New data on the morphology and natural history of Tetradactylus ellenbergeri (Angel, 1922) (Sauria: Gerrhosauridae) and Trachylepis ivensii (Bocage, 1879) (Sauria: Scincidae) in northeastern Zambia

2012·3.6 MB·English

by  Philipp Wagner

Bonn zoological Bulletin 61 (1): 35-40 July 2012
New data on the morphology and natural history of
Tetradactylus ellenbergeri (Angel, 1922) (Sauria: Gerrhosauridae) and
Trachylepis ivensii (Bocage, 1879) (Sauria: Scincidae)
in northeastern Zambia
Philipp Wagner1.2* Dennis Rodder2 & Thomas M. Wilms3
,
Department ofBiology, Villanova University, Villanova, Pennsylvania 19085, USA.
" Zoologisches ForsclutngsmuseumAlexanderKoenig, Adenauerallee 160, D-53113 Bonn. Germany
Zoologischer Garten Frankfurt, Bernhard-Grzimek-AUee 1, D-60316Frankfurt am Main, Germany
'corresponding author:[email protected].
Abstract. Wereportnewobservationsregardingthemorphology,behaviourandhabitatofthetwosparselyknown lizards
Tetradactylus ellenbergeri (Gerrhosauridae) and Trachylepis ivensii (Scincidae) from northeastern Zambia and review
the available data about the distribution ofboth species.
Key words. Sauria, Trachylepis ivensii, Tetradactylus ellenbergeri, habitat,Africa, Ikelenge, Zambia.
In 2008, a field study was conducted in the Ikelenge area sches ForschungsmuseumAlexander Koenig (ZFMK) in
(northern Mwinilunga District) ofZambia to explore the Bonn, Gennany and the Museum d'histoire naturelle
unique diversity ofamphibians andreptiles in this nation- (MHNG), Geneva, Switzerland.
al biodiversity hotspot. Ikelenge is situated inthe extreme
north-western edge of Zambia within a pedicle wedged
betweenAngola andthe Democratic Republic ofthe Con- Notes on Tetradactylus ellenbergeri (Angel, 1922)
go (DR Congo). Three other studies on the herpetofauna
were conducted in this area in the past. Donald Broadley Tetradactylus ellenbergeri is a snake-like plated lizard
(1991) was the first who summarized a checklist ofrep- from southern central and eastern Africa and the sole
tiles and amphibians ofthe northern Mwinilunga district. member ofthe genus in Zambia. The genus is character-
He recorded 57 reptiles and 35 amphibian species, includ- ized by extremely reduced limbs. In T. ellenbergeri the
ing Tetradactylus ellenbergeri Angel, 1922 for the first front limbs are lacking and the hind limbs are reduced to
time in the area. Later, in 1994, Alan Channing, Robert about 2 mm. The tail is long, more than threetimes longer
Drewes and Jens Vindum also did a field survey which than the body. Individuals are slightly bluish above, with
was mainly concentrated on amphibians. The results of two median vertebral rows ofbrown scales. The tempo-
this studywere neverpublishedbut aspects are mentioned ral region is spotted brownish; the underside is pale olive
in a book on southern African amphibians (Channing (see fig. la).
2001).Also Haagneretal. (2000) collected a series ofboth
amphibians and reptiles from this area, including some Vouchers. ZFMK 88526-529, ZFMK 89188, ZFMK
records ofT. ellenbergeri, andthe discoveryofTrachylepis 89421, ZFMK 92525. Most of the voucher specimens
ivensiiBocage, 1879 forthe firsttime forZambia andthe were found within the Nchila Reserve, Hillwood Farm,
DR Congo. near Ikelenge. One specimen (ZFMK 88529) was found
The herein described field survey was conducted be- bylocal collectors in the surrounding area. Five ofthe sev-
tweenJuly and September2008 to collect amphibians and en preserved specimens are adults and have a snout-vent
reptiles. In this area the rainy season is nearly over in length (SVL) between 59.7 and 68.5 mm, with an aver-
March and therefore this study was done, like the Haag- age of 64.0 mm (n= 5). The single subadult (ZFMK
ner study (W.B. Branch, pers. comm.), in the colder dry 88529) measures 41.4 in SVL. The solejuvenile (ZFMK
mm
seasonjust after the rainy but before the hot dry season. 92525) measures 30.6 and has an original tail with a
During the study time seven specimens of Tetradactylus length (TL) of93.8 mm. In adults, theTLmeasured in av-
ellenbergeriand six specimens ofTrachylepis ivensiiwere erage 186.2 mm (114.2-250.0 mm; n=5) but in fourspec-
collected (see below). The vouchers are stored and cata- imens the tip is cut or the tail is regenerated. The only
logued in the herpetological collections of the Zoologi- specimen (ZFMK 88528) with an original tail measured
Received: 10.10.2011 Corresponding editor: F. Herder
Accepted: 03.04.2012
36 Philipp Wagner et al.
Fig. 1. Tetradactylus ellenbergeri. A= Specimen from Nchila Reserve, Hillwood Farm, Ikelenge, Zambia. B= X-ray image ofa
pregnant female containing two eggs ofT. ellenbergeri. C= Habitat ofT. ellenbergeri in the Nchila Reserve.
Bonn zoological Bulletin 61 (1): 35^0 ©ZFMK
New data ofTetradactylus ellenbergeri and Trachyiepis ivensii in northeastern Zambia 37
20° 30°
Fig. 2. DistributionofTetradactylusellenbergeriand Trachyiepisivensii. T. ellenbergeri. 1=Tanzania: GendawakiValley, Udzung-
wa Mountains (Menegon et al. 2006). 2= Tanzania: Tatanda (Spawls et al. 2002). 3= Tanzania: Songea (Spawls et al. 2002). 4=
DRCongo: Kundelungu(Broadley 1971). 5=DRCongo: Kansenia(Broadley 1971). 6=Zambia: Chongwe River(Broadley 1971).
7=Zambia: Lunga Game Reserve (Broadley 1971). 8= Zambia: Ikelenge area. 9=Angola: Lunda (Broadley 1971). T. ivensii. 10=
DR Congo: Sanolumba Village (Branch & Haