This article provides the first data on amphibian diversity in the Yoko Forest Reserve, located in the Democratic Republic of the Congo. During twenty-four field sampling campaigns organized over a period of twelve months, amphibians were collected from nocturnal surveys supported by three techniques: visual spotting using a headlamp, systematic searching of habitats and acoustic hearing of vocalizations. A total of 5707 amphibians in 10 families, 17 genera and 33 species were recorded throughout the study area. The Hyperoliidae and Arthroleptidae families were the most diverse, with Amnirana albolabris (Ranidae) the most abundant species, followed by Phrynobatrachus auritus (Phrynobatrachidae). By contrast, Afrixalus quadrivittatus, A. equatorialis, Arthroleptis tuberosus, A. variabilis, Cryptothylax greshoffi, Hyperolius langi, H. ocellatus, H. parallelus, Hyperolius sp., Hoplobatrachus occipitalis, Kassina maculosa, Leptopelis calcaratus, Nectophryne batesii, Phrynobatrachus perpalmatus, Sclerophrys gracilipes and S. gutturalis were less frequent. For the first time, Amietia nutti and Kassina maculosa have been reported in Congolese forests. Amphibian species known from the YFRE are widely distributed in Central African forests, and particularly in the Democratic Republic of the Congo, where A. equatorialis, H. langi, H. parallelus and Ptychadena christyi are endemic.

Anthropogenic disturbance of natural environments has negative impacts on biodiversity. Amphibians are especially sensitive to deforestation, and there is a high rate of this phenomenon in the Democratic Republic of the Congo. We studied the effects of this modification of forest ecosystems on the diversity of amphibians in the Yoko Forest Reserve. During twenty-four field sampling campaigns organized over a period of twelve months, amphibians were collected from nocturnal surveys supported by three techniques: visual spotting using a headlamp, systematic searching of habitats and acoustic hearing of vocalizations. Twelve sampling sites were chosen, and three habitats were explored at each site. Of these three habitats, one is the undisturbed habitat (primary forest), and two are disturbed habitats (fallow and field). Amphibian abundance, species richness, diversity, evenness and density were compared between these two types of habitat. A total of 4443 amphibians in 10 families, 17 genera and 33 species were recorded throughout the study area. Abundance, species richness and relative density were significantly higher in non-disturbed habitats than in disturbed habitats. On the other hand, primary forest is less diverse than fallow, but not significantly. It is, however, significantly more diverse than the field. The undisturbed habitat is also characterized by lower evenness than the disturbed habitats, with which it shares low similarities. The species Amnirana albolabris, Phrynobatrachus auritus, Leptopelis notatus, Leptopelis millsoni, Xenopus pygmaeus, Hyperolius platyceps, Leptopelis calcaratus, Leptopelis christyi, Leptopelis ocellatus, Arthroleptis tuberosus, Ptychadena perreti, Amietia nutti, Arthroleptis variabilis, Cardioglossa leucomystax, Phrynobatrachus perpalmatus and Chiromantis rufescens were recognized, in order of importance, as primary forest indicators according to the results of this study. All these differences between the two habitat statuses (undisturbed and disturbed) confirm the negative effects of natural habitat alteration on forest amphibians.

Conservation measures require accurate estimates of density and abundance and population trend assessments. The bonobo (Pan paniscus) is considered Endangered in the IUCN Red List. This classification assumes that available population data are representative. However, with only 30% of the bonobo’s historic geographical range surveyed, reliable information is needed to assess the species' population status. Here, we use information from 13 surveys conducted between 2002 and 2018 in an area of 42,000 km², representing ~27% of bonobo-suitable habitat: Salonga National Park and its corridor, Democratic Republic of the Congo (DRC). Using 8310 km of reconnaissance and transect walks and 27,045 days of camera trapping, we: (1) provide updated estimates of bonobo population density and distribution (42,000 km²; ~5,000 km² of which, to the best of our knowledge, have not been surveyed before by scientists), (2) assess population trends (15,758 km²; 2002–2008 vs 2012–2018), (3) compare estimates obtained with different methods, and (4) assess the factors driving bonobo density and distribution. Although we detected a non-significant population decline, our study suggests that Salonga is a bonobo stronghold, with a population ranging between 8244 and 18,308 mature individuals (density: 0.31 individuals/km²). Standing crop nest counts returned non-significantly lower density estimates than camera trap distance sampling. Nest count-estimates were higher in areas with Marantaceae understorey and those farther away from rivers, while camera trap-estimates were higher in areas with lower human presence. Regardless of the method, bonobos were rarer in proximity to villages. They occurred more often in areas of dense forest cover and in proximity to ranger posts. Our results point towards a declining bonobo population in Salonga, but do not provide sufficient evidence to confirm this statistically. Consequently, the continued monitoring of the bonobo population and preservation of the integrity of Salonga, considering its biological and cultural heritage, will be crucial in the preservation of this stronghold of wild bonobos.

