Poaching in the Kakum Conservation Area of Ghana.

Tropical forests have come under unprecedented threat in recent decades, with wildlife populations threatened by both the felling of forests and hunting. To remedy this, many countries have introduced protected areas such as national parks within areas of tropical forests, within which the hunting or harvesting of wild animals and plants is strictly controlled or completely forbidden. Unfortunately, such schemes are typically imposed by central governments without any input from local communities that have lived in, and extracted resources from, these forests for centuries or more. This can mean that such communities suddenly find traditional sources of income and sustenance are suddenly forbidden, whereas any income from the new reserves typically goes into central government coffers, creating an sense of alienation, and a subsequent reluctance to cooperate with park schemes.

In a paper published in the Journal of Threatened Taxa on 26 February 2018, Edward Debrah Wiafe of the Department of Environmental and Natural Resources Management at the Presbyterian University College in Akropong-Akuapem, Ghana, presents the results of a 13 month study of poaching in the Kakum Conservation Area of southern Ghana.

The Kakum Conservation Area comprises the Kakum National Park, with an area of 210 square kilometres, and the Assin Attandanso Resource Reserve, covering 150 square kilometres. These were originally created during the colonial period (1931 and 1937 respectively), in order to protect the watershed that supplied the Cape Coast region, and to provide a source of timber. Establishing forest parks for the benefit of the timber industry might seem slightly contradictory, but in Britain, the colonial power in Ghana at the time, all natural forests vanished centuries ago, and with timber coming from managed and protected woodlands harvested on a rotational basis, with trees being left to grow for decades unmolested; unprotected areas tend to be rapidly converted to arable production, which produces a crop every year. The forests at Kakum were home to a number of local communities, which relied on the forests to provide them with resources through hunting and gathering, and occasionally some artisanal gold and clay mining, but little timber harvesting is thought to have occurred before the forest parks were created.

A raised walkway in the Kakum National Park; a popular attraction with tourists that provides a useful source of hard currency. Nicola Chiappi/Wikimedia Commons.

Today the area is protected by Wildlife Protection Rangers armed with G.P.S. units, compasses, grid maps and riffles, who enforce strict rules prohibiting anybody from hunting any animal or removing any plant from the reserve without express written permission, effectively making all hunting illegal. The reserve is home to a number of protected Mammals and Birds including African Elephant, Loxodonta africana, Maxwell’s Duiker, Philantomba maxwellii, Black Duiker, Cephalophus niger, Bongo, Tragelaphus eurycerus, Lowe’s Monkey, Cercopithecus lowei, Olive Colobus, Procolobus verus, Black and White Colobus, Colobus vellerosus, and Yellowbilled Turaco, Tauraco macrorhynchus. It is also home to 53 Human communities, who are now reliant on subsistance farming.

Wiafe collected data on arrests made by Wildlife Protection patrols between November 2012 and November 2013, including the number of arrests, the time of poaching equipment they were using and the numbers and types of animals they were caught with.

In November 2012 the patrols arrested two poachers, armed with snares and shotguns, and in possession of one Maxwell’s Duiker, 27 Rats and two live Pangolins. In December 2012 three poachers were arrested, armed with shotguns and in possession of ne Maxwell’s Duiker and two Pangolins.

A Maxwell’s Duiker, Philantomba maxwellii, considered to be Least Concern under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species and hunted by poachers in the Kakum Conservation Area of Ghana. Paul Cools/iNaturalist/ICUN Red List.

In January 2013 the patrols arrested one poacher, armed with a shotgun, and in possession of two Maxwell's Duiker, one Lowe's Monkey, and one Spot-nosed Monkey. In February one poacher was arrested, in possession of snares and two Maxwell's Duiker, one Royal Antelope, one Tree Squirrel and a Potto. In march 2013 a single poacher was apprehended, armed with a shotgun and in possession of one Maxwell's Duiker and one Lowe's Monkey. In April 2013 no poachers were arrested.

A Lowe's Monkey, Cercopithecus lowei, in the Mole Game Reserve in Ghana. This species is again considered to be of Least concern under the terms of the ICUN's Red List, and is hunted in the Kakum Conservation Area of Ghana. Peter Strong/Wikimedia Commons.

