The territorial system of the kob antelope (Kobus kob kob) in the Comoé National Park, Côte d'Ivoire

The territorial system of kob antelopes in the Comoé National Park, Côte d'Ivoire, was studied from March 1993 until April 1997. Whereas size and shape of territories remained constant between 1993 and 1994, the number of territories decreased from 1994 onwards. A decline of the population density probably led to the decline in territory numbers and also to variations in size and shape of the remaining territories. The decline of kob numbers is the result of heavy poaching in the study area. Whereas a lekking system was present in the study area prior to 1975 when the population density was approximately 14.4 kobs/km², males switched to the resource defence territorial system present today after the population density decreased to 12.5/km² in 1993 and finally to 2.3/km² in 1997. Compared to other research areas with higher population densities, territories in the Comoé National Park are larger, almost all adult males are capable to defend a territory, fights over territories are rare and loss of territory tenureship is almost exclusively due to the death of the territorial male. We suggest that those differences can all be related to the low population density in the study area.     

Morphological and allozyme variation in a collection of Cucumeropsis mannii Naudin (Cucurbitaceae) from Côte d'Ivoire

To set up a rational collecting strategy for germplasm of the edible-seeded cucurbit Cucumeropsis mannii, a study was conducted using 24 morphological and seven putative enzyme markers to determine the intra-specific variability from 16 and 22 accessions (representing three cultivars), respectively. The analysis of variance, showed a significant difference between the three cultivars. Principal component analysis pointed out a variation among individuals, mainly on the basis of flower, fruit, and seed size. Dendrogram with UPGMA method allowed clustering of the cultivars. Genetic diversity indices estimated equalled: 9.96% for the proportion of polymorphic loci (P), 1.10 for the number of alleles (A) and 0.023 for observed heterozygosity (H_o). The level of the within accessions genetic diversity (H_S = 0.078) was higher than among accessions (D_ST = 0.042). Nei's genetic distances between the three cultivars were also low (0.079–0.147), indicating a high degree of similarity of the analysed cultivars.     

Resource availability and distribution patterns, indicators of competition between Macrotermes bellicosus and other macro-detritivores in the Comoé National Park, Côte d'Ivoire

Interspecific competition has rarely been demonstrated in field studies. For it to occur a resource must be in limited supply and potential competitors must be concurrently active in time and space. We studied the availability of plant litter during the course of the year and the activity and distribution of macro‐detritivores (termites, diplopods and earthworms) in two habitats in a Guinea savanna (Côte d'Ivoire), to test whether interspecific competition might be important. Plant litter was limited during the rainy season in the savanna, but was never limited in the gallery forest. The termite Macrotermes bellicosus, the dominant macro‐detritivore in this area, and other detritivorous termites (e.g. Microtermes spp., Ancistrotermes spp., Odontotermes spp.) were active all year round with a peak during the rainy season, when diplopods and earthworms were also active. In the savanna at the beginning of the rainy season when food became limiting, other detritivorous termite species were more active in the absence of M. bellicosus than in its presence. This complementary activity pattern of M. bellicosus and other termites indicates that interspecific competition among detritivorous termites may be occurring. However, the spatio‐temporal distribution of diplopods and earthworms suggests that interspecific competition with M. bellicosus is of minor importance.     

The development of plant-parasitic nematode infestations on micro-propagated banana plants following field control measures in Côte d'Ivoire

Of the weeds that were found in banana production areas, only Asystasia gangetica was parasitised by Radopholus similis; Helicotylenchus multicinctus and Hoplolaimus pararobustus were able to parasitise all weed species. Field trials were carried out in Cote d'Ivoire to assess the potential for using nematode-free micro-propagated banana plants following cultural and chemical methods for nematode control. Banana (Musa acuminata) cv. Poyo was examined for nematodes after weed fallow, flooding and chemical treatment. Before replanting bananas, nematode assays showed that: i) all nematode species declined but were not eliminated after a 1,3-dichloropropene soil treatment; ii) H. multicinctus, H. pararobustus and Cephalenchus emarginatus were still present after either a 2-year weed fallow (dominated by Chromolaena odorata or Asystasia gangetica) or a 10-week flooding; iii) R. similis did not persist after fallowing or flooding. All nematode species were found in plots treated with 1,3-dichloropropene and that had been planted with bullheads, suckers or nematode-free micropropagated plants. After both fallow and flooding, R. similis was reintroduced on infested planting materials (bullheads and suckers) even when they were pre-treated with a nematicide. When fallow and flooded plots were planted with nematode-free materials (vitro-plants), R. similis did not appear in the roots for two vegetative cycles. The other species, still present in the soil, invaded the roots and increased slowly in numbers. These results were confirmed in commercial banana plantations.     

