Turtles and Tortoises of Togo: Historical Data, Distribution, Ecology, and Conservation
Abstract
The chelonian fauna of Togo (West Africa) has been scarcely studied to date. In this article, we review and summarize all available data on the distribution, ecology, and conservation status of the chelonian species of Togo and present a short historical perspective on the development of studies on these reptiles. Overall, 13 chelonian species are found in Togo, 4 being marine, 3 terrestrial, and 6 freshwater. Among the marine species, only 2 of them nest on Togolese beaches (Lepidochelys olivacea and Dermochelys coriacea). Two species (Chelonia mydas and L. olivacea) are still locally common. Concerning the terrestrial and freshwater species, they differed remarkably in terms of their distribution by ecological zone. Cluster analyses revealed the existence of 3 clusters of species, 1 that contains the “forest” species, 1 accommodating the Sudanese savannah species, and a third cluster for the generalist savannah species. The conservation status of the various species and their dissimilarities in terms of threat score categories were assessed through a multivariate model following published work on African chelonian species in general. The results of this model indicate that the potentially most threatened species in Togo are Kinixys erosa, Kinixys homeana, and the 2 Cyclanorbis species (C. senegalensis and C. elegans), with Trionyx triunguis also being possibly seriously threatened. Overall, using the International Union for Conservation of Nature Red List criteria, the concurrent presence of 2 Critically Endangered (K. homeana, C. elegans), 1 Endangered (K. erosa), and several Vulnerable species shows that the chelonian fauna of Togo should be of priority relevance for the competent international agencies.
The chelonian fauna of West Africa is rich in species showing a wide range of habits and ecological characteristics (e.g., Villiers 1958; Branch 2007; Trape et al. 2012). Recently, the relevance of West African chelonians among the continental species has been pointed out at several levels and mainly in conservation terms (Luiselli 2009; Bombi et al. 2011, 2013). For instance, Luiselli (2009) considered West Africa as one of the most relevant conservation areas for chelonians in Africa on the basis of a statistical model that included both ecological (life-history) and distribution aspects of the various species of continental freshwater species. An explicit spatial modeling study showed that the Gulf of Guinea coast appeared to be an important region by all modeling analyses (Bombi et al. 2011). A similar modeling approach for all the tortoise species of Africa revealed the Gulf of Guinea as the second-most important area for the terrestrial species, with southern Africa being the most important priority area (Bombi et al. 2013). These data are also noteworthy considering that chelonians represent the most endangered group of reptiles, with over 40% of the worldwide species being endangered (Böhm et al. 2013). Thus, there is now considerable evidence that the Gulf of Guinea region is particularly important for the conservation of turtles and tortoises of Africa (Bombi et al. 2011, 2013; Böhm et al. 2013).
Among the countries along the Gulf of Guinea, Nigeria has been most intensively studied concerning the ecology and biology of turtles and tortoises (Luiselli 2003a, 2003b, 2006a, 2006b). The studies on the chelonians of the other countries mostly focused on faunistic records (e.g., Hoogmoed 1980; Rödel and Grabow 1995; Chirio and LeBreton 2007; Böhme et al. 2011) and the ecology of particular species (Rödel 1997, 1999); further data are available in a suite of more-general articles, books, and reports (e.g., Gramentz 2005, 2008; Branch 2007). In particular, there has been virtually no dedicated study on the chelonians of the Dahomey Gap, which extends from Ghana to Benin. The most up-to-date summary of West African chelonians was recently presented by Trape et al. (2012).
Intriguingly, several species of chelonians which are known to occur in the western and in the eastern forest blocks of West Africa (for instance, Pelusios niger) seem to be absent (or nearly so) from Togo and Benin, which appeared among the main “gap countries” for African tortoise and turtle research (Luiselli et al. 2012b). Togo and Benin are situated across the Dahomey Gap, which represents a natural savannah barrier for forest species that occur in the forest blocks of West and Central Africa (Luiselli et al. 2012a, 2012b).
Here, we synthesize the available data on the Togolese chelonian species, with an emphasis on distribution, ecology, and conservation, complemented by notes on the history of the zoological knowledge relative to chelonians throughout the social and cultural development of Togo. Therefore, we aim at presenting here not only a scientific but also a historical perspective on Togolese chelonians.
METHODS
Study Area
Togo is a West African country bordering the Gulf of Guinea (Fig. 1). It is made up of a long strip of land located between 6°–11°N lat and 0°–2°E long. The country stretches over 660 km from north to south. It is only 50 km wide along the coast. Its maximal width is 120 km between 7° and 8°N lat. The landscape is largely a gently undulating plain, with the exception of the “chaîne de l'Atakora,” which reaches 986 m elevation (Agou Mount). The Togolese landscape consists of a succession of various ecosystems ranging from coastal grasslands to equatorial and wet tropical forests and ending in Sudanese savannahs in the North. According to Ern (1979), the vegetation of Togo can be divided into 5 ecological zones (Fig. 1). Ecological Zone I consists of Sudanese savannahs, dry forests, gallery forests, and grasslands around temporary or permanent ponds. Ecological Zone II is made up of hills covered in part with dense dry forests and open forests. Ecological Zone III is the area of the Guinean savannahs. Ecological Zone IV corresponds to the southern part of the country; it is characterized by a wet tropical climate similar to the equatorial climate and was originally largely covered with true tropical wet forests or semideciduous forests. The remaining tropical forests of Togo are entirely situated inside Ecological Zone IV. Ecological Zone V is restricted to the littoral area; it is a strongly disturbed landscape of littoral bushes, marshy grasslands, and mangroves.
