundant prey species. No prey item of domestic livestock was found in the faeces. Faecal analysis has proved to be a useful method to reveal diet choice for large carnivores in northern Cameroon. Detailed information on the distribution and density of large carnivores and their prey is needed to give a better picture of the status of carnivores in northern Cameroon and to help resolve conflicts with livestock. Further investigations into the seasonal variation of predation and other factors structuring the large carnivore community in northern Cameroon are recommended.     

Diet choice of large carnivores in northern Cameroon

The diet of African wild dogs, lions and spotted hyenas was studied in the woodland savannah of Faro National Park and surrounding hunting zones in northern Cameroon during the dry season. Faecal analysis revealed that the diet of the three large carnivores overlaps considerably. Frequencies of prey remains of large and medium‐sized antelopes were highest, with Buffon's kob being by far the most common prey species. Carnivores seem to consume most abundant prey species. No prey item of domestic livestock was found in the faeces. Faecal analysis has proved to be a useful method to reveal diet choice for large carnivores in northern Cameroon. Detailed information on the distribution and density of large carnivores and their prey is needed to give a better picture of the status of carnivores in northern Cameroon and to help resolve conflicts with livestock. Further investigations into the seasonal variation of predation and other factors structuring the large carnivore community in northern Cameroon are recommended.     

Comparative avian phylogeography of Cameroon and equatorial Guinea mountains: implications for conservation

We illustrate the use of Faith's 'Phylogenetic Diversity' measure to compare the phylogeographic structure of two bird species with patterns of avian endemism across six mountains in Cameroon and Equatorial Guinea. The Mountain Greenbul and Cameroon Blue-headed Sunbird showed phylogeographic patterns that together defined three biogeographic regions: Bioko, Mt. Cameroon, and the northern mountains of Cameroon. In contrast, the distributions of endemic species were largely a function of geographical distance, with close mountains sharing more endemic species than distant mountains. Moreover, for both species, populations on Mt. Cameroon were distinctive with respect to the ecologically relevant character bill size. Our results, while preliminary, illustrate the utility of a comparative approach for identifying geographical regions that harbour evolutionarily distinct populations and caution against using only the distributional patterns of endemics to prioritize regions for conservation. Results show that patterns of endemism may not be concordant with patterns of phylogenetic diversity nor morphological variation in a character important in fitness. While incorporation of additional species from unrelated taxa will be necessary to draw definitive conclusions about evolutionarily distinct regions, our preliminary results suggest a conservation approach for the Afromontane region of the Gulf of Guinea that would: (i) emphasize protection of both Bioko and Mt. Cameroon, thereby maximizing preservation of within-species phylogenetic and morphologic diversity; (ii) emphasize protection within the northern mountains to further conserve intraspecific phylogenetic diversity and maximize protection of endemic species.     

Stream degradation,fish abundance and the potential viability of ornamental fisheries in south-western Cameroon

Fifteen sites on nine second- and third-order streams in the Mount Cameroon area, with varying degrees of human disturbance, were sampled during wet and dry seasons over 21 months in 2003–2005 to estimate their potential for sustainable exploitation of ornamental fishes. In total, 35 species of fish representing 22 genera and 14 families were captured. By biotope, fish populations per 20 m averaged 528 ± 318.5 fish (8.0 ± 3.02 species) in runs, 86 ± 60.9 fish (2.4 ± 1.06 species) in riffles and 819 ± 480.0 fish (7.8 ± 3.15 species) in pools. Riffles contained significantly fewer individuals and species than either runs or pools. Shannon's index was similar for runs and pools, averaging 1.646 ± 0.429 and 1.548 ± 0.345, respectively, but differed significantly for riffles, averaging 0.652 ± 0.473. There were no significant differences in number of individual fish, number of species or Shannon's index among stream order or season, reflecting the stability of these ecosystems throughout the year. Regression of number of fish per 20 linear m of stream, number of species and Shannon's index against a subjective scale related to stream degradation was significant. In particular, the polluted Limbe River sites had significantly fewer individual fish, fewer species and a lower Shannon index across all biotopes than other sites. Fishing efficiency of local gears was estimated at 27% for easily captured species and 14% for the more difficult ones, and could be used to make relative estimates of fish abundance as a means of monitoring changes in fish abundance. Although species diversity in south-western Cameroon was high, typical of tropical streams globally, total abundance was low, and therefore it is unlikely that a profitable ornamental fish trade could be sustained on the basis of fish captured exclusively from the wild.     

