Les gorilles du Parc National de Lobéké (Cameroun): interactions avec les populations locales et implications pour la conservation

La connaissance des interactions entre les populations locales et le gorille est nécessaire pour l’élaboration des stratégies de conservation durable dans une aire protégée. L’insuffisance d’informations de base sur ces interactions a motivé la présente étude autour du Parc National de Lobéké (PNL). Des entretiens et des enquêtes ont été menés auprès des  ménages, des gestionnaires de parc et des associations villageoises dans quatre sites autour du parc. Le résultat des enquêtes indique que le gorille est une source importante de revenus à travers le tourisme, les emplois locaux et des réalisations des opérateurs économiques. Cependant, ces retombées sont disparates selon les sites et restent d’ailleurs négligeables auprès des populations. D’autre part, le gorille génère les conflits, puisqu’il détruit les champs des riverains et est braconné par les populations. Les pertes en cultures sont rapportées par plus de 59% des ménages selon le site et sur près de 30% des superficies cultivées. Ainsi, les stratégies de redistribution des retombées et de résolution des conflits doivent tenir compte des spécificités de chaque site autour du parc. Il est recommandé de sensibiliser les populations à installer leur champ dans un périmètre où elles maîtrisent le contrôle.Mots clés: Gorille, Tri-National de la Sangha, conflit Homme-gorille, gouvernance

Climate-sensitive health priorities in Nunatsiavut, Canada

Background: This exploratory study used participatory methods to identify, characterize, and rank climate-sensitive health priorities in Nunatsiavut, Labrador, Canada. Methods: A mixed method study design was used and involved collecting both qualitative and quantitative data at regional, community, and individual levels. In-depth interviews with regional health representatives were conducted throughout Nunatsiavut (n = 11). In addition, three PhotoVoice workshops were held with Rigolet community members (n = 11), where participants took photos of areas, items, or concepts that expressed how climate change is impacting their health. The workshop groups shared their photographs, discussed the stories and messages behind them, and then grouped photos into re-occurring themes. Two community surveys were administered in Rigolet to capture data on observed climatic and environmental changes in the area, and perceived impacts on health, wellbeing, and lifestyles (n = 187). Results: Climate-sensitive health pathways were described in terms of inter-relationships between environmental and social determinants of Inuit health. The climate-sensitive health priorities for the region included food security, water security, mental health and wellbeing, new hazards and safety concerns, and health services and delivery. Conclusions: The results highlight several climate-sensitive health priorities that are specific to the Nunatsiavut region, and suggest approaching health research and adaptation planning from an EcoHealth perspective

Costs of Reproduction and Terminal Investment by Females in a Semelparous Marsupial

Evolutionary explanations for life history diversity are based on the idea of costs of reproduction, particularly on the concept of a trade-off between age-specific reproduction and parental survival, and between expenditure on current and future offspring. Such trade-offs are often difficult to detect in population studies of wild mammals. Terminal investment theory predicts that reproductive effort by older parents should increase, because individual offspring become more valuable to parents as the conflict between current versus potential future offspring declines with age. In order to demonstrate this phenomenon in females, there must be an increase in maternal expenditure on offspring with age, imposing a fitness cost on the mother. Clear evidence of both the expenditure and fitness cost components has rarely been found. In this study, we quantify costs of reproduction throughout the lifespan of female antechinuses. Antechinuses are nocturnal, insectivorous, forest-dwelling small (20–40 g) marsupials, which nest in tree hollows. They have a single synchronized mating season of around three weeks, which occurs on predictable dates each year in a population. Females produce only one litter per year. Unlike almost all other mammals, all males, and in the smaller species, most females are semelparous. We show that increased allocation to current reproduction reduces maternal survival, and that offspring growth and survival in the first breeding season is traded-off with performance of the second litter in iteroparous females. In iteroparous females, increased allocation to second litters is associated with severe weight loss in late lactation and post-lactation death of mothers, but increased offspring growth in late lactation and survival to weaning. These findings are consistent with terminal investment. Iteroparity did not increase lifetime reproductive success, indicating that terminal investment in the first breeding season at the expense of maternal survival (i.e. semelparity) is likely to be advantageous for females