Citation: Chelonian Conservation and Biology 13, 2; 10.2744/CCB-1080.1
Historical Information
Historical data on the chelonian fauna of Togo were gathered by examining materials stored in European museums. Three museums were visited in the framework of this study: The Berlin Museum (ZMB), the Museum Nationale D'Histoire Naturelle of Paris (MNHN), and the Royal Museum for Central Africa (RMCA) in Tervuren (Belgium). The most important historical data were from the Berlin Museum due to the fact that Togo was previously a German colony. The list of the examined vouchers from Togo is given below: Pelomedusa subrufa olivacea (Schweigger, 1812): Gando, ZMB 15605; Mango, ZMB 49603–49606, 16848. Pelusios castaneus (Schweigger, 1812): Kété-Kratchi (currently in Ghana), 16544 et 49361; Kundja Konkomba, ZMB 27262; Mango, ZMB 16010, 27263 et 10009. Kinixys nogueyi (Lataste, 1886): Fada Gourma, ZMB 16013; Gando, ZMB 15003; Kundja-Konkomba, ZMB 28790 et 50163; Missahohé, 16031 et 16032; Togo, no specific locality, ZMB 16106 et 17525. Kinixys homeana Bell, 1827: Badou, MRAC 73 09 R 194. Cyclanorbis senegalensis (Duméril et Bibron, 1835): Kundja Konkomba, ZMB 49639 et 26687, Mango, ZMB 26671. Trionyx triunguis (Forsskål, 1775): Kété Kratchi (Ghana), ZMB 16545. Cyclanorbis elegans (Gray, 1829): Togo, no specific locality ZMB 16011, Kete Kratchi, ZMB 16012.
In these museums, we also achieved interviews with scientists and collection managers in order to get information on the origins of the specimens if the capture localities were not indicated on the bottles. We also examined old German literature in order to obtain additional distribution records. In this regard, it is necessary to consider that the political borders of the present Togo are not the same than those of the “colonial Togo” under Germany, with its westernmost part having been appended to Ghana (finalized in 1958).
Taxonomy and Nomenclature
African chelonian taxonomy and nomenclature are unstable and have undergone several changes in recent times (e.g., Bour and Maran 2003). Here the taxonomy and nomenclature for the species examined follow van Djik et al. (2012).
Protocol, Marine Turtles
Each of the sites was surveyed by using appropriately educated personnel that recorded the quantitative data (number of turtles seen alive on the beach or dead in the fishermen's nets, number of nests, offspring, tracks on the beaches). Quantitative surveys for marine turtles (including the recording of the number of specimens observed) were carried out during 2 distinct periods by Agbo-Zegue NGO scientists; these surveys occurred irregularly between 2002 and 2003, and on a daily basis during both daytime and at night, between September 2012 and June 2013 (Segniagbeto et al. 2013b). The following transects (“areas”) were surveyed: 1) The coastal tract included between the Ghana border and the Rondpoint de Hôtel de la Paix (6 km long). This site is known to be favorable for the nesting activities of marine turtles (Segniagbeto 2004). 2) The coastal tract between the Rondpoint de l'Hôtel de la Paix and the Port of Lomé (5 km long), where the nesting activity of marine turtles is well known to local people. 3) The tract between Gbétsogbé and Kpogan (10 km in length). 4) The tract between Kpogan and Adissen (6 km long). This site is the second-most intensely frequented place by marine turtles in Togo after area 1 (Segniagbeto 2004). 5) The tract between Adissen and the minerary port of Kpémé (8 km long). This area is also another site intensely frequented by marine turtles in Togo (Segniagbeto 2004; Segniagbeto et al. 2013c).
Protocol, Freshwater Turtles and Tortoises
Data on freshwater turtles were collected opportunistically during random surveys across the potentially suitable habitats. Fieldwork was conducted in the north of the country (Oti River) in order to collect specimens of Cyclanorbis and Pelomedusa and in the South of the country for Pelusios and Trionyx (Mono, Zio, and Haho rivers, and Lake Togo). Additional data on Pelomedusa were collected in the forest areas. Local fishermen and hunters were useful for this survey as field guides. Before the fieldwork, investigations were always conducted in the villages in order to identify the field guides. Field surveys were focused on areas of suitable freshwater turtle habitat, especially during the nighttime. Specimens were captured by using local fishing nets or fish-hooks for Cyclanorbis and Trionyx. Specimens of Pelomedusa and Pelusios were captured by searching for individuals in holes along the rivers and pools. Intensive fieldwork surveys were conducted during the PhD research period (2006 to 2009) of the first author. Additional data were gathered during the research and/or conservation project (May–June 2010 and May 2013). An important source of data was also the inspection of fishing nets used by local communities in lagoons, lakes, marshes, creeks, and rivers.
Data on tortoises were also collected opportunistically during random surveys across the potentially suitable habitats. In addition to the data collected during the PhD research project of the first author (see above), additional data were collected during specifically oriented research projects. From August to October 2010, field surveys were conducted in the forest areas of Togo (Ecological Zone IV), Aboudoulye Reserve, and Alibi community forest to complete data on tortoise species in the framework of a research and conservation project on herpetofauna or biodiversity (Leapfrog Conservation Fund and AE2D/FFEM). Some other field surveys were conducted in Tododo National Park from June to July 2009 (AGBO-ZEGUE NGO/IUCN-NL project). Specimens were collected by removing leaves and stones in the forest. Several data also came from individual turtles that were captured for domestic consumption by local people, especially in forest areas.