Diet composition of the African manatee: Spatial and temporal variation within the Sanaga River Watershed,Cameroon

The present study aimed to investigate the diet of African manatees in Cameroon to better inform conservation decisions within protected areas. A large knowledge gap on diet and seasonal changes in forage availability limits the ability to develop informed local management plans for the African manatee in much of its range. This research took place in the Sanaga River Watershed, which includes two protected areas in the Littoral Region of Cameroon: the Douala‐Edea National Park and the Lake Ossa Wildlife Reserve. We analyzed 113 manatee fecal samples and surveyed shoreline emergent and submerged vegetation within the Sanaga River Watershed. We used microhistological analyses to determine the relative contribution of each plant species to African manatee diets and compared across locations and across seasons (wet vs. dry season). We found that the shoreline vegetation is diverse with over 160 plant species, unevenly distributed across space and season, and dominated by emergent vegetation mostly represented by the antelope grass (Echinochloa pyramidalis). We recorded a total of 36 plant species from fecal samples with a spatial and temporal distribution mostly reflecting that of the corresponding shoreline vegetation. African manatees appear to be primarily opportunistically feeding on available vegetation across the seasons and habitat. This work documents the current, but changing, state of plant availability in the Sanaga River Watershed and reports the African manatee diet in Cameroon for the first time. This information can play a critical role in successfully managing the species and these protected areas. If we wish to protect the African manatee and the aquatic ecosystems within the Sanaga River Watershed, we must understand how forage availability changes over time, especially as its waters become nutrient enriched, eutrophic, and exposed to invasive species of plants in a changing world.     

Synopsis of the genus Mitriostigma (Rubiaceae) with a new monocaulous species from south Cameroon

Mitriostigma monocaule Sonké & Dessein sp. nov., a new Rubiaceae species from south Cameroon is described and illustrated. The novelty is easily separated from the other four Mitriostigma species by its monocaulous growth form, the other species being shrubs, sub-shrubs, or occasionally trees. Another typical character for the species is its supra-axillary inflorescences paired at the nodes. The novelty is related to M. barteri , from which it further differs in the somewhat larger leaves with a more pronounced acumen and a higher number of secondary veins. A first conservation status for the species is given. A synopsis of the genus Mitriostigma with a taxonomic key is also provided.     

Uses, management, and economic potential ofDacryodes edulis (Burseraceae) in the Humid Lowlands of Cameroon

Dacryodes edulis is one of the most preferred tree species by farmers in the humid lowlands of Cameroon. The fruit of the species figures prominently in cross-boundary trade between Cameroon, Nigeria and Gabon. Although there exist empirical data on the volume of trade of the fruit at this level, no data are available at the farm level. A field survey was undertaken to identify uses, management, and farmers’ improvement objectives and to quantify, at the farm-level, the economic potential of the species. The results of the survey indicate thatD. edulis is widely planted and found mainly in tree crop fields and in home gardens. The fruit is highly consumed and traded. The farm-level value of fruit production reaches $US161 a year per grower or collector. The dead branches of the species are used as firewood and its bark is used as medicine. Desired improvement objectives include increased fruit size, good tasting fruit, high yield and reduced time to bearing.     

The Distribution, Status, and Conservation Outlook of the Drill (Mandrillus leucophaeus) in Cameroon

The populations of many endangered species are becoming increasingly fragmented, and accurate, current information on the status of these subpopulations is essential for the design of effective conservation strategies within a human-dominated landscape. The drill (Mandrillus leucophaeus) is one of the most spectacular and endangered primates in Africa, yet up-to-date information on its distribution, population status, and conservation outlook is lacking. Cameroon has been estimated to encompass 80 % of the species’ range. We examined the distribution, population status, and conservation outlook for the drill throughout its historic range in Cameroon. To do this, we divided the historic range of the drill in Cameroon (46,000 km²) into 52 survey units along natural and manmade boundary features. Based on a series of field surveys in 2002–2009, village interviews, analysis of geospatial data, and bibliographical research, we assigned each survey unit a rank of 0–4 for 15 parameters indicative of current situation for drills, habitat suitability, and conservation outlook. We obtained direct evidence for the presence of drills in 16 of the 52 survey units, with those of Ejagham, Korup, Ebo, and Nta Ali receiving the highest index scores. We warn of local extirpations and increased isolation among drill populations due to loss of dispersal corridors, e.g., Douala Edea survey unit. In some cases drills persist in forest fragments within human-dominated landscapes, e.g., Kupe-Manenguba, but the species’ future is probably dependent on effective wildlife management in a handful of isolated strongholds where probability of long-term protection is higher, particularly in Korup National Park, Takamanda National Park, and the proposed Ebo National Park. Pressure from current and proposed large-scale commercial plantations, oil prospecting, logging, and the continual human population growth in this region means that a concerted conservation effort will be needed to safeguard the remaining drill habitat if the species is to survive in Cameroon.     

Diospyros korupensis sp. nov. and Diospyros onanae sp. nov. (Ebenaceae) from Cameroon

Diospyros korupensis Gosline is described as a new species endemic to the Korup National Park in Cameroon and neighbouring areas on the slopes of Mt Cameroon. Diospyros onanae Gosline is described as a new species from the South and Southwest Regions of Cameroon allied to the poorly known D. soyauxii Gürke & K. Schum. ex. Gürke.     

