Segniagbeto_etal_luiselli_population_structure_in_turtles_from_togo_HerpetoZoa.qxd 28.07.2015 14:56 Seite 1 HerpetoZoa 28 (1/2): 29 - 38 29 Wien, 30. juli 2015 Sex ratio, size structure and morphometrics of turtle populations from togo, West africa (testudines: testudinidae, pelomedusidae) Geschlechterverhältnis, Größenverteilung und morphometrische Merkmale in Schildkrötenpopulationen aus togo, Westafrika (testudines: testudinidae, pelomedusidae) GaBrIel H. S eGnIaGBeto & k oMal aFIaDeMaGno & G oDFrey C. a kanI & F aBIo petroZZI & l uCa luISellI kurZFaSSunG Studien grundlegender populationsbiologischer aspekte wie Geschlechterverhältnis und Größen- bzw. altersaufbau sind wesentliche Voraussetzung bei der erarbeitung von Schutzprogrammen gefährdeter arten. aller - dings sind nur wenige derartige arbeiten verfügbar, was afrikanische land- und Süßwasserschildkröten betrifft. Die autoren untersuchten das Geschlechterverhältnis, und den Größen- bzw. altersaufbau bei populationen von Kinixys homeana Bell , 1827, Pelomedusa cf. subrufa (Bonnaterre , 1789) [wahrscheinlich P. variabilis petZolD et al., 2014 oder P. olivacea (S CHWeIGGer , 1812)] und Pelusios castaneus (SCHWeIGGer , 1812) und berichten zuge - hörige morphometrische Daten (panzermaße, körpermasse). Die untersuchten populationen waren untereinander ähnlich, was das Ge schlechterverhältnis (nahe 1:1) und den geschlechtsbedingten Größenunterschied (nicht signi - fikant) betrifft, unterschieden sich aber auffällig in ihrem Größen- bzw. altersaufbau. In den populationen von K. homeana waren weder jungtiere noch erwachsene von voller Größe festzustellen. Im Gegensatz dazu wiesen die populationen der beiden aquatischen Schildkrötenarten beträchtliche anteile an jungtieren und Subadulten auf. Diese Größen verteilungen werden als zahlenmäßiger rückgang in den populationen von K. homeana und als arter - haltende Vermehrungsrate bei den zwei pelomedusenarten interpretiert. aBStraCt Studies on the basic aspects of population biology, including, e.g., sex ratio and size or age structure, are important for designating management programs for threatened species. nonetheless, very few studies of this type are available as for the african tortoises and turtles. the authors studied sex ratio and size structure of togolese populations of Kinixys homeana Bell , 1827, Pelomedusa cf. subrufa (Bonnaterre , 1789) [probably P. variabilis petZolD et al., 2014, or P. olivacea (S CHWeIGGer , 1812)] , and Pelusios castaneus (SCHWeIGGer , 1812), and report corresponding morphometric data (shell measurements, body mass). all the studied populations were similar in terms of both sex ratio (close to 1:1) and sexual size dimorphism (not significant), but differed remarkably as for their overall size structure. Kinixys homeana showed a population profile in which neither juveniles nor full-grown adults were observed. In contrast, the population profiles of the two aquatic species revealed a considerable pro - portion of juveniles and subadults. these patterns are interpreted as a signal of decline for the population of K. homeana and sustaining populations as for the two aquatic pelomedusidae. key WorDS reptilia: testudines: testudinidae: Kinixys homeana , Kinixys erosa , Kinixys nogueyi ; pelomedusidae: Pelo - medusa cf. subrufa , Pelomedusa olivacea , Pelomedusa variabilis , Pelusios castaneus , Cyclanorbis senegalensis ; sex ratio, body size, shell morphology, population biology, ecology, pet trade, conservation; togo, West africa IntroDuCtIon Documenting basic aspects of popula - niles along with few very old individuals tion biology may be important for under - has been interpreted as a signal of increas - standing population trajectories and even ing population size or of a population that designing accurate management plans for has not suffered any recent catastrophes the conservation of target species (e.g., (FIlIppI et al. 2010), whereas the opposite is BjornDal 1982; StuBBS et al. 1985 ). In not correct due to methodological problems chelonians, the presence of numerous juve - of detecting juveniles (see e.g., pIke et al. Segniagbeto_etal_luiselli_population_structure_in_turtles_from_togo_HerpetoZoa.qxd 28.07.2015 14:56 Seite 2 30 G. H. S eGnIaGBeto & k. a FIaDeMaGno & G. C. a kanI & F. p etroZZI & l. l uISellI 2008) . Moreover, StuBBS et al. (1985) and the genera Kinixys (testudinindae), Pelusi - HaIley (2000) showed that catastrophic os , Pelomedusa (pelomedusidae) and Cyc - events (such as fires) negatively affected lanorbis (trionychidae) were collected, juveniles much more than adults. focus was put on three species from which