In May 2013 four poachers were arrested, armed with shotguns and in possession of five Maxwell's Duiker, two Royal Antelope, two Lowe's Monkeys, and one Spot Nosed Monkey. In June no poachers were apprehended again, while in July 2013 three poachers were arrested, in possession of shotguns and having killed two Maxwell's Duiker, one Lowe's Monkey and one Elephant.

African Elephant, Loxodonta africana, in the Kakum National Park. The species is considered to be Vulnerable under the terms of the ICUN's Red List. Kakum National Park.

 

In August 2013 the patrols arrested one poacher, armed with a shotgun and in possession of one Royal Antelope, one Flying Squirrel, one Lowe's Monkey, one Olive Colobus, and one live Pangolin. No poachers were apprehended in September or October 2013, while in November 2013 another single poacher was arrested, this time armed with a shotgun and and in possession of one Maxwell's Duiker, two Lowe's Monkeys and two live Pangolins.

A Long-tailed Pangolin, Uromanis tetradactyla, in the Kakum National Park. One of three Pangolin species in the area, all of which are considered to be Vulnerable under the terms of the ICUN's Red List. Lars Peterson.

During the time of the study 69 animals were recovered by Wildlife Protection Rangers in the Kakum National Park, including 29 Rodents, 19 Antelope, 13 Primates, seven Pangolins, and an Elephant. Of these eight belonged to species considered to be Vulnerable under the terms of the ICUN's Red List of Threatened Species (the Pangolins and the Elephant) one belonged to a species considered to be Near Threatened (the Olive Colebus), while the remainder belonged to species considered to be of Least Concern. This pattern did not vary notably from that in areas where hunting is not illegal.

The favoured weapon of the Poachers was clearly the shotgun, which Wiafe notes is the weapon most conservationists would prefer to see used, as it is a discriminating weapon which allows hunters to only take the animals they want, unlike snares which are more random. This is not always the case in protected reserves, as the sound of shotguns can attract the attention of patrols, however in this instance the hunters reported preferring shotguns as they enable them to target animals in the tree canopy. However the Wildlife Rangers also reported sometimes finding fencing around paths in the reserves, directing animals to snares outside the bounds of the protected area.

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Calculating the role of Pleistocene refugia in explaining the distribution of modern Duiker populations.

Although not affected by extensive glaciations during the Pleistocene, Africa is thought to have had periods of much cooler and drier climate which correspond the the glaciations in Eurasia and North America. During these periods the tropical forests which cover much of West and Central Africa are thought to have shrunk into a series of refugia, smaller forest patches from which forest species spread to cover the remainder of the area in warmer and wetter periods. Many modern groups of animals and plants have distributions that are thought to derive from these refugia, with species, subspecies or populations thought to have derived from different refugia still having distinct distributions within modern continuous forests. However examination of the various groups of animals and plants found in African forests appear to suggest different numbers of refugia, with different studies suggesting different numbers of refugia providing different origins for modern populations in the same regions.

In a paper published in the journal BMC Evolutionary Biology on 6 September 2017, Stephan Ntie of the Department of Biology at the Université des Sciences et Techniques de Masuku, and the Department of Biological Sciences at the University of New Orleans, Anne Davis, also of the Department of Biological Sciences at the University of New Orleans, Katrin Hils of the Cheetah Conservation Fund and the Institute for Evolution and Ecology at the University of Tübingen, Patrick Mickala, also of the Department of Biology at the Université des Sciences et Techniques de Masuku, Henri Thomassen, also of the Institute for Evolution and Ecology at the University of Tübingen, Katy Morgan, also of the Department of Biological Sciences at the University of New Orleans, Hadrien Vanthomme of the Département Ecologie et Gestion de la Biodiversité at the Muséum National d’Histoire Naturelle, Mary Gonder of the Department of Biology at Drexel University, and Nicola Anthony, once again of the Department of Biological Sciences at the University of New Orleans, describe the results of a study into the populations of modern Duikers, Cephalophinae, in modern West-Central African rainforests, with a view to understanding if this distribution derives from Pleistocene refugia.

Duikers are small-to-medium-sized Antelope found in dense forests in sub-Saharan Africa. The group is thought to have originated in the Miocene, and is composed of specialist browsers (feeding on leaves, shoots and fruits) rather than grazers (feeding on grass) like other Antelope. There are currently sixteen species of Duiker, split into three genera, many of which have overlapping ranges, but which are able to co-exist due to different ecological roles and diets.

