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The giant anteater ( Myrmecophaga tridactyla) is generally considered a savannah inhabitant; little information exists on populations in forested areas as much as on most other aspects of its ecology. The aim of this study was to determine the ecological value of timber plantations to the species and its requirements of anthropogenically used and converted habitats. We investigated habitat use and distribution patterns of giant anteaters in Acacia mangium plantations in a northern Brazilian savannah biotope. Road counts were conducted to estimate anteater densities in two different habitats. Anteaters showed strong diurnal foraging activities in the plantations, and their densities were substantially higher there than in the surrounding savannah [plantations: 2.9 individuals (ind.)/km2; savannah: 0.1 ind./km2], with concentrations of up to 13.4 ind./km2. Although fundamental changes of anteater densities occurred on small scales in the plantations, no connection between anteater distribution and plantation management practices could be found. Food availability in Acacia plantations and cover from both extreme temperatures and potential predators probably make these forested areas well suited for giant anteaters. We conclude that conditions comparatively beneficial to the anteater can be found in natural forests but usually not in plantations of other exotic timber species. This needs to be incorporated in forestry management plans aiming at supporting this charismatic animal. [ABSTRACT FROM AUTHOR]

We studied the social system and time budget of kob antelopes in the Comoé National Park, Côte d'Ivoire from March 1993 till May 1998, a population that is suffering from heavy over-hunting, to assess information about the effects of population decrease and its relevance for conservation of this antelope population. Single animals accounted for the majority of observed kob antelopes. Time allocated to certain behavioural traits depended on group size, with animals in smaller units spending less time on behaviours sensitive to predation risk. Single animals allocated far less time to ruminating and feeding being more vigilant and walking more. Groups were highly fluid and associations between individuals could be predicted by home-range overlap among females but not for female/male associations where association indices might be influenced by reproductive aims. Frequency of social groupings did not change compared with earlier studies when population density was much higher. However, compared with these studies maximum group size decreased, and smaller groups became more abundant. The observed effect of group size on the time budget of kob antelopes in combination with a steady decrease in group size because of reduction in population size might have a severe impact on the long-term persistence of the studied kob population due to anticipated aggravated predation effects. As males form the majority of single animals, putting them on higher predation risk, number of males decreases more rapidly than the number of females, which might eventually lead to a collapse of the kob population. Résumé Nous avons étudié le système social et l'emploi du temps des antilopes cobes dans le Parc National de Comoé, en Côte d'Ivoire, entre mars 1993 et mai 1995. C'est une population qui souffre d'une grave sur-chasse, et nous voulions évaluer les informations sur les effets de la diminution de la population et leur pertinence par rapport à la conservation de cette population d'antilopes. La majorité des observations de cobes concernaient des animaux solitaires. Le temps consacréà différents types de comportement dépendait de la taille du groupe, les animaux faisant partie des plus petits groupes allouant moins de temps à des comportements sensibles au risque de prédation. Les animaux isolés passaient beaucoup moins de temps à ruminer et à se nourrir car ils étaient plus vigilants et se déplaçaient davantage. Les groupes étaient très fluides, et on pouvait prévoir les associations entre individus femelles par le recouvrement de l'occupation spatiale des femelles, mais pour les associations mâles-femelles, les indices peuvent être influencés par des buts reproducteurs. La fréquence des regroupements sociaux n'a pas changé par rapport aux études antérieures, quand la densité de la population était beaucoup plus élevée. Cependant, par rapport à ces études, la taille maximale du groupe a diminué, et les plus petits groupes sont plus abondants. L'effet observé de la taille du groupe sur le budget temporel des antilopes cobes, combinéà la diminution très nette de la taille des groupes due à la réduction de la taille de la population, pourrait avoir un impact sévère sur la persistance à long terme de la population étudiée car on peut s'attendre à des effets plus graves de la prédation. Comme les mâles forment la majorité des individus solitaires, ce qui les met plus en danger face aux prédateurs, le nombre de mâles diminue plus vite que celui des femelles, ce qui pourrait conduire à l'effondrement de la population de cobes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract The kob (Kobus kob kob ) population studied in the Comoé National Park, Ivory Coast, suffered unsustainable losses to poaching before and during the investigation. This in turn did not only lead to low densities but also changed the population composition, resulting in a strong female bias in all age classes except juveniles. The relative rarity of adult males probably had negative effects on the population recruitment. Although mating occurred throughout the year and birth intervals were short, at least in some females, annual birth-rate was low compared to earlier studies in the same area. Effective conservation measures are urgently needed to ensure the future existence of the studied population. [ABSTRACT FROM AUTHOR]

Abstract Spatial and temporal habitat use of kob antelopes (Kobus kob kob) have been investigated in the Comoé National Park (Ivory Coast, West Africa) by use of radio telemetry. A total of 23 kob were equipped with radio collars and radio tracked for up to 15 months. Home ranges of males were smaller and those of females larger than expected from theoretical models. Adult males used smaller areas than adult females and did not show seasonal home range shifts. Daily distances travelled did not differ between sexes. Kob walked less during the night than by day and covered shorter distances in the wet season. Whereas an increase in home range overlap between females resulted in higher rates of association among individuals, association of adults of mixed sexes was not correlated with the degree of home range overlap. Territorial behaviour of males and predator avoidance by females are suggested to explain the sex-specific differences in home range size of adults and the deviation from the predicted sizes. Predator avoidance is presumed as the main reason for the reduced walking distances at night as well as in the wet season. Reproductive behaviour and feeding ecology are assumed to determine the degree of association of conspecifics. [ABSTRACT FROM AUTHOR]