Preliminary estimates of the population parameters of major fish species in Lake Ayamé I (Bia basin; Côte d'Ivoire)

Length frequency data collected from artisanal fisheries in Lake Ayamé I (Côte d'Ivoire) from August 2004 to 2005 were analysed with F isat software using the E lefan package to estimate the population parameters of 11 fish species. Asymptotic values for total length ( L∞ ) ranged from 20.5 cm for Brycinus imberi to 78 cm for Mormyrops anguilloides . Growth rates ( k ) varied from 0.24 year⁻¹ for Chrysichthys nigrodigitatus to 0.57 year⁻¹ for Hemichromis fasciatus . The growth performance estimates were close to the values found by others authors and reported in FishBase 2008. Fishing mortality ( F ) and exploitation rate ( E ) were found to be below optimum levels of exploitation for most fish species. Recruitment was noted as year–round and bimodal for most studied populations. The data sets were limited in most cases, thus this study provides preliminary population parameters only, but for species for which information is scarce. For application in stock assessment, the growth parameters and especially the natural mortality data require further confirmation.     

Brands as masks: public secrecy and the counterfeit in Côte d'Ivoire

Rethinking Simmel's comparison of secrecy and adornment, I consider the ways in which brands function much like masking practices, concealing even as they reveal, using the visible to hide/signify the invisible. The classic masking scenario is one in which men wear masks and claim to be powerful ancestral spirits, keeping the fact of their performance a secret from women and uninitiated boys. However, the secrecy is ambiguous, for women give signs of knowing and men seem to believe in the spirits they pretend to be only pretending to be. In Côte d'Ivoire, where masks are a symbol of national identity, consumption focuses around displaying supposedly authentic name brand labels. Urban Ivoirians call this display of wealth and consumption ‘bluffing’, exposing the artifice of their supposed affluence. Still, the success of their performance depends on the authenticity of expensive European and American brands, in a market where most of what is available is counterfeit. Underneath the public secret of their performative display lies the deeper secret that they remain uncertain of the legitimacy of their purchases. Masks and brands both metaphorically delineate a metonymic though invisible connection to authentic power, but the secrecy of what lies beneath the masked performance provides an unstable ambiguity in which it is always possible that the surface is that which it represents. Brands always contain this instability between appearance and the genuine, for all are ultimately copies whose uncertain authenticity we cover up with public secrecy.     

An experimental study of the effects of nutrient supply and Chaoborus predation on zooplankton communities of a shallow tropical reservoir (Lake Brobo, Côte d'Ivoire)

1. Based on two mesocosm experiments and 10 in vitro predation experiments, this work aimed to evaluate the impact of nutrient supply and Chaoborus predation on the structure of the zooplankton community in a small reservoir in Côte d'Ivoire. 2. During the first mesocosm experiment (M1), P enrichment had no effect on phytoplankton biomass (chlorophyll a) but significantly increased the biomass of some herbivorous zooplankton species (Filinia sp, Ceriodaphnia affinis). During the second experiment (M2), N and P enrichment greatly increased phytoplankton biomass, rotifers and cladocerans (C. affinis, C. cornuta, Moina micrura and Diaphanosoma excisum). In both experiments, nutrient addition had a negative impact on cyclopoid copepods. 3. Larger zooplankton, such as cladocerans or copepodites and adults of Thermocyclops sp., were significantly reduced in enclosures with Chaoborus in both mesocosm experiments, whereas there was no significant reduction of rotifers and copepod nauplii. This selective predation by Chaoborus shaped the zooplankton community and modified its size structure. In addition, a significant Chaoborus effect on chlorophyll a was shown in both experiments. 4. The preference of Chaoborus for larger prey was confirmed in the predation experiments. Cladocerans D. excisum and M. micrura were the most selected prey. Rotifer abundance was not significantly reduced in any of the 10 experiments performed. 5. In conclusion, both bottom‐up and top‐down factors may exert a structuring control on the zooplankton community. Nutrients favoured more strictly herbivorous taxa and disadvantaged the cyclopoid copepods. Chaoborus predation had a strong direct negative impact on larger crustaceans, favoured small herbivores (rotifer, nauplii) and seemed to cascade down to phytoplankton.     