Concerning african tropical chelonian the most data was recorded, i.e., Kinixys ho - species, there are just very few studies doc - meana Bell , 1827 , Pelomedusa cf. subrufa umenting even basic aspects of population (Bonnaterre , 1789) [prob ably Pelomedusa biology of single populations, and this variabilis petZ olD , V arGaS -r aMIreZ , k eHl- scarcity of data may be detrimental to con - MaIer , V aMBerGer , B ranCH , D u preeZ , servation actions, especially if we take into HoFMeyr , S CHleICHer , Š Iroký & F rItZ , account that african turtles and tortoises are 2014, or Pe lomedusa olivacea (S CHWeIG- seriously threatened at a continental-wide Ger , 1812) ], and Pelusios castaneus scale ( luISellI 2009; BoMBI et al. 2012 , (SCHWeIGGer , 1812) . the taxonomic status 2013). of togolese Pelomedusa is still uncertain. In this paper, the authors present field Pelomedusa variabilis was described on the data on some aspects of the population biol - basis of specimens from neighboring Ghana ogy of a few chelonian species from two and Ivory Coast and Pelomedusa “lineage major vegetation zones of the Guinean for - III” [ olivacea ] sensu petZolD et al. (2014) est-savannah mosaic, of togo (West africa). from adjacent Benin and Burkina Faso. the although data on five species belonging to authors refrain from assigning the reported Pelomedusa turtles to one of those species and will use the name Pelomedusa cf. sub - rufa . However, the short linear distance of the south togolese (Badon akapé) speci - mens to P. variabilis from Ghana as well as that both share the same ecoregion speaks in favor of the latter species. MaterIalS anD MetHoDS Study areas and species.- Che - lonian populations from the following local - ities were studied: Badou (atakpamé) for the Kinixys species homeana , erosa (SCHWeIG- Ger , 1812), nogueyi (lataSte , 1886), and Pelomedusa cf. subrufa ; togoville for Pe - lusios castaneus ; and Sokodé for Cyclanor - bis senegalensis (DuMérIl & B IBron , 1835) (Fig. 1). Badou (village of atakpamé) (2 in Fig. 1) is situated in the south-western por - tion of togo, in the ecological zone IV (for - est) situated in the southern section of the togo hills. In the south (ecological Zone IV, kloto area i.e., kuma tomegbe, kpadape, kametonou, Hanyigba), several forest ecosystems are distinguished. there are Celtis and Terminalia superba forest Fig. 1: Map of togo, showing the position of the ecosystems at the mountain flanks and the study areas. eZ I - eZ V - ecozones I-V ( ern 1979). 1 - Sokodé, 2 - Badou, 3 - togoville. Meliaceae and Moraceae forest ecosystems abb. 1: karte von togo mit der lage der unter - with Parinaria excelsa , P. glabra and Poly - suchungsgebiete. eZ I - eZ V - Ökozonen I-V scias fulva in the top regions . at present, (ern 1979). 1 - Sokodé, 2 - Badou, 3 - togoville. the underbrush of these semi-deciduous Segniagbeto_etal_luiselli_population_structure_in_turtles_from_togo_HerpetoZoa.qxd 28.07.2015 14:56 Seite 3 population biology of togolese chelonians 31 P P 1 K s ( ( a M S M t n 7 e e i u D ä g n 8 l forests is often replaced by coffee and cocoa l d ) u o n e i 9 ) i x s m n g a e ) y – farms. the forest islets and the underbrush i c n e d o e s a h b t t d S d s n h e e i a a u are dominated by Piper umbellatum , Dicra - t d n c n f o n a b b s e a n m . l . P a m ( t e s d nolepis grandiflora , Lea guineensis , Roth - M h 1 e t e x c a a a 1 e : l a f r u l ) n : - . n e d mania longiflora , Pteris togoensis , etc. s p e B u M a s s D i u r d u n o e e ( s e i under human pressure (i.e., expansion of e b d s s F s t s v t r c e c ) c e W u i h n a a r farmland due to increasing population size), l f o r w i t t e s a e p i f t i o e i p t a these forests are currently being trans - b b i t r n a n v c h t e . p , h e e e n formed into a continuous grassland savan - e u ( e 1 d s C 1 1 S r t n s . t e u 1 . D a l 1 3 nah-like vegetation type that is easily con - ( r x ( 2 t S S t / 7 9 F ) i V l p s ( t C e ( ) – S a t ( ( l sumed by bush fire. a 0 H i 0 0 t d D l c s . i S W u 0 . ( s p e s 5 0 t ) M e togoville (3 in Fig. 1) is characterized t 5 r e a e 2 8 i o s 0 k c n I i ) ) f ) G n i ) e d by an extended marshy area situated around o e t G n a h s f d e r e e d d r lake togo. the habitats surrounding the K t r r e w a , a i r b v n C 1 1 o t 1 wetlands are mostly degraded and comprise 1 w o i V i 8 . - l o x . 1 . r t 1 0 4 e e x s y a l 4 / 2 i 9 0 i r coastal forest on coastal sand and alluvial C s i e c ‘ h ( l ) ( c S e W g h ( ( . ä 0 h a 0 0 d e u deposits. D l . o r t . 0 . n D n n 0 0 a m ( ) S 6 d g M p i 4 9 the Sokodé area (1 in Fig.