Primate seed dispersal in South African forests and its potential benefit to forest plants has not been extensively investigated. South African forests are inhabited by only one exclusively forest-dwelling, large-bodied,diurnal, frugivorous primate, the samangomonkey (Cercopithecus mitis). Our study presents first insights into seed dispersal by samango monkeys in anAfromontane forest in their northernmost SouthAfrican distribution.Through focal animal sampling we found that samango monkeys were predominantly frugivorous (72% of observed feeding time), consuming fruits of 25 plant species and dispersing the seeds of 13 (52%) of them through defecation, carrying in cheek pouches and spitting and dropping. The overall ratio of seed predation was relatively low (16%). Although our study spanned the wet season only, our findings demonstrate that samango monkeys may be potentially important seed dispersers for certain plant species (Ficus spp. and Searsia chirindensis making up 44% of the diet) in this part of their range. [ABSTRACT FROM AUTHOR]

This paper reports the results of the first study on secondary seed removal of seeds dispersed by Sykes' monkeys ( Cercopithecus albogularis) using camera traps in Africa. Patterns of primary seed dispersal are often superimposed by secondary conveyance, emphasising the need to study these secondary processes carefully. As the agents and mechanisms of seed dispersal are often concealed, being carried out by cryptic or nocturnal animals in dense vegetation, camera trapping was deemed a viable means to investigate secondary removal of seeds disseminated by C. albogularis in the Western Soutpansberg, South Africa. Camera traps were established at preferred feeding trees of the focal Sykes' monkey group to identify animal species that remove seeds and fruits spat and dropped to the forest floor and seed removal observations were carried out. This method proved to be effective in identifying seed removers and also allowed to get indications about the quantities of seeds removed. Ten animal species were recorded visiting the trees, of which eight were observed removing seeds and fruits. Overall seed and fruit removal rates were high, indicating that the foraging behaviour of C. albogularis attracts many terrestrial frugivores. [ABSTRACT FROM AUTHOR]

Long-term wildlife monitoring programs are typically listed as a fundamental component of protected area (PA) management. Unfortunately, few PAs have wildlife population monitoring information available over extended periods of time, particularly in the many forested PAs throughout tropical Africa. Taï National Park in south-western Côte d'Ivoire is one of these few. Regular wildlife monitoring based on transect dung count sampling and direct observations began as early as 1977 in five sections of the park. In this paper, we present comparative descriptive results from two periods, 1977-1983 and 1995-2004. Several large mammal species, such as forest elephants and bongos, have experienced dramatic population declines over this time period, with some decline rates as high as 91%. Other species, such as duikers and leopards, seem to have better resisted the primary cause of these observed declines, hunting. In addition, we found that day counts delivered mostly significantly lower density estimates for several of the monitored species than night counts, which shows the importance of carefully interpreting the estimates from other studies. The continuation of wildlife monitoring will provide further insight into the efficiency of implemented park management with regard to the observed population changes. [ABSTRACT FROM AUTHOR]

Abstract: Regulation of proteolytic cleavage of the amyloid precursor protein by the aspartic protease BACE may occur by alternative splicing and the generation of enzymatically inactive forms. In fact, the presence of exonic donor and acceptor sites for intron 3 generates the two deficient variants BACE457 and BACE476. In HEK293 cells, when introns are inserted separately in the BACE cDNA, we found that whilst introns 2 and 4 are efficiently spliced out, intron 3 is not removed. On the other hand, splicing to wild-type BACE is restored when intron 3 is flanked by the two other introns. The presence of all three introns also leads to alternative splicing of intron 3 and the generation of BACE476. In contrast, BACE457 expression takes place only after mutating the donor splice site of intron 3, indicating that additional regulatory elements are necessary for the use of the splicing site within exon 4. Overall, our data demonstrate that a complex splicing of intron 3 regulates the maturation of the BACE mRNA. This appears orchestrated by domains present in the exons and introns flanking intron 3. Excessive BACE activity is a risk factor for Alzheimer’s disease, therefore this complex regulation might guarantee low neuronal BACE activity and disease prevention. [Copyright &y& Elsevier]

The distribution and relative abundance of the common hippo (Hippopotamus amphibius) and the pygmy hippo (Hexaprotodon liberiensis) was studied in the Ivory Coast between 1978 and 1986 by questionnaire survey, interviews, local field investigations and aerial censuses. In addition, the size of the pygmy hippo population in the Tai Forest area was monitored between 1995 and 2001. At the time of the initial study, the common hippo inhabited the Sassandra, Bandama and Comoé rivers, but was abundant only in the Upper Comoé. The pygmy hippo was restricted to the Guinean Forest zone between 7°25'N (Tiapleu Forest Reserve (Forêts Classée)) in the north and 4°18'W (estuary of the Agnebi River) in the east, where it was abundant in undisturbed rainforest areas. Population data are presented from the Comoé, Tai and Azagny national parks where the ecology of both species was studied in greater detail. The total population of the common hippopotamus was estimated at about 1100 animals in 1978-1984, of which at least 70% concentrated during the dry season in the Upper Comoé, Leraba and Iringou rivers. The average dry-season population density in the Comoé varied at that time between three and four animals per river kilometre, in groups of five to six, but had dropped to one to two per kilometre in 2002. During the rainy season hippos disperse upstream into smaller tributaries and downstream as far as the coast. As the forest zone is modified by forestry and agriculture, small herds of common hippos have become resident and in some localities are sympatric with the pygmy hippo. Pygmy hippos are solitary animals, confined to home-ranges of 50-150 ha. In optimal habitat their population density can be as high as seven animals/km², averaging about three animals/km² over larger areas of undisturbed rainforest. At present, however, hunting pressure has reduced population densities to 0.8-2.5 animals/km² even in... [ABSTRACT FROM AUTHOR]