Field application of the polymerase chain reaction (PCR) to the detection and characterization of trypanosomes in Glossina longipalpis (Diptera: Glossinidae) in Côte d'Ivoire

The Polymerase Chain Reaction (PCR) technique was used for the identification of natural trypanosome infections in Glossina longipalpis (Diptera: Glossinidae) in Côte d'Ivoire. A total number of 139 flies were examined microscopically for the presence of trypanosomes. Out of them 50 were detected positive and were subsequently prepared for the PCR using primers specific for Trypanosoma (Nannomonas) congolense of Savannah, Riverine-Forest, Kilifi, and Tsavo types, T. (N.) simiae, T. (Duttonella) vivax and Trypanozoon. Almost 90% of the infections detected by the PCR were attributed to Nannomonas, especially T. congolense Savannah and Riverine-Forest types, with many infections in which both of these two types were present T. simiae and T. vivax were also detected in some flies. The sequence specificity of the PCR products was confirmed by hybridization with parasite-type specific DNA probes. Differences between parasitological and PCR results are discussed.     

Skeletal and dental growth and development in chimpanzees of the Taï National Park, Côte D'Ivoire

An extraordinary collection of 22 immature skeletons from Taï National Park, Côte d'Ivoire, has provided a rare opportunity to establish the timing of dental eruption and its correlation with skeletal fusion and morphometrics in wild chimpanzees of known chronological ages. Comparison of the immature Taï chimpanzees Pan troglodytes verus with adults from the same population show that sex differences in skeletal maturation apparently appear during the Juvenile II stage, about age 8. A few skeletons from other chimpanzee field sites conform to the dental and skeletal growth in Taï chimpanzees. The tempo of wild chimpanzee growth contrasts sharply with the rate demonstrated for captive individuals. Captive chimpanzees may mature as much as 3 years earlier. The ability to link physical development with field observations of immature chimpanzees increases our understanding of their life-history stages. These data provide an improved dataset for comparing the rates of growth among chimpanzees, Homo sapiens and fossil hominids.     

Dental wear among cercopithecid monkeys of the Taï forest,Côte d'Ivoire

Studies of dental macrowear can be useful for understanding masticatory and ingestive behavior, life history, and for inferring dietary information from the skeletal material of extinct and extant primates. Such studies to date have tended to focus on one or two teeth, potentially missing information that can be garnered through examination of wear patterns across the tooth row. Our study measured macrowear in the postcanine teeth of three sympatric cercopithecid species from the Taï Forest, Côte d'Ivoire (Cercocebus atys, Procolobus badius, and Colobus polykomos), whose diets have been well‐described. Inter‐specific analyses suggest that different diets and ingestive behaviors are characterized by different patterns of wear across the molar row, with Cercocebus atys emphasizing tooth use near P₄‐M₁, P. badius emphasizing a large amount of tooth use near M₂‐M₃, and Colobus polykomos exhibiting wear more evenly across the postcanine teeth. Information regarding differential tooth use across the molar row may be more informative than macrowear analysis of isolated teeth for making inferences about primate feeding behavior. Am J Phys Anthropol 150:655–665, 2013. © 2013 Wiley Periodicals, Inc.     

Factors Influencing Tree Phenology in Taï National Park,Côte d'Ivoire1

Entrained phenology patterns of tropical trees are expected to be sensitive to short‐term fluctuations in typical rainfall and temperature. We examined 47 mo of data on the flowering, fruiting, and new leaf phenology for 797 trees from 38 species in the Taï National Park, Côte d'Ivoire. We determined the timing of the phenology cycles in relation to seasonal rainfall, temperature, and solar radiation. Regression analysis was used to examine how variations in rainfall and temperature influenced deviations in the peaks and troughs of phenology cycles. We also investigated whether populations that fruit during periods of community‐wide fruit scarcity were those populations with relatively long‐ or short‐fruiting duration. Flower, fruit, and leaf‐flushing phenophases all exhibited 12‐mo cycles. The broad peak in flowering began with the northward zenithal passing in April and ended with the southward zenithal passing in September. Fruiting peaks occurred in the long dry season, and leaf flushing peaked in the long dry season but continued into the wet season. Deviations from phenology cycles were largely attributable to short‐term fluctuations in rainfall and/or temperature. Fruiting durations of species were related to the mean diameter at breast height. Species with long‐ and short‐fruiting durations contributed equally to fruit abundance during periods of community‐wide fruit scarcity.     

Impact of Commercial Hunting on Monkey Populations in the Taï region,Côte d'Ivoire1

We studied the impact of hunting on monkey species in the Taï National Park and adjacent forests in Côte d'Ivoire. The average wild meat consumption per capita per year was assessed from market surveys and interviews. We determined that the amount of primate wild meat being extracted in the Taï National Park and surrounding forests was 249 t in 1999. Hunting pressure was the highest on the larger primate species such as red colobus, Procolobus badius, black and white colobus, Colobus polykomos, and the sooty mangabey, Cercocebus torquatus atys. Estimates of population densities were based on line transect surveys. The maximum annual production of each species was calculated using the Robinson and Redford model (1991) and assuming unhunted conditions. Comparing current harvest levels with the maximum sustainable yield suggests that harvest of red colobus monkeys (Procolobus badius) is sustainable, whereas current off‐take of the black and white colobus (Colobus polykomos), the sooty mangabey (Cercocebus atys), diana monkeys (Cercopithecus diana), and Campbell's monkeys (Cercopithecus campbelli) exceeds sustainability by up to three times.     