Ce travail présente les résultats d’une méta-analyse de quatre études menées sur les Amphibiens à Kasugho, Butembo, Mambasa et Kisangani en République Démocratique du Congo. L’objectif principal était de vérifier le lien entre le taux d’anthropisation des habitats et la fréquence des espèces observées afin d’identifier d’éventuelles espèces indicatrices des perturbations anthropiques. L’observation directe a généré 815 Amphibiens capturés dans les habitats anthropisés (étang piscicole, jachère) et non anthropisés (marécage, forêt secondaire, forêt primaire). Sur les 37 espèces identifiées, 2 (Amietophrynus kisoloensis, Hoplobatrachus occipitalis) vivent uniquement dans les habitats anthropisés et 11 (Afrixalus quadrivittatus, Amietophrynus gracilipes, Arthroleptis variabilis, Cardioglossa gracilis, C. leucomystax, Hyperolius viridiflavus, Leptopelis aubryioides, L. ocellatus, Phrynobatrachus auritus, Ptychadena anchietae, P. chrysogaster) préfèrent uniquement les habitats non anthropisés. La plus forte similarité entre les habitats anthropisés et non anthropisés a été observée à Mambasa (étang piscicole, marécage, jachère, forêt secondaire, forêt primaire) et la plus faible entre les habitats à Butembo (marécage, jachère). Un test de Chi-carré souligne un lien entre le statut d’habitat et les abondances d’Amphibiens. Une corrélation linéaire significative confirme qu’il n’y a pas de relation directe entre les fréquences dans les deux statuts d’habitat. La présente étude confirme le potentiel des Amphibiens comme indicateurs de perturbations anthropiques des écosystèmes.

Background and Aim : Anthropogenic disturbance of natural environments impacts animal communities. This study aimed to identify amphibian species adapted to inhabited areas and those consumed as game in Kisangani and its surrounding regions (Democratic Republic of the Congo). Methods: From February to September 2021, nocturnal surveys were conducted using visual spotting with headlamps, systematic habitat searching, detection acoustic of calls. Also, interviews were done with 545 respondents. Results: A total of 1715 individuals belonging to 7 families, 9 genera and 15 species (Afrixalus quadrivittatus, A. osorioi, Chiromantis rufescens, Hoplobatrachus occipitalis, Hylambates verrucosus, Hylarana galamensis, Hyperolius cinnamomeoventris, H. kivuensis, H. parallelus, Phrynobatrachus perpalmatus, Ptychadena mascareniensis, P. perreti, Sclerophrys gracilipes, S. gutturalis and S. pusilla) were recorded. Additionally, interviews revealed that seven species (Amietia nutti, Hoplobatrachus occipitalis, Hylarana albolabris, Ptychadena mascareniensis, P. perreti, Xenopus pygmaeus and X. ruwenzoriensis) are consumed as bushmeat primarily by the Kumu and Topoke ethnic groups. Frogs are preserved fresh, salted or smoked, and cooking methods include boiling, grilling, frying and baking in leaves. Consumption practices are rooted in cultural, religious and medicinal beliefs, as well as fear of certain "dangerous" species. Conclusion : These findings highlight both the adaptability of amphibians to inhabited environments and their cultural and dietary significance in local communities. Implications for conservation : The study underscores the importance of considering human-amphibian interactions in conservation strategies within rapidly changing ecosystems.

Edges provide valuable insight into the effects of landscape structure on forest ecosystems and faunal distribution. This study assessed edge effects on amphibian diversity in the Yoko Forest Reserve, Democratic Republic of the Congo. Over twelve months (from December 2020 to November 2021), amphibians were surveyed during 24 nocturnal field campaigns using visual detection, habitat searches, and acoustic hearing of vocalizations. Twelve sites were sampled, each including five habitats: primary forest, fallow, field, and two edge types (primary forest-fallow and primary forest-field). Amphibian abundance, species richness, diversity, evenness, and relative density were compared between each edge and its adjacent habitats. A total of 5516 individuals (33 species, 17 genera, 10 families) were recorded. Edges had lower abundance, richness and density than the primary forest but higher than adjacent disturbed habitats. The forest-fallow edge maintained similar diversity to the primary forest, while the forest-field edge showed significantly lower diversity. Forest evenness was lower than at both edges. Several species, including Hylarana albolabris, Leptopelis calcaratus, L. christyi, L. millsoni, L. notatus, L. ocellatus and Sclerophrys pusilla showed intermediate abundances at the primary forest-fallow edge. Similarly, Afrixalus osorioi and Ptychadena mascareniensis showed intermediate abundances in the primary forest-field edge. Scelophrys gracilipes and S. pusilla showed a positive preference for the primary forest-field edge. Afrixalus osorioi, A. quadrivittatus, Chiromantis rufescens, Hylambates verrucosus, Hyperolius sp., H. langi, H. ocellatus, Leptopelis calcaratus, Ptychadena christyi, P. mascareniensis, P. perreti, Sclerophrys gutturalis and S. gracilipes showed a positive preference for the primary forest-fallow edge. Among these species, Chiromantis rufescens and P. mascareniensis showed a moderate but significant preference for this edge, enabling them to be considered specialists of this habitat. These results confirm the structuring role of edges in forest amphibian population’s dynamics.