Tortoises and turtles were not killed or damaged on capture; instead, their morphometric data were recorded and then they were released unharmed at the same habitats. A few specimens, which were already dead at the time of examination, were collected and preserved, including the following: P. s. olivacea (Schweigger, 1812): Sabiegou, GHS-W 0526, Ponio, GHS-W 1877; P. castaneus (Schweigger, 1812): Gbowle, GHS-W 1876; C. senegalensis (Duméril et Bibron, 1835): Mangon GHS-W 1906–1907.
Our data on the freshwater turtles and tortoises were completed by visiting reptile farms in Lome, also under the auspices of the Office in charge of the Wildlife (Direction de la Faune et de la Chasse).
Statistical Analyses
The dissimilarity between species in terms of their ecological distribution (i.e., their respective presence/absence in each of the 5 ecological zones of Togo) was explored by cluster analysis, using Ward's method, with 40 bootstraps as branching measurements.
In order to make a preliminary exploration of the conservation status of Togolese chelonians in the absence of sound field data on population trends, we followed a theoretical approach established by Andreone and Luiselli (2000), Filippi and Luiselli (2000), and Luiselli (2009). This approach is particularly valuable when it is necessary to assess the conservation threats of regional faunas with a scarce data set being available (Filippi and Luiselli 2000). A set of variables among those which affect the survival of turtle populations was used to characterize each species, at the scale of Togo. These variables were classified into categories ranging from 0 (least risk) to 3 (highest risk). The variables were 1) extent of occurrence in Togo (sensu International Union for Conservation of Nature [IUCN] criteria, available at www.iucnredlist.org/documents/RedListGuidelines.pdf); 2) ecological niche width; and 3) level of human harvesting.
The scores for extent of occurrence in Togo were the following: score = 1: species occurring in > 70% of the country; score = 2: species occurring in 30%–69.9% of the country; score = 3: species occurring in < 30% of the country. For ecological niche width, score = 1: species occurring in more than 3 ecological zones; score = 2: species occurring in more than 2 ecological zones; score = 3: species occurring in 1 or 2 ecological zones. For level of human harvesting, score = 1: species occurring occasionally as a subsistence food, or as a fetish, or as an animal used for the pet trade; score = 2: species occurring occasionally as a subsistence food, or as a fetish, but frequently as an animal used for the pet trade or vice versa; score = 3: species occurring frequently as a subsistence food, as a fetish, and as an animal used for the pet trade.
All score attributions are founded on an expert-based assessment made by G.H. Segniagbeto, L. Luiselli, and F. Petrozzi on the grounds of their field research. The sum of the scores for each of the 3 variables represented the overall threat score level for the given species in the territory of Togo. Concerning the use of these 3 variables, it should be noticed that Luiselli (2009) used 6 independent (or moderately interdependent) variables to obtain his scores, whereas we used here only 3 variables. This difference may have oversimplified our assessments, thus producing some potential inconsistencies between species in terms of their overall risk assessment. The dissimilarity among species in terms of their threat category scores were studied by cluster analysis (see above). All statistical analyses were performed using Past software.
SPECIES STATUS
Historical Perspective of the Studies of Togolese Chelonians
The year of first mentioning of chelonian species for Togo is presented in Table 1. According to this table, 9 of 13 species were first cited to occur in Togo between the last decade of the 1800s and first decade of the 1900s, i.e., during the colonial age. Cyclanorbis elegans was recorded in 1957 just before the end of the colonial period, and two marine turtle species (Chelonia mydas, Lepidochelys olivacea) were recorded well after the independence of the Togolese Republic.
Indeed, the earliest studies of the reptile fauna of Togo date back to the time of the German colonisation (Werner 1898, 1899, 1902, 1929; Sternfeld 1908a, 1908b, 1909), but were essentially devoted to snakes (but see Matschie 1893; Tornier 1901 for some data on chelonians).
After the period of pioneering research on Togolese reptiles of the late 19th and early 20th century, there were no more studies until years from the 1930s to the 1960s, when the snake fauna of Togo was still the prominently studied reptilian issue (e.g., Loveridge 1939, 1940, 1944, 1958), but with a few records for chelonian species as well (Loveridge and Williams 1957). In the 1970s, 3 Belgian field missions (Hulselmans and Verheyen 1970; Hulselmans et al. 1971) investigated the reptile fauna of Togo, reporting also some additional distribution data on the chelonian species.
More recently, the population status and abundance of marine turtles was studied by Segniagbeto (2004) and by Segniagbeto et al. 2013b). Freshwater and terrestrial chelonians remained unstudied in the wild, but useful data on their ecology, reproduction, and distribution were provided by a few studies primarily devoted to investigating the characteristics of the reptile farms and the intensity of the international pet trade (Harris 2002; Ineich 2011). For the moment, the scientific knowledge of the ecology and demography of Togolese populations of turtles and tortoises remains at an embryonic stage, although some projects (by L. Luiselli, F. Petrozzi, and G.H. Segniagbeto) have been initiated.
Checklist of the Species, Their Habitats, and Local Distribution
At present a total of 13 chelonian species are known to occur in Togo (Fig. 2). A summary of their distribution, natural history, and conservation status is given below.
Citation: Chelonian Conservation and Biology 13, 2; 10.2744/CCB-1080.1
Cheloniidae Oppel, 1811. – Three species of Chelonidae are known to occur along the Togolese coasts.
Chelonia mydas (Linné, 1758)
Distribution and Historical Records
This species was collected across the entire coast of Togo (Stuart and Adams 1989; Stuart et al. 1990; Fretey 2001; Segniagbeto 2004; Bowessidjaou et al. 2006; Fretey et al. 2007): Agbodrafo, Gbétsogbé, Kodjoviakopé, Aného. This species appeared to be particularly frequent from Gbétsogbé to Agbodrafo (Segniagbeto 2004; Segniagbeto et al. 2013a) and was also found occasionally in the fetish market of Lomé (Segniagbeto et al. 2013c).