Terminal Investment: Individual Reproduction of Ant Queens Increases with Age

The pattern of age-specific fecundity is a key component of the life history of organisms and shapes their ecology and evolution. In numerous animals, including humans, reproductive performance decreases with age. Here, we demonstrate that some social insect queens exhibit the opposite pattern. Egg laying rates of Cardiocondyla obscurior ant queens increased with age until death, even when the number of workers caring for them was kept constant. Cardiocondyla, and probably also other ants, therefore resemble the few select organisms with similar age-specific reproductive investment, such as corals, sturgeons, or box turtles (e.g., [1]), but they differ in being more short-lived and lacking individual, though not social, indeterminate growth. Furthermore, in contrast to most other organisms, in which average life span declines with increasing reproductive effort, queens with high egg laying rates survived as long as less fecund queens

The Influence of Reproductive Experience on Milk Energy Output and Lactation Performance in the Grey Seal (Halichoerus grypus)

Although evidence from domestic and laboratory species suggests that reproductive experience plays a critical role in the development of aspects of lactation performance, whether reproductive experience may have a significant influence on milk energy transfer to neonates in wild populations has not been directly investigated. We compared maternal energy expenditures and pup growth and energy deposition over the course of lactation between primiparous and fully-grown, multiparous grey seal (Halichoerus grypus) females to test whether reproductive experience has a significant influence on lactation performance. Although there was no difference between primiparous females in milk composition and, thus, milk energy content at either early or peak lactation primiparous females had a significantly lower daily milk energy output than multiparous females indicating a reduced physiological capacity for milk secretion

Abondance et distribution des grands singes et des activités humaines dans le Parc National de Campo Ma'an, Sud Cameroun

Abundance and Distribution of Great Apes and Human Activities in the Campo Ma'an National Park, South Cameroon. The Campo Ma'an National Park (CMNP) located in South Cameroon, has a rich biodiversity and is part of the priority areas of the Central Africa Network of Protected Areas. In order to improve the knowledge on great apes in this park, an inventory was conducted between October and November 2011 using the linear transect technique. In total, 103 transects, 2.5 km each, were established and surveyed. The results of the study confirm the presence of the two species of great apes in the CMNP, chimpanzees (Pan troglodytes troglodytes) and gorillas (Gorilla gorilla gorilla). The inventory suggested that chimpanzees had a nest density of 0.158 nest∙km-2, allowing an estimated density of 0.555 indiv.km-2, for a total population estimated at 1466 animals weaned throughout the Park. Chimpanzees were mainly located in the northern part of the Park, near the hilly area of Niété. Gorillas had an estimated average encounter rate of 1.080 sign per km. They also appeared to be more concentrated around the area of Niété. Poaching was the preferred type of human activity in the Park and was located in the northern part of the Park. It is strongly recommended to implement the results of this study by performing regular surveys, about every 3 months, in order to monitor the demography of the great apes populations in the Park

Adaptive adjustment of offspring sex ratio and maternal reproductive effort in an iteroparous mammal.

Large mammals in seasonal environments have a pattern of high-reproductive synchrony in spring, but how the timing of reproduction affects resource allocation decisions at different stages of the reproductive cycle remains largely unexplored. By manipulating the timing of conception in reindeer (Rangifer tarandus), we tested how the timing of conception affected sex ratio, gestation length and weight development of mother and offspring. Females that conceived at their first ovulation within the rut had a 60.5% probability of producing a male; in contrast, females that conceived a cycle later had a 31.3% probability of producing a male. Late conceiving females had gestation times that were 10 days shorter and the calves were 0.6 kg (9.2%) lighter at birth and 7.4 kg (14.7%) lighter in autumn. Over the year, female weight changes was similar between the groups suggesting reindeer follow a bet-hedging strategy; reducing the quality of this year's offspring to ensure their own future reproduction and survival. Harvesting is often selective leading to skewed sex ratios and age structure, which may influence the timing of reproduction due to females hesitation to mate with young males. Whenever this hesitation is strong enough to increase the frequency of recycling, harvesting is likely to have profound life history consequences