The interaction of Schistosoma haematobium and S. guineensis in Cameroon

Interactions between schistosomes are complex with some different species being able to mate and hybridize. The epidemiology of schistosomiasis in specific areas of South West Cameroon has evolved remarkably over 30 years as a result of hybridization between Schistosoma guineensis and S. haematobium. Morphological and biological data suggest that S. haematobium replaced S. guineensis in areas of Cameroon through introgressive hybridization. Data are reported on the use of single stranded conformational polymorphism (SSCP) analysis of the nuclear ribosomal second internal transcribed spacer (ITS2) of individual schistosomes from hybrid zones of Cameroon. The data show that since 1990 S. haematobium has completely replaced S. guineensis in Loum, with S. haematobium and the recombinants still present in 2000. This study illustrates the complexities of the dynamics between S. haematobium and S. guineensis in South West Cameroon.     

Reversal of breeding season by lowland birds at higher altitudes in western Cameroon

Evidence of breeding during the dry season is given for 31 species of lowland birds in montane and semi-montane areas in western Cameroon. At least 17 of these species are shown to breed in the wet season at lower altitudes in West Africa. This reversal of breeding season may be due to the unusually heavy rainfall and high humidities which cause temperatures to decrease more rapidly with altitude than on mountains with drier climates. Low temperatures and heavy rainfall during the wet season prevent almost all montane species from breeding then, and affect similarly the lowland birds whose ranges overlap with those of montane birds. Breeding seasons of some lowland species in Cameroon have previously been considered prolonged, but separation of breeding records by altitude reveals clear seasonality.     

A new species of Afrothismia (Burmanniaceae) from Cameroon

Afrothismia hydra, a new species of Burmanniaceae (tribe Thismieae) from South west Cameroon is decribed, illustrated and compared with related taxa.     

A reconsideration of the Lower Guinean species of Sericanthe (Rubiaceae,Coffeeae), with four new species from Cameroon and Gabon

The genus Sericanthe was established and its species were revised 30 years ago by one of the authors. Intensive recent botanical collecting in Lower Guinea (mainly southern Cameroon, Equatorial Guinea and Gabon) has made a reconsideration of species in this area necessary. Revision of the newly collected Lower Guinean herbarium specimens of Sericanthe (twice as many as were available at the time of the first revision) has brought four new species to light, namely S. gabonensis and S. mpassa from Gabon, S. lowryana from Cameroon and S. rabia from Cameroon and Gabon. Distributional data are much augmented, and distributional maps of all species from the area are provided. Four species were reported to be newly recorded for at least one country. The occurrence of the novelties in the main diversity centre of the genus is discussed in the context of the chorology of the entire genus Sericanthe. A first estimation of the conservation status for the new species is given. A synopsis of the genus Sericanthe in Lower Guinea with a taxonomic key is provided. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 530–554.     

Comparative avian biodiversity of five mountains in northern Cameroon and Bioko

Larison, B., Smith, T.B., Fotso, R. & McNiven, D. 2000. Comparative avian biodiversity of five mountains in northem Cameroon and Bioko. Ostrich 71 (1 & 2): 269–276.

Endemism among birds is widespread in the montane forests of western Cameroon and the Gulf of Guinea. The region includes some of the rarest and most threatened species in Africa. We conducted avian surveys of four previously unsurveyed montane sites in northern Cameroon, including Mt. Ngang-Ha, Hoséré Vokré, Tchabal Gandaba, and Tchabal Mbabo, as well as the northern slope of Caldera de Luba on the island of Bioko, Equatorial Guinea. We report here on avian species richness and relative abundance, and evaluate the conservation potential of each site based on avifaunal richness. The montane forest on both Tchabal Mbabo and Caldera de Luba is extensive, while on the other mountains, the vegetation is not characteristic of montane forest, and consists primarily of small gallery forests embedded in savanna. Tchabal Mbabo and Caldera de Luba had the greatest species richness and abundance of montane birds, while Tchabal Gandaba had the greatest overall avian species richness and abundance. Few montane species were noted on Mt. Ngang-Ha and Hosere Vokre, and avian abundance was quite low on both mountains. Of the mountains surveyed, Tchabal Mbabo and Caldera de Luba exhibit the greatest potential for conservation based on extent of montane forest, and montane species richness and abundance.     

The Influence of Farmers’ Strategies on Local Practices,Knowledge, and Varietal Diversity of the Safou Tree (Dacryodes edulis) in Western Cameroon

Economic Botany - Highly valued for its edible fruits, the safou tree, Dacryodes edulis, is a major component of farming systems in Central Africa. In Cameroon, the species has drawn much attention...