Natural History
Between 2002 and 2003, a total of 105 individuals (including adult males and adult females as well as juveniles and subadults) were recorded along 50 km of the Togolese coast (Segniagbeto 2004). Between September 2012 and June 2013, along a strip of 35 km, 206 individuals were recorded including males (n = 72) and females (n = 134) (Segniagbeto et al. 2013b). No evidence of egg-laying was found along the coast of Togo. Indeed, this marine species seems to use the Togolese waters only for foraging (Fretey 2001; Segniagbeto et al. 2013c).
Conservation
The number of individuals captured in the fishing net (315 individuals from September 2012 to August 2013) suggests that incidental fisheries catches may considerably affect the wild populations of C. mydas. The importance of juveniles and subadults (182 individuals) in this sample would indicate that the Togolese coast constitutes an important foraging habitat for this species in the Gulf of Guinea. The Togolese coast is characterized by the presence of beach-rock where algae are developed. In this case, fishing activities in the coastal waters seriously impact the population of this species. The number of the dead animals recorded during the same period was also high (n = 52 individuals). In addition to the incidental catches, heavy traffic by ships and boats outside the large Lomé port can also impact the population of this species. Hence, it is urgent to undertake conservation measures for the preservation of the population of this species in Togo.
Eretmochelys imbricata (Linné, 1766)
Distribution and Historical Records
This species was first cited to occur in Togo by Boulenger (1905), and several authors later confirmed its presence without giving precise capture sites (e.g., Loveridge and Williams 1957; Villiers 1958; Stuart and Adams 1989; Stuart et al. 1990; Bowessidjaou et al. 2006). Formia (in Frétey 2001) recorded the presence of juveniles in the Togolese waters. However, Eretmochelys imbricata is not mentioned as occurring in Togo by Fretey et al. (2000). This species was recorded in the following localities: Afidenyigban, Agbodrafo, Gbetsogbé.
Natural History
Eretmochelys imbricata does not breed on the Togolese coasts (Segniagbeto 2004; Segniagbeto et al. 2013a). Because many of the individuals captured in Togo were juveniles, it is supposed that they came from Bioko island (Equatorial Guinea) where this species is known to breed (e.g., Fretey 2001). Three individuals were recorded between September 2002 and April 2003 (Segniagbeto 2004), but the species was not recorded in the 2012–2013 surveys (Segniagbeto et al. 2013b).
Conservation
This species is very rare in Togo, but carapaces belonging to this species are regularly sold as souvenirs in the artisanal market in Lomé or along the coastal villages.
Lepidochelys olivacea (Eschscholtz, 1829)
Distribution and Historical Records
There were no records for the presence of this species in Togo until recent times. It was recorded in the following localities: Agbodrafo, Gbetsogbé, Kodjoviakopé, Kotokoukondji, Ablogame, Avepozo, Kpogan, Devikinme, Adissen, Djeke, Aneho.
Natural History
Lepidochelys olivacea nests on the Togolese beaches (Formia in Fretey 2001; Bowessidjaou et al. 2006). Segniagbeto (2004) and Segniagbeto et al. (2013a, 2013b) reported that 72 nests were found between Lomé and Grand Popo (Bénin). However, no juveniles were recorded in waters. The nesting season extends from September to February, but some sporadic nests can be observed in April, May, and June. From September 2012 to June 2013, 352 individuals of this species were recorded including 45 males and 307 females (Segniagbeto et al. 2013b). During the same period, a total of 46 nests were detected (Segniagbeto et al. 2013b). The presence of several adult males in the fishing nets suggests that the Togolese waters are also mating areas for this species.
Conservation
Lepidochelys olivacea is the most common marine turtle species in the Gulf of Guinea (Fretey 2001) and is also very common along the entire coast of Togo. This species is not currently threatened in the country. However, females of this species are routinely killed by fishing activities: 96% of the total dead individuals (n = 143) recorded from September 2012 to August 2013 were indeed females.
Dermochelyidae Fitzinger, 1843. – This family includes only 1 species that is also found in Togo.
Dermochelys coriacea (Vandelli, 1761)
Distribution and Historical Records
This species was firstly cited for Togo by Matschie (1893) and Tornier (1901) based on 3 embryos from Sebbe (Zébé, currently Aného). This record was re-used by Loveridge and Williams (1957), Brongersma (1981–1982), and Stuart and Adams (1989). More recently, the presence of this species in Togo was confirmed by Fretey (2001), Fretey et al. (2007), and Bowessidjaou et al. (2006). Dermochelys coriacea was recorded during our studies in the following localities: Agbodrafo, Kotokoukondji, Ablogame, Agbodan, Devekinme, Avepozo, Gbodjme, Agbavi.
Natural History
This species nests on the Togolese beaches. Segniagbeto (2004) found 27 nests between September 2002 and February 2003. From September 2012 to June 2013, 17 individuals were recorded along the coast. During this period 4 nests were recorded (Segniagbeto et al. 2013b).
Conservation
This species is relatively protected in Togo. Because of its huge size, it is generally difficult for coastal people to kill any individual without the awareness of the public and the agents of the Office in charge of wildlife. Therefore, nearly all of the individuals captured at the beaches or in the fishing nets were released at the sea.
Pelomedusidae Cope, 1868. – From this family, 3 species were confirmed to occur in Togo, with 1 being possibly extinct in the country.
Pelomedusa subrufa (Bonnaterre, 1789)
Distribution and Historical Records
This species was firstly mentioned to occur in Togo by Tornier (1901), at the locality of Mango, in the north of the country. The presence of Pelomedusa subrufa is currently documented from the following localities: Gando, Mango, Sabiegou, Kpalimé, Togoville, Lomé, Tovegan, Kolo, Avetonou, Azahoun.
This species is widespread across Togo. The areas where it appeared to be particularly abundant were, for Ecological Zone I, the Oti River (mountain dry savannah habitat); in Ecological Zone II, the Oti River (Sudanese savannah with woodlands and dry forest); in Ecological Zone III, Mono River (Guinea savannah with dry forest); in Ecological Zone IV, Womé, Missa-hohé forest, Kpélé and Badou areas; and in Ecological Zone V, the Togodo forests and wetlands around the Mono River and Guinea savannah along the coast. These relative abundance data were gathered by both trapping results and interviews with local people.
Natural History
In Togo, P. subrufa inhabits mostly marshlands and temporary ponds and may be found in water bodies situated also inside the forest; for instance in the surroundings of Kpalimé. It has a mainly carnivorous diet (Rödel 1997; Luiselli et al. 2011).
Conservation
This species is intensively harvested for the pet trade, and they are exploited in the international pet trade. According to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) database, 3072 live individuals were exported between 2001 and 2005. In addition, this species was traded for fetish in the Lomé market (Segniagbeto et al. 2013c). However, P. subrufa is widespread and locally abundant and is not under threats at the country scale.
Pelusios castaneus (Schweigger, 1812)
Distribution and Historical Records
Pelusios castaneus is, together with P. subrufa, the most common freshwater turtle in the country (Segniagbeto et al., unpubl. data). It was first cited to occur in Togo by Tornier (1901) in the localities of Mango, Bismarckburg (near Yégué, Sotouboua prefecture), and Kété Kratchi (currently in Ghana). This species was recorded, during the present study, in the following localities: Kundja Konkomba; Mango; Kelekougan; Agoegan; Agbanakin; Djagble; Dekpo; Sevagan; Adamé; Togoville and Lake Togo; Togodo National Park.
A neotype was designated for Emys castanea Schweigger, 1812 from Togo by Bour (2008); indeed, the selected specimen is registered as MNHN 2008.0303; the type locality is “vicinity of Koutchatcha” (lat 7°20′N, long 1°18′E), a village close to the Amou River (∼30 km East of Gléï), Ogou Prefecture, Plateaux Region, *Togo*” (Bour 2008).
Natural History
Pelusios castaneus is present across most habitats in Togo; although it can be found in ponds and extended marshlands (for instance at the border of Lake Togo), it inhabits rivers and streams more frequently than does P. subrufa (compare Rödel and Grabow 1995). It can also be observed inside forest.
Conservation
This species is intensively harvested for the pet trade. According to the CITES database, 3244 live individuals were exported between 2001 and 2005. In addition, this species was traded for fetish in the Lomé market (Segniagbeto et al. 2013c). However, this species is widespread and locally abundant, and is not under threats at the country scale.
Pelusios niger (Duméril & Bibron, 1835)
Distribution and Historical Records
This freshwater turtle has also been implicitly or explicitly included in the Togolese fauna by previous authorities. It was explicitly included by King and Burke (1989), Iverson (1992, map) and Bonin et al. (1996, map). Pelusios niger was implicitly included because its range was reported as extending from “Ghana eastward to Cameroon” by Ernst and Barbour (1989), “von Gambia an südwärts bis Angola” by Wermuth and Mertens (1977), “Liberia and Ghana east through coastal West Africa to southern Cameroon and Gabon” by Welch (1994), and “Sierra Leone und Liberia bis Gabun” by Rogner (1996). The description of the related species Pelusios cupulatta by Bour and Maran (2003) added to this confusion: for instance, Vetter (2011, map) included both species as being present in Togo. Turtles identified as P. niger are also sold from time to time as exports from Togo (Bour, pers. obs.), but they could be possibly imported from a neighbouring country. On the other hand, according to museum specimens, both species are actually present on either side of the “Dahomey gap”, precisely the Ivory Coast and Nigeria for P. cupulatta and Benin, Nigeria, and Ghana for P. niger (Bour and Maran 2003). This is another evidence of a former connection through Togo (as are the remaining populations of forest Kinixys spp.).
However, the only examined specimen with a rather precise locality is a male P. niger, of 230 mm carapace length (ZMH R03862), from the neighbouring Lama Kara, Kara (∼ lat 9°30′N, long 1°10′E), in the Zoologisches Museum Hamburg. The general landscape of the Kara region is quite dry (relatively arid Guinea savannah), with no closed forest remaining. Our hypothesis is that P. niger may be actually extirpated from Togo, although it cannot be excluded that a few isolated populations of Pelusios with a “hooked beak” still remain in some remote and wet parts of the country. In the case of the Kara record, it is likely that the species occurred in rivers with former gallery forest, as it has been observed that many rainforest amphibian and reptile species manage to occur far north in west Africa by making use of rainforest-like conditions in rivers with wide gallery forests (for the case of Mali and Burkina Faso, see Böhme et al. 1996).
Natural History
No data are available for this species in Togo, whereas it has been studied intensely in Nigeria (e.g., see Luiselli et al. 2004, 2006a, 2006b).
Conservation
Probably highly endangered, if still occurring in Togo. No data are available on its conservation status at the country scale.
Testudinidae Batsch, 1788. – This family includes 3 native species in Togo.