Feeding habits of the mochokid Synodontis punctifer Daget, 1964, in the Bandama River,Côte d'Ivoire

The feeding habits of Synodontis punctifer were investigated in the basin of the Bandama River. Fish specimens were collected using gill nets in the rainy season (May–July 2009) and in the dry season (November 2008 to March 2009 and August 2009). In this article, the importance of the different prey types was assessed using the corrected occurrence and weight percentage. These values were used to calculate the index of preponderance for each taxonomic category. One hundred and ten specimens of S. punctifer were examined, nine stomachs were found empty (8.18%). A total of 39 different prey species belonging to seven major groups Insects, Crustacea, Rotifera, Molluscs, Other invertebrates, Other organisms and Macrophytes were identified in the stomach contents. The results showed that Macrophytes were the primary food item and Insects the secondary prey item. Other preys were recorded occasionally. At the rainy season, the main foods of S. punctifer were Macrophytes and during the dry season this species ate Insects and Macrophytes. The food composition varied between localities. In the riverine localities, specimen fed on 38 prey types. Twenty‐seven prey categories were consumed in the lacustrine. In terms of diet overlap, Schoener coefficient values were above the 0.6 limit (α = 0.99), indicating some high overlap.     

Inventory and abundance of mealybug species in immature and mature cocoa farms in Côte d'Ivoire

From 2013 to 2018, surveys were conducted in counties not previously surveyed in order to determine species of mealybugs present in the cocoa orchard in Côte d'Ivoire as well as their abundance according to the age of cocoa trees. Immature and mature cocoa trees were inspected to hand‐height in 5 and 29 counties infected with Cacao swollen shoot virus (CSSV). In each cocoa farm, mealybugs were searched for on fruits, leaves, flowers, twigs and trunks. Mealybug species were identified, and colonies were counted. Five mealybug species were identified on immature cocoa trees: Ferrisia virgata, Formicococcus njalensis, Planococcus citri, Planococcus kenyae and Pseudococcus longispinus. In addition to these species, four species, Dysmicoccus brevipes, Maconellicoccus hirsutus, Phenacoccus hargreavesi and Pseudococcus jackbeardsleyi were identified on mature cocoa trees. On immature cocoa trees, Fo. Njalensis, Pl. citri and Ps. longispinus comprised were, respectively, 35%, 33% and 19% of colonies, respectively. On mature cocoa trees, Fo. Njalensis and Pl. citri comprised 63.2% and 21.0%, and others species 15.8%. Nevertheless, the abundance of mealybug species varied according to the age of cocoa trees. The preferred organs of mealybugs were pods (74.1%) followed by twigs (13.4%) and flowers (7.4%). Previously, the mealybug Paracoccus burnerae (Brain) was found on Theobroma cacao, which is the first record for this species in Côte d'Ivoire and on this host‐plant.     

Distribution of twelve moist forest canopy tree species in Liberia and Côte d'Ivoire: response curves to a climatic gradient

Abstract. The occurrence and abundance of 12 canopy tree species from the moist tropical forests of West Africa have been studied in relation to a climatic gradient. We focused on environmental factors related to water availability: annual amount of rainfall, the length of the dry season, and cumulative water deficit. Species occurrence and abundance data are used for 39 forest sites in Liberia and southwest Côte d'Ivoire. Species responses are modelled using a set of five increasingly complex models, ranging from a no-trend model to a skewed bell-shaped response curve. The study species show different distribution patterns. Most of them suggest a close relationship to climatic conditions. Fitting of species occurrence data to each of the three climatic factors results in most cases in simple models. In only one out of 36 cases a bell-shaped response curve is needed to describe the data. Four of the 12 species show no response to the climatic factors when only occurrence is evaluated. When abundance data are used, in 33 of the 36 cases significant response models are found. In general these are much more complex than in the cases of species occurrence data: in 10 of the 36 cases a bell-shaped response model is found to describe the data best. This is in contrast with the widespread belief that species response curves are bell-shaped: within the forest zone in the area studied this is not generally the case. The importance of the three climatic factors for the distribution of the species is evaluated: for four species mean annual rainfall is the most important variable, for four species the length of the dry period, and for one species cumulative water deficit. Consequently, the assumption that mean annual rainfall is the most important factor determining tree species distribution in West African forests is not correct. Species response models to climatic factors show where species have their geographical optima. Implications for forest management are briefly discussed.