Sélection de cultivars de riz pluvial obtenus à partir de croisements avec la variété B22

Les variétés de riz pluvial diffusées en moyenne altitude au Lac Alaotra ou dans le Moyen Ouest, présentent un rendement limité lorsque les conditions culturales sont intensifiées (verse). Le cultivar B22 le plus utilisé apparaît en outre sensible à la pyriculariose du cou. Des croisements de variétés poly - aptitudes avec B22 ont été réalisés et sélectionnés au Brésil, puis introduits à Madagascar en 2006. Après multiplication, ils ont été comparés aux témoins B22 et FOFIFA 154 en divers milieux représentatifs du Lac Alaotra (sols de tanety ferrallitiques, sols riches de baiboho ou rizière) ou au Moyen Ouest. Ce matériel végétal s'avère très performant avec des productions de paddy supérieures à 6 t/ha en SCV, même avec minimum d'intrants. (Résumé d'auteur

Spatial distribution and period of activity of the forest elephant (Loxodonta africana cyclotis) at Taï National Park, south western Côte d'Ivoire

Objective: This study aims at determining the spatial distribution and  period of activities of the forest elephant (Loxodonta africana cyclotis) at Taï National Park (TNP) to contribute to its conservation.Methodology and results: Observations of elephants at different locations and time periods were recorded by using 87 camera traps with date and time-stamped settings. Cameras were installed following a systematic placement approach, and their geographic coordinates were recorded using a GPS. After 120 days of trapping, we observed a high concentration of activities in the southern areas of the park. For the period of activities, we noted that observations of unit individuals were recurrent during the day while those of elephant groups were more important at night.Conclusion and application of the results: The south of the park where  there is a large distribution of elephants would be more favourable to these animals. The small number and remoteness of large cities on the periphery of this area of the park could explain that pattern. The distribution and activity period information is useful for park surveillance by rangers. In addition, further studies are needed for a better explanation on the distribution pattern of elephants at TNP.Key words: Taï National Park, elephant, camera traps, distribution, activity period

Les Facteurs de Risques de la Modernisation de l’agriculture a Base de Pesticides dans la SousPrefecture de Tapeguia

The study has conducted in the sub-prefecture of Tapéguia (Issia department in Côte d'Ivoire). It is part of the context of modernization of pesticide-based agriculture. Our goal is to identify the socio-sanitary and agroecological risk factors associated with the use of pesticides. The data are collected from 110 households of farmers chosen arbitrarily in the village lands of Tapeguia, Gazibouo, Madiassocra and Zadioha (Gabia subprefecture), using a questionnaire made from the Sphinx software which has served for the analysis of quantitative data. The results of the study showed the widespread use of pesticides in the sub-prefecture of Tapeguia. The use of pesticides is influenced by various socioeconomic and agroecological motivations. However, degradation risk factors for agroecosystems result in overexploitation of fallow land, unregulated pesticide use by farmers who ignore or do not consider the risks of intoxication for agroecosystems. Added to there are the dependence of producers on agricultural pesticides and the health problems of farmers (1.8% to 14.5% experience poisoning) due to ignorance or lack of consideration of risks and lack of knowledge training of farmers on the requirements of pesticide use. L’étude a été réalisée dans la sous-préfecture de Tapéguia (département d’Issia en Côte d’Ivoire). Elle s’inscrit dans le contexte de modernisation de l’agriculture à base de pesticides. Notre objectif consiste à identifier les facteurs à risques socio-sanitaires et agroécologiques liés à l’utilisation des pesticides. Les données sont collectées auprès de 110 ménages d’agriculteurs choisis arbitrairement dans les terroirs villageois de Tapéguia, de Gazibouo, Madiassocra et Zadioha (sous-préfecture de Gabia), à l’aide d’un questionnaire réalisé à partir du logiciel Sphinx qui a servi pour l’analyse des données quantitatives. Les résultats de l’étude ont montré la généralisation de l’utilisation des pesticides dans la sous-préfecture de Tapéguia. L’emploi des pesticides est influencé par des motivations socioéconomiques et agroécologiques diverses. Mais, les facteurs de risques de dégradation pour les agroécosystèmes se traduisent par la surexploitation des terres en jachère, l’utilisation non règlementée des pesticides par les agriculteurs qui ignorent ou ne considèrent pas les risques d’intoxication pour les agroécosystèmes. A cela, s’ajoutent le caractère de dépendance des producteurs aux pesticides agricoles et les problèmes de santé des agriculteurs (1.8% à 14.5% ressentent des malaises d’intoxication) dus à l’ignorance ou à l’inconsidération des risques et au manque de formations des agriculteurs sur les exigences de l’utilisation des pesticides

Characteristics of Positive Deviants in Western Chimpanzee Populations

With continued expansion of anthropogenically modified landscapes, the proximity between humans and wildlife is continuing to increase, frequently resulting in species decline. Occasionally however, species are able to persist and there is an increased interest in understanding such positive outliers and underlying mechanisms. Eventually, such insights can inform the design of effective conservation interventions by mimicking aspects of the social-ecological conditions found in areas of species persistence. Recently, frameworks have been developed to study the heterogeneity of species persistence across populations with a focus on positive outliers. Applications are still rare, and to our knowledge this is one of the first studies using this approach for terrestrial species conservation. We applied the positive deviance concept to the western chimpanzee, which occurs in a variety of social-ecological landscapes. It is now categorized as Critically Endangered due to hunting and habitat loss and resulting excessive decline of most of its populations. Here we are interested in understanding why some of the populations did not decline. We compiled a dataset of 17,109 chimpanzee survey transects (10,929 km) across nine countries and linked them to a range of social and ecological variables. We found that chimpanzees seemed to persist within three social-ecological configurations: first, rainforest habitats with a low degree of human impact, second, steep areas, and third, areas with high prevalence of hunting taboos and low degree of human impact. The largest chimpanzee populations are nowadays found under the third social-ecological configuration, even though most of these areas are not officially protected. Most commonly chimpanzee conservation has been based on exclusion of threats by creation of protected areas and law enforcement. Our findings suggest, however, that this approach should be complemented by an additional focus on threat reduction, i.e., interventions that directly target individual human behavior that is most threatening to chimpanzees, which is hunting. Although changing human behavior is difficult, stakeholder co-designed behavioral change approaches developed in the social sciences have been used successfully to promote pro-environmental behavior. With only a fraction of chimpanzees and primates living inside protected areas, such new approaches might be a way forward to improve primate conservation