Inventorying medium- and large-sized mammals in the African lowland rainforest using camera trapping

Abstract

I compiled a list of medium-and large-sized mammals (excluding Rodentia) in Moukalaba-Doudou National Park, Gabon. Additionally, I evaluated the efficiency of camera trapping for inventorying these animals. I placed 125 camera traps (set to "video mode" ) in forest and savannah in the eastern regions of the park, and compared my data with visual and acoustic observational records from the study area since 1999. I confirmed the occurrence of 38 species (11 Primates, 13 Carnivora, nine Ungulates, and five other taxa). During 4165 camera-days, my camera traps detected 29 out of the 38 species (76 %), including 10 newly-recorded species in the study area. However, a high proportion of cameras (40 %) in savannah were destroyed by Loxodonta africana. Furthermore, using this technique, it was difficult to detect arboreal species. It was also difficult to discriminate morphologically similar species (Cephalophus spp., Phataginus spp., and Galago spp.) from the captured images. These species can be more appropriately detected by visual sighting, acoustic hearing, and molecular techniques, suggesting that a combination of these techniques may increase the inventory efficiency. The number of forest-dwelling herbivores was lower in Moukalaba than in four other sites at or near Gabon, possibly because of separation from large Pleistocene refuges by a natural boundary. Nevertheless, Moukalaba harbors two savannah-dwellers─Kobus ellipsiprymnus and Herpestes ichneumon─which inhabit only a few protected areas of Gabon. The forest is invading the savannah, and therefore there is a requirement for regular burning, which must be enforced to preserve the totality of the existing biodiversity.

Etude de la Relation entre l’abondance des grands mammifères frugivores et celle des fruits dans le Parc National de Moukalaba-Doudou, Gabon

“…Chaque caméra piège a été attaché à un arbre à une hauteur d'environ 30 cm du sol et à 10 m de la ligne du transect (Nakashima, 2015 ;Hongo et al, 2016). Par ailleurs, toutes les caméras pièges ont été géo-référencées dans un GPS de marque GARMIN GPS MAP 60 CSX.…”

“…Ainsi, des séquences vidéos de 30 secondes de longueur ont été enregistrées. Chaque séquence a été considérée comme la preuve d'une seule visite par une espèce donnée, à condition que l'image ait été obtenue à un intervalle de temps supérieur à 30 minutes après l'image précédente de la même espèce (O'Brien et al, 2003;Nakashima, 2015 ;Hongo et al, 2016). Les cameras-pièges ont été visitées une fois par mois durant la période d'étude afin de changer les batteries et les cartes mémoires SD.…”

Application of DNA barcoding techniques to mammal inventories in the African rain forest: droppings may inform us of the owners

“…Therefore, the species in our sample was identified as a servaline genet. Hybridization between these two species has also reported (Gaubert et al 2006); therefore, it was Nakashima (2015). [3][4][5][6] Species with the same superscript number could not always be distinguished from one another even when using camera traps.…”

“…However, it is difficult to record nocturnal and/or shy mammal species by direct observation. As a result, recent advances in mammal inventories have involved the use of camera traps (Trolle 2003, Yasuda 2004, Srbek-Araujo and Chiarello 2005, Giman et al 2007, Tobler et al 2008, Nakashima 2015. Camera trapping has become one of the useful methods for monitoring large-and medium-sized terrestrial mammals.…”

“…Second, we conducted genetic species identification using the fecal samples of species that were easily identified based on their morphological characteristic, to confirm the accuracy of this method. Third, genetic species identification using the fecal samples of species that were difficult to identify based on their morphology was conducted, such as small carnivores and small ungulates which were abundant in the study area (Nakashima 2015). Finally, we discuss the utility of this method for mammal inventories and compared it with data collected by camera traps and direct observation.…”