Differential response of seven duiker species to human activities in Taï National Park, Côte d'Ivoire

Abstract

African rainforest is severely impacted by human activities, ranging from resource collection, selective logging to fragmentation and scale deforestation. Consequently, large mammal communities occurring therein are strongly modified. Here, we present a study conducted in Taï National Park (TNP), which characterises the spatial distribution and differential response of seven duiker species to human activities. Based on extensive survey data recorded between 2005 and 2015, we used a maximum entropy modelling approach for predicting duiker species distribution and a hierarchical clustering approach to identify potential subgroups in the duiker community. The seven duiker species clearly differed in their spatial distribution, with Cephalophus dorsalis and Philantomba maxwellii being the most common and widely distributed with no clear response towards gradients of impact from human activities. In contrast, Cephalophus ogilbyi, Cephalophus jentinki, Cephalophus sylvicultor and Cephalophus zebra showed increasing responses towards anthropogenic impact gradients, with the latter two being particularly sensitive. These duikers are not found in areas of illegal human activities. The restricted distribution of Cephalophus niger seems artificial and may indicate species misidentification. The strong spatial signature of human activities in the duiker community of TNP is of concern. Effective park management, including extensive ranger patrols, is vital for ensuring the persistence of this unique duiker community in West Africa.

High abundance and large proportion of medium and large duikers in an intact and unhunted afrotropical protected area: Insights into monitoring methods

“…We also found high‐density estimates of large duikers and high camera trap detection rates of yellow‐backed duikers, indicating that this species might be more abundant than previously documented (Kamgaing et al., 2018; Nakashima et al., 2013) (Table 1). Further studies are needed to investigate species specific vulnerability to hunting, particularly between different red duiker species (Diarrassouba et al., 2020; Kamgaing et al., 2019; Yasuoka et al., 2015).…”

“…Often, it is impossible to identify the duiker species and grouping duikers by dung bolus size (small = blue duiker; medium = red duiker species, large = yellow‐backed duiker) is prone to substantial error (Van Vliet et al., 2007). This makes it challenging to fully understand species specific vulnerability to hunting, despite the fact that duiker species respond differently to hunting (Diarrassouba et al., 2020; Van Vliet, Nasi, et al., 2007). There are also errors associated with the multipliers that convert dung density to duiker density because dung decay rates vary enormously between sites due to environmental conditions (e.g.…”

Distance sampling of duikers in the rainforest: Dealing with transect avoidance

“…Lastly, changes in community composition can also be used as an ecological indicator. For example, it has been demonstrated several times that the ratio of blue duikers to larger species of duiker increases along gradients of hunting pressure [15,63], probably under the combined influence of hunter selectivity and of the faster pace of life of the blue duiker relative to larger species. The change over time in the ratio of large to small species [8] or the ratio of long-lived to short-lived species [64] could therefore constitute an efficient indicator of the defaunation process.…”

Périodes d’activités et structure sociale de Cephalophus zebra Gray, 1838 et de Cephalophus jentinki Thomas, 1892 dans le Parc National de Taï, Sud-Ouest de la Côte d’Ivoire

“…Parmi ces ongulés, deux espèces de la famille des bovidés sont menacées d'extinction et sont endémiques pour la région de l'ouest de la Sierra Léone jusqu'au Sud-Ouest de la Côte d'Ivoire. Il s'agit du céphalophe zébré (Cephalophus zebra Gray, 1838) et du céphalophe de Jentink (Cephalophus jentinki Thomas, 1892) (Diarrassouba et al, 2019).…”

“…En effet, une étude des adaptations des céphalophes aux perturbations de l'environnement débutée en 1989 dans le parc, n'a pu être menée jusqu'à terme (Lauginie, 2007). Au-delà de cette étude, celles qui ont pu être menées dans le parc, ont porté généralement sur toutes les 7 espèces de céphalophes (Cephalophus dorsalis, Philantomba maxwelli, Cephalophus niger, Cephalophus sylvicultor, Cephalophus jentinki, Cephalophus zebra et Cephalophus ogilbyi (Lauginie, 2007 ;Diarrassouba et al, 2019). Elles ont traité notamment, de leur abondance et de leur distribution (Tiedoué et al, 2015(Tiedoué et al, , 2016(Tiedoué et al, , 2018, l'effet des facteurs naturels et anthropiques sur celles-ci (Diarrassouba et al, 2019) et leurs périodes d'activités (N'Goran et al, 2020).…”