Kinixys nogueyi (Lataste, 1886)
Distribution and Historical Records
Kinixys nogueyi is the most widespread tortoise species in Togo. It was first recorded for this country by Matschie (1893) and Tornier (1901) from the localities of Bismarckburg, Fada Gourma ( = Fada-Ngourma, now in Burkina Faso), and Missahohé. During the investigations for the present paper, this tortoise was recorded in the following localities: Kpalimé, Agbandji, Gando, Kundja-Konkomba, Missahohé, Kouvé, Tomety-Kondji.
Natural History
Although K. nogueyi inhabits primarily bushlands in the Guinea savannah region, this species can also be observed in the forest zone where it inhabits clearings and secondary forest patches. In Kpalimé, it occurs sympatrically (or in contiguous parapatry) with the 2 forest congeners, Kinixys erosa and K. homeana.
Conservation
Kinixys nogueyi is heavily harvested for the pet trade. According to the CITES database, a total of 14,614 live individuals were exported from Togo between 2001 and 2005. In addition, this species was the most frequently traded tortoise species in the fetish market of Lomé (Segniagbeto et al. 2013c). However, this species is widespread and is not under threats at the country scale, despite being declining in most regions of West Africa (and hence assessed as Vulnerable by IUCN/SSC TFTSG in the Lomé workshop, August 2013).
Kinixys erosa (Schweigger, 1812)
Distribution and Historical Records
This species was first recorded in Togo by Matschie (1893) and later by Loveridge and Williams (1957) and Harris (2002). During the present investigations, K. erosa was recorded only from the forest of Badou, Diguengue, Assokoko, Kpadapé, and Hanyigban.
Natural History
Kinixys erosa is a forest specialist. In most forest sites, it occurs in sympatry with K. homeana, and around Kpalimé also with K. nogueyi.
Conservation
Kinixys erosa is seriously threatened due to restricted distribution, habitat loss, and human harvesting (Luiselli 2003a). This species was found in the fetish market of Lomé (Segniagbeto et al. 2013c) and was also traded as a pet: according to the CITES database, 425 live specimens were legally exported from Togo between 2001 and 2005. All the specimens exported from Togo were captured from sites within Ecological Zone IV (hilly rainforest). Henceforth, wild individuals of this species cannot be exported from Togo anymore (this regulation started in 2013). The K. erosa species is heavily declining in most regions of West Africa (and hence assessed as Endangered by IUCN/SSC TFTSG in the Lomé workshop, August 2013).
Kinixys homeana Bell, 1827
Distribution and Historical Records
Kinixys homeana was firstly mentioned to occur in Togo by Matschie (1893) and later by Loveridge and Williams (1957) and Harris (2002). During the present investigations, K. homeana was observed only in Badou, Tomegbe, Akloa, Kpadapé, and Hanyigban. In Togo, this rare species is restricted to Ecological Zone IV (hilly rainforest).
Natural History
This species is a forest specialist that, in most forest sites, occurs in sympatry with K. erosa and around Kpalimé also with K. nogueyi.
Conservation
Kinixys homeana is seriously threatened due to tremendous habitat loss in its restricted range as well as to human harvesting (Luiselli 2003a; Luiselli and Diagne 2013). All the specimens exported from Togo were captured from sites within Ecological Zone IV (hilly rainforest). Harris (2002) and Maran and Serpol (2006) studied the mechanisms of the tortoise collections for the pet trade, especially around Kpalimé. According to the CITES database, 9836 live specimens were exported from Togo between 2001 and 2005. This species is heavily declining in wide regions of West Africa (and hence assessed as Critically Endangered by IUCN/SSC TFTSG in the Lomé workshop, August 2013; Luiselli et al. 2006c; Luiselli and Diagne 2013).
Trionychidae Gray, 1825. – This family includes 3 native species in Togo.
Cyclanorbis elegans (Gray, 1869)
Distribution and Historical Notes
The presence of this species in Togo has been suspected for a long time; however, without a verified country record. During our investigations we never recorded any live specimen, but one specimen of C. elegans, deposited in the Zoological Museum of Berlin (Germany) (voucher ZMB 16011), is labelled as coming from “Togo”, unfortunately without precise locality. Another specimen (ZMB 16012), labelled as coming from Kete-Krachi, Togo, was indeed captured in a locality that is now in Ghana. In addition, the species is known to occur at Sansanné-Mango (lat 10°21′N, long 0°28′E) along the Oti River in Togo (see also Loveridge and Williams 1957, as they gave Kete Krachi [see above] and Mango [idem] as Togolese localities, as well as Yendi, which is also currently located in Ghana). It is probably these museum specimens which Gramentz (2008) and Trape et al. (2012) referred to.
Natural History
Nothing known concerning the Togolese populations.
Conservation
This is probably an extremely threatened species, but not observed in the fetish market of Lomé (Segniagbeto et al. 2013c). This species is apparently heavily declining in wide regions of West Africa (and hence assessed as Critically Endangered by IUCN/SSC TFTSG in the Lomé workshop, August 2013).
Cyclanorbis senegalensis (Duméril & Bibron, 1835)
Distribution and Historical Records
This species was recorded for the first time in Togo by Tornier (1901) from the localities of Kété Kratchi and Mango (voucher in Berlin museum: ZMB 26671). Iverson (1992) reported its presence in northern Togo. During the present surveys, we recorded this species in the following localities: Kundja Konkomba (a locality already listed by Loveridge and Williams 1957), Mango, Mandouri.
Natural History
All recorded specimens were found in Ecological Zone I, but interviews with local people of the Kara region suggested that this species is almost certainly also present in Ecological Zone II, although it has not yet been collected. In neighbouring countries it has been most frequently found in rivers and ponds (in the latter, only juveniles) within the Guinea and Sudanese savannah zones (e.g., Rödel and Grabow 1995; Gramentz 2008; M.-O. Rödel, unpubl. records for Bénin).
Conservation
The conservation status of C. senegalensis in Togo is presently unknown, but apparently the species has been experiencing a population decrease, as suggested by our unpublished interviews with reptile collectors and exporters for the pet trade. No live specimen was exported from Togo between 2001 and 2005, and very few specimens were exported after that period, thus showing that this species is not of high interest for the international pet trade. In the past, this species has been exported under the name of T. triungius. Thus, it is difficult to evaluate the true number of live specimens that were exploited in the pet trade. Currently, our data reveal that more than 50 individuals are exported per year from Togo.
This species was also traded in the fetish market of Lomé (Segniagbeto et al. 2013c). Although not under immediate risk of extinction, it is threatened at the country scale. This species is declining in West Africa (and hence assessed as Vulnerable by IUCN/SSC TFTSG in the Lomé workshop, August 2013).
Trionyx triunguis (Forskål, 1775)
Distribution and Historical Records
This species was cited for the first time to occur in Togo by Matschie (1893) and Tornier (1901). However, these authors reported its presence in Kété Kratchi, which is currently situated in Ghana. During the present surveys, this species was found in the Sokodé area, and another specimen reportedly originating from Togo was observed at a reptile farm located in Lomé.
Natural History
The ecology of T. triunguis is virtually unknown in Togo, but interviews with reptile traders suggest that it should be extremely rare in the entire country, with very low density even in its primary habitat (rivers and coastal mangroves). Overall, it is very likely that the species actually in West Africa occurs only in large rivers and the sea.
Conservation
No live specimen was exported from Togo between 2001 and 2005, neither was it observed in the fetish market of Lomé (Segniagbeto et al. 2013c). Trionyx triunguis is threatened at the country scale. The West African populations of this species are heavily declining, and overall this species was assessed as Vulnerable by IUCN/SSC TFTSG in the Lomé workshop, August 2013.
SUMMARY
Ecology
The ecological distribution of the terrestrial and freshwater chelonians, based on their occurrence across the 5 ecological zones of Togo, is synthesized in Table 2. We excluded from this table (and successive analysis) P. niger because of too scarce information available for its presence in Togo. A dendrogram (Fig. 3) showed that 3 main clusters of species are formed: a) 1 cluster consisted of T. triunguis, K. homeana, and K. erosa; b) another cluster consisted of the 2 Cyclanorbis species; and c) a third cluster consisted of the 2 Pelomedusidae species and K. nogueyi. Cluster (a) includes species that can be considered “forest-associated” species in West Africa. However, whereas the forest preferences for the 2 Kinixys species appear obvious (e.g., Luiselli et al. 2000; Luiselli and Diagne 2013), for T. triunguis it is necessary to make some additional considerations. Trionyx triunguis populations are not typical of forest water bodies in eastern Africa (Branch 2007), and their occurrence in the Togolese ecological zones does not confirm the pattern of “forest” organisms as they occur in Zone III (Guinea savannahs) and Zone V (littoral bushes, marshy grasslands, and mangroves). Trionyx triunguis lives in huge rivers and in the sea; in the Mediterranean region it is known that the population constantly swims from, for example, the Nile to southern Turkey and back, and in Nigeria they are found in the bigger rivers of the Niger Delta and in the Cross River (Luiselli et al. 2000). Hence, it is only clustering in the forest zone (together with K. erosa and K. homeana) because the forest zone is the area where rivers are largest and close to the sea and because all these species are neither Sudanese savannah nor generalist savannah species. Cluster (b) consists of Sudanese savannah species, and cluster (c) of generalist savannah species.
Citation: Chelonian Conservation and Biology 13, 2; 10.2744/CCB-1080.1
In terms of elevation, the species which can reach the highest altitudes are K. homeana and K. erosa, which inhabit montane forests up to over 800 m a.s.l. (Kpalimé area in southwestern Togo). However, most of the chelonian species are typical lowland dwellers.
Marine Turtle Conservation
Since 1999, the Togolese Republic agreed with the international protocol of CMS/PNUE (Convention on Migratory Species/United Nations Environmental Programme), which is scheduled to save the marine turtles of the African Atlantic coast, and also adhered with all the major international conservation agreements including, for example, the Convention on Biological Diversity (CBD), the Convention sur la Conservation des Espèces migratrices appartenant à la faune sauvage (CMS), the Convention internationale sur le Commerce des Espèces de Flore et de Faune sauvages menacées d'extinction (CITES), and so forth. In addition, the marine turtles and their habitats are protected in Togo as a fulfillment of the indications of the IUCN Red List, which considers all marine turtle species, and especially D. coriacea and E. imbricata, as Critically Endangered (CR). Nonetheless, as for the marine turtles, the most threatened species in Togo is certainly L. olivacea, which is listed as Vulnerable (VU) by IUCN (www.iucnredlist.org; accessed 2 August 2013).
Unfortunately, our data show that accidental capture is a serious threat for the Togolese populations of marine turtles. For instance, in our sample of recorded individuals (n = 575), 308 (53%) were accidentally captured by fishermen. Although many of them were released without being killed (n = 226), several other individuals died. In addition, between September 2012 and June 2013, 158 turtle corpses (i.e., 27% of the total records) were found along the beaches, probably killed by boats and ships entering the Lomé port and also dying in the fishermen's nets (these animals are drowned and rot in the nets, so they cannot be eaten by the local population, and hence the fishermen will release the corpse in the sea without taking care of it after accidental capture; Segniagbeto 2004; Segniagbeto et al. 2013b).
