|Scientific Name:||Potamochoerus porcus (Linnaeus, 1758)|
Sus porcus Linnaeus, 1758
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Reyna, R., Jori, F., Querouil, S. & Leus, K.|
Listed as Least Concern because the species is relatively widespread and common, and there are no major threats believed to be resulting in a significant population decline. However, hunting has led to localised declines in some parts of its distribution, so populations should be monitored carefully on those specific areas.
|Previously published Red List assessments:|
The Red River Hog is widely but patchily distributed through the West and Central African rainforest belts, from Senegal in the west, throughout the Guinea-Congo forest to at least west of the Albertine Rift. Further east and south-east, the Red River Hog becomes replaced by the Bushpig (Potamochoerus larvatus), although the precise borders between the distributions of the two species remain unclear. Grubb (1993) reported that the two species may be present in the Rift highlands of Democratic Republic of Congo, Republic of Rwanda and Republic of Burundi but separated by elevation with P. larvatus only occurring on mountain slopes and P. porcus only occurring in lowland forest. There are no confirmed records from North Sudan or Chad, although Red River Hog was recorded recently in South Sudan (Dasgupta 2015). There are no reliable records from The Gambia, which is just outside their natural distribution (Grubb et al. 1998), and there is no confirmation of their presence on Bioko Island. In Senegal, Red River Hog has become so rare that it is considered endangered and integrally protected species in national law (F. Jori pers. comm.).
Native:Benin; Cameroon; Central African Republic; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Equatorial Guinea; Gabon; Ghana; Guinea; Guinea-Bissau; Liberia; Mali; Nigeria; Senegal; Sierra Leone; South Sudan; Togo; Uganda
|Range Map:||Click here to open the map viewer and explore range.|
Recorded densities for Red River Hogs vary greatly, but typically range between 1-6 individuals/km² (Leus and Vercammen 2013). Periodic aggregations on ephemeral resources (such as masting fruit trees) might explain these higher estimates (Blake and Fay 1997, Abernethy and White 1999, Melletti et al. in press). Leslie and Huffman (2015) summarized several studies of density (individuals/km²) on P. porcus with 1.3-5.6 individuals/km² (0.04–0.17 groups/km²) in the forested areas of Lopé National Park, Gabon (White 1994); 18.4 individuals/km² were recorded from galleries and forest patches in the savanna ecotone of Lopé Reserve, Gabon (Tutin et al. 1997); 3.1 individuals/km² in Equatorial Guinea (Fa et al. 1995); and 2.0 individuals/km² in Réserve de Fauna á Okapis, Ituri Forest, Democratic Republic of the Congo (Hart et al. 1996). Other studies have shown densities of 7.31 individuals/km² and 0.26 groups/km² in the coastal forest of Réserve de Faune du Petit Loango, Gabon; 4.74 individuals/km² (95% CI 3.22-6.55) near Campo-Ma’an, Cameroon (van der Hoeven et al. 2004); and 1.52 individuals/km² in Taï National Park, Cóte d’ Ivoire (Hoppe-Dominik et al. 2011). However, these variations should be interpreted with caution because they can reflect local differences of density but also differences in the efficiency of different methods applied, which in some case are influenced by vegetation thickness and visibility.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
Typically associated with rainforest and gallery forest, Red River Hogs have also been observed in other habitats such as dry forest, savanna woodland and cultivated areas, although usually in close proximity to rainforest (Leus and Vercammen 2013). Like the Bushpig, Red River Hogs are highly adaptable and may even benefit from the opening up of former forested areas, by the creation of secondary habitats, by the provision of cultivated foods, or by the reductions in the numbers of their natural predators (Vercammen et al. 1993). In Dzanga-Ndoki National Park, southwestern Central African Republic, P. porcus primarily uses mixed forest (with varying densities of understory vegetation) but was seen in 5 types of vegetation including grassy clearings (Melletti et al. 2009). There is very scarce information on movements or home range for P. porcus: in Dzanga-Nodki National Park in the Central Africa Republic and Republic of Congo daily movements ranged from 2 to 4 km in secondary rainforest and home ranges varied annually between 4 to 10 km² (Melletti et al. in press). Sometimes large aggregations of Red River Hogs up to 60 animals have been observed and may concentrate in specific areas where there are masting trees that imply possible occasional long movements in the species (Abernethy and White 1999, Leslie and Huffman 2015, Melletti et al. in press). Red River Hogs are mixed feeders, consuming fruits and seeds, and have been seen scavenging carcasses (Turkalo 2010). In the Dzanga bai of Central Africa Republic, Red River Hogs are reported to be attracted to forest clearings for rooting through elephant dung in search of seeds and larvae (Turkalo pers. comm.). On several occasions they have been observed cracking open seeds of Panda oleosa. Twelve years of data showed that Red River Hogs were more frequently observed in the clearings during the dry months of the year (Turkalo pers. comm.). Red River Hogs are gregarious and often seen in groups of 7 to 10 individuals (Leslie and Huffman 2015). However, group sizes observed in the Dzanga clearing range from single individuals to groups as large as twenty-seven. In the Dzanga bai, the average group size was calculated at 4.9 individuals (including single individuals) and an average of 10.2 without single individuals (Turkalo pers. comm.). When conditions are good, sounders can aggregate in groups of > 60 individuals (Vercammen et al. 1993, Abernethy and White 1999, Leslie and Huffman 2015, Melletti et al. in press). In Loma Mountains Non-Hunting Reserve (Sierra Leone), mean group sizes were 5.6, 8.5 and 10.5 in gallery forest, grasslands and forest habitats, respectively (Kortenhoven 2009); In Nigeria, groups with an average of 10.6 individuals were reported (Oduro 1989).
