Updated distribution of spotted hyaenas in Gabon reveals resident populations

peer reviewedSpotted hyaena distribution currently widely encompasses sub-Saharan Africa, apart from the Congo Basin. Formerly described as residents of Gabon but considered extinct, vagrant individuals have been recorded since 2003, but no systematic species presence assessment has been made. Based on records of killed individuals, tracks and camera-trap sightings, we show that not only vagrant individuals are roaming in Gabon, but a small resident population occurs in the North-East of the country. The records collated here formed the basis for spotted hyaenas to be listed as protected in Gabon, were included in the IUCN Red List species' range map update and showcased the importance of large-scale by-catch data analysis in updating species distributions

Trypanosomiasis challenge estimation using the diminazene-aceturate (Berenil) index in Zebu in Gabon

A longitudinal study was conducted within a cattle ranch in Gabon to determine the diminazene aceturate (Berenil) index (DAI) in a group of Zebu, raised under low tsetse density; this measure providing an assessment of trypanosomiasis risk. The objective was to evaluate the trypanosomiasis pressure thus informing trypanosomiasis control methods and cattle management. Twenty female adult Zebu were monitored for 24 weeks during the dry season. Blood samples were collected on aweekly basis and subjected to parasitological and haematological analysis (n = 480), using the buffy-coat method and the packed cell volume value (PCV), respectively, infected animals were treated with a single intramuscular injection of diminazene aceturate (8 mg/kg). Twenty-nine single infectious events were recorded and a DAI of 1.45 was calculated. Two trypanosome species were identified: Trypanosoma congolense (96.2%) and Trypanosoma vivax (3.8%). The mean PCV value of the infected animals was lower (26.6) compared to non-infected animals (32.0). This study shows that DAI may be a useful tool to assess trypanosomiasis. However, this is a time-consumingmethod that may be improved by using randomly selected sentinel animals to adapt the chemoprophylactic schemes, hence decreasing the costs and the drug resistance risk

Conservation‐relevant reproductive parameters from long‐term tagging of two globally important sea turtle nesting aggregations in Central Africa

Assessing abundance and monitoring ecology and population trends are of critical importance for animal species of conservation concern. For sea turtles, annual nest counts represent the most common method of estimating population size. However, to develop a better understanding of population trends, these data need to be complemented by other reproductive parameters, which are lacking for many nesting populations across central Africa.To this end, an intensive capture-mark-recapture programme was conducted spanning 21 years (1997-2018) in the most important nesting sites on the Atlantic coast of central Africa (Gabon and Congo) for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) sea turtles.A total of 18,105 encounters of 14,109 D. coriacea individuals and 2678 encounters of 2427 L. olivacea individuals were recorded. Biological and technical parameters such as clutch frequency, inter-nesting interval, remigration interval, annual survival rate, somatic growth, size trends, tag loss and number of annual nesting females were estimated through a variety of methods and models.The study detected a decline in body size and low survival probability (not due to tag loss) in both species but no clear decline in estimated annual number of nesting females. High fidelity to nesting sites (<30 km for both species) implies that the current conservation strategy, protecting the main nesting areas, could be effective.We recommend that local conservation managers promote: (i) continued monitoring of the nesting activity of the two species through capture-mark-recapture programmes; (ii) continued nest counts at long-term monitoring sites, which may also detect possible spatial shifts; and (iii) strengthening of cross-border cooperation between Gabon and Republic of the Congo given the observed connectivity between nesting sites of the two countries