Freshwater and Terrestrial Turtle Conservation
Based on our unpublished data, it seems that only 2 species can reach high local densities (higher than 50 individuals per hectare), i.e., P. subrufa and P. castaneus (in Togodo National Park, along the marshes and main tract of the Mono River). Kinixys nogueyi is widespread, but we never observed high densities at a site, and all the other species showed a scattered distribution and were uncommon or very rare at each site.
The scores for the various terrestrial and freshwater chelonian species native to Togo, and based on the model proposed by Luiselli (2009), are reported in Table 3. We excluded from this table (and successive analysis) P. niger because of too scarce information available for its conservation status in Togo. Based on the total score criterion, the potentially most threatened species in Togo should be K. erosa, K. homeana, and the 2 Cyclanorbis species, all being ranked by our model with a total score of at least 7. Indeed, our multivariate model clustered together these 4 species (although with T. triunguis, see Fig. 4), whereas the other cluster (showing the species with low scores for the given variables, i.e., the species with low threat potential for each of the examined variables) consisted of the 2 Pelomedusidae species and of K. nogueyi (Fig. 4).
Citation: Chelonian Conservation and Biology 13, 2; 10.2744/CCB-1080.1
The results of our multivariate model are in relatively good agreement with indirect information also collected from reptile traders who have a long experience in the professional field searching for turtles and tortoises in Togo. Indeed, it should be remembered that the reptile pet trade business has been operative in Togo for at least 30 yrs (Harris 2002) and that it appeared to be ecologically sustainable for at least some species (notably Python sebae and Python regius, see Luiselli et al. 2012a). Nonetheless, there is an urgent need for demographic studies on wild populations of K. erosa and K. homeana in Togo because these species are in decline in most of West Africa (Luiselli et al. 2006c) and have been experiencing a population collapse in Nigeria (Luiselli et al. 2013). In Togo, the deforestation rate is high (about 5.75%, i.e., 20,000 ha per year between 2005 and 2010 [FAO 2010]), and hence habitat loss seems to be a major threat for the remaining populations of these forest species. Indeed, K. homeana has recently been evaluated as Critically Endangered and K. erosa as Endangered by IUCN/SSC TFTSG (Lomé, August 2013). Concerning the other Togolese species, at the same IUCN/SSC workshop 3 (K. nogueyi, T. triunguis, and C. senegalensis) were assessed as Vulnerable and another (C. elegans) as Critically Endangered. In our study, however, the total scores obtained by our expert-based approach are not proportional to the threat category evaluated by IUCN/SSC TFTSG. In particular, C. elegans is not recognized by our analysis as 1 of the 2 most threatened species, and K. nogueyi is classified as 1 of the species with low threat potential for the examined variables. This poor agreement could be due to the low number of variables considered here given that, in Luiselli's (2009) model, 6 variables were used instead and, hence, his model was certainly stronger than ours.
Because of the concurrent presence of 2 Critically Endangered species, 1 Endangered species, and several Vulnerable species, the chelonian fauna of Togo must be considered of priority relevance by the competent international agencies (see also Bombi et al. 2011, 2013 for spatial modeling showing the same evidence).
Map of Togo showing the main vegetation zones and the sites of chelonian records. Ecological Zone (EZ) I: 1 = Mandouri, 2 = Mango, 3 = Sabiegou, 4 = Gando, 5 = Kundja Konkomba (Guerin Kouka). EZ II: 6 = Kara, 7 = Sokodé. EZ III: 8 = Agbandji, 18 = Avetonou. EZ IV: 9 = Diguengue, 10 = Assokoko, 11 = Badou, 12 = Tomegbe, 13 = Akloa, 14 = Missahohé, 15 = Kpalimé, 16 = Hanyigban, 17 = Kpadapé. EZ V: 19 = Tovegan, 20 = Azahoun, 21 = Kouvé, 22 = Tomety-Kondji (Togodo National Park), 23 = Togoville, 24 = Kolo, 25 = Sevagan, 26 = Dekpo, 27 = Djagble, 28 = Kelekougan, 29 = Agbanakin, 30 = Adamé, 31 = Agoegan, 32 = Aného, 33 = Agbodrafo (Djeke, Adissen), 34 = Devikinme (Gbodjme, Agbavi, Afidenyigban), 35 = Avepozo (Kpogan), 36 = Lomé (Gbétsogbé, Ablomgame, Kotokoukondji, Kodjoviakopé). EZ I = Sudanese savannah; EZ II = hilly dry open forest; EZ III = Guinean savannah; EZ IV = wet forest and semi-deciduous forest; EZ V = littoral bush, marshy grassland, and mangrove.
Nine of the 13 species of Togolese chelonians (all photos refer to specimens captured in Togo): (a) Chelonia mydas, (b) Dermochelys coriacea, (c) Kinixys nogueyi, (d) Kinixys erosa, (e) Kinixys homeana, (f) Pelomedusa subrufa, (g) Pelusios castaneus, (h) Cyclanorbis senegalensis, (i) Trionyx triunguis.
Dendrogram showing the dissimilarities among species regarding their ecological distribution (presence/absence) across the 5 ecological zones of Togo.
Dendrogram showing the dissimilarities among species regarding the potential threat categories assessed according to the model of Luiselli (2009). For more details, see the text.
Contributor Notes
Handling Editor: Jeffrey A. Seminoff