A Bay Duiker, Cephalophus dorsalis, photographed slightly outside the Akanda National Park in Gabon in July 2012. Lyse Primault/Wikimedia Commons.

Studies of other groups suggest there were probably four refugia in the West-Central Africa region, the Gulf of Guinea Refugia in the volcanic mountains between Cameroon and Nigeria, the South-western Cameroon Refugia in coastal Cameroon to the south of the Sanaga River, the Equatorial Guinea and northern Gabon Refugia in the coastal forests spanning the borders between Equatorial Guinea and Gabon and the Southern Gabon Refugia to the south of the Ogooué River in Gabon.

In order to assess the distribution of modern Duiker populations in the region, Ntie et al. collected samples of Duiker dung from the Cross River National Park in Nigeria, the Takamanda National Park, Campo Ma’an National Park, and Lobéké National Park in Cameroon, the Monte Alén National Park, Monte Mitra, and Bioko Island in Equatorial Guinea, the Monts de Cristal National Park, Birougou National Park, Gamba Complex of Protected Areas and Minkébé National Park in Gabon, the Nouabelé Ndoki National Park in the Republic of Congo, the Mbaéré-Bodingué National Park in the Central African Republic, and the Salonga National Park in the Democratic Republic of Congo. In addition museum specimens from the Mount Nimba Strict Nature Reserve in Guinea, Cape Province in South Africa, the Dja Faunal Reserve, and area around the town of Bamenda in Cameroon, Lefini Reserve, Odzala National Park and area around Brazzaville in the Republic of Congo, Mbaéré-Bodingué National Park in the Central African Republic, area around Mitzic in Gabon, and area around Kisangani in the Democratic Republic of Congo

These samples were analysed for traces of mitochondrial DNA (mtDNA). Because mitochondrial DNA is found in the mitochondria, organelles outside the cell nucleus, it is passed directly from mother to child without being sexually recombined each generation, enabling precise estimations of when individuals shared common ancestors, at least through the female line (it is also possible to trace direct ancestry through the male line, using DNA from the Y chromosome, which is passed directly from father to son without sexual recombination), enabling Ntie et al. to determine the species of Duiker that produced each stool, and sort the samples into discrete lineages with common ancestry within each species.

A Blue Duiker, Philantomba monticola. Derek Keats/Wikimedia Commons.

Ntie et al. were able to recover mtDNA from six species of Duiker, the Bay Duiker, Cephalophus dorsalis, the Peter's Duiker, Cephalophus callipygus, the Yellow-backed Duiker, Cephalophus silvicultor, the Black-fronted Duiker Cephalophus nigrifrons, the White-bellied Duiker Cephalophus leucogaster, and the Blue Duiker, Philantomba monticola, plus the Water Chevrotain, Hyemoschus aquaticus and the Sitatunga Tragelaphus spekii, which are ecologically similar Ruminants. However, only three species, the Bay Duiker,the Peter's Duiker and the Blue Duiker, were found in more than three locations, preventing the inclusion of any of the other species in the study.

Stool samples from the Bay Duiker were found at all areas except Cross Rivers in Nigeria and Cape Province in South Africa. However, there appeared to be no clear population structure within this species, suggesting that individuals of this species range widely between locations, and that if they ever were restricted to refugia all traces of this have long since been overwritten by breeding migration between populations.

Both the Peter's Duiker and the Blue Duiker were also present in most locations (neither was found in Guinea and the Peter's Duiker was also absent in Cape Province and the Central African Republic). In both these species two distinct lineages appeared to be present, with populations in Nigeria and northern Cameroon apparently separate from all other populations.

A Peter's Duiker, Cephalophus callipygus, in the Campo Ma’an National Park in Cameroon. Wikimedia Commons.

This strongly suggests that the Peter's Duiker and the Blue Duiker were reduced to at least two separate populations during the Pleistocene glaciations, one in the Gulf of Guinea Region and one to the south; though it cannot be determined if these southern populations were restricted to single forest fragments, or were found in more than one fragment but able to move between them (Duiker cannot survive and reproduce for long periods in open grassland, but are certainly capable of crossing it).

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