|Use and Trade:||Red River Hogs are subject to bushmeat hunting of variable intensity in several countries of Africa.|
Although considered a common and abundant species (Oliver 1995), the Red River Hog is one of the preferred species for subsistence hunters across its range in Africa. Tropical Africa has changed dramatically in recent years (Malhi et al. 2013) and increasing human densities are correlated with increasing rates of hunting. As a result, Red River Hog is also one of the primary prey species harvested for commercial purposes within the bush meat trade in most of Central Africa including Cameroon (Ayeni et al. 2001, Fa et al. 2006, Wilcox and Nambu 2007, Wright and Priston 2010, Macdonald et al. 2012), Central African Republic (Noss 1998), Democratic Republic of Congo (Mockrin et al. 2011, Dupain et al. 2012), Equatorial Guinea (Fa et al. 1995), Gabon (Thibault and Blaney 2003, Van Vliet and Nasi 2008), and some forested areas of West Africa such as Liberia (Bene et al. 2013) and Nigeria (Angelici et al. 1999, Okiwelu et al. 2009, Lameed et al. 2015). Together with the duikers, it is one of the most hunted species in the Congo Basin where a 79 % density decline was estimated from 1.7 individuals /km² in non-hunted areas to 0.36 individuals/km² in hunted areas (Lahm 1994). A significant effect of hunting on Red River Hog densities was observed in southern Gabon (Laurance et al. 2006). In some countries, Red River Hogs damage maize crops, and for this reason the species is persecuted by farmers. In general these persecutions fail to eradicate Red River Hogs locally because they avoid active hunting through their nocturnal behaviour, and have a high reproductive output (Vercammen et al. 1993). Another threat is habitat loss (primary or secondary forest) and human encroachment in their habitat, which leads to overhunting. This is more likely to occur in West Africa. As an example, the Red River Hog has become very rare in Senegal and holds a status of integral protection (http://www.au-senegal.com/IMG/pdf/especes-protegees.pdf)
Although the species is protected in most reserves and national parks in West and Central Africa, law enforcement is a problem and in many cases non-existent. Deforestation is not considered a major threat to Red River Hog populations, and this species can benefit from a mosaic of habitats. However, the high human activity in mosaic landscapes is often associated with high hunting pressure that may cause the contraction of the species' distribution, in particular in Benin, Sierra Leone, Senegal, and some parts of the Congo Basin such as Equatorial Guinea. According to Vercammen and colleagues (1993), the localized introduction of Eurasian Wild boar in some African countries such as Burkina Faso, Gabon and DRC could have led to the occurrence of hybrids between these two species, although the extent of this hybridization has not been fully described (Vercammen et al. 1993). In other areas, further threats to the species’ genetic integrity could originate from a suspected hybridization with free-ranging domestic pigs Sus scrofa (Jori and Bastos 1989). In addition, genetic studies should be conducted in areas of overlap with P. larvatus because some questions related to systematic relationships between these two species remain unresolved. Reports exist of polymorphism in some of these overlapping populations and full genome studies are needed to elucidate levels of introgression and to draw appropriate taxonomic conclusions. Finally, in some regions, populations appear to be in substantial decline due to the impact of the bushmeat trade, and these populations require improved protection and management to prevent their local extinction (Vercammen et al. 1993). Many aspects of Red River Hog biology, ecology, behavior and population status remain unknown and require further investigation.
|Errata reason:||Updated the order of authors for a reference used in this assessment.|
|Citation:||Reyna, R., Jori, F., Querouil, S. & Leus, K. 2016. Potamochoerus porcus. (errata version published in 2016) The IUCN Red List of Threatened Species 2016: e.T41771A100469961.Downloaded on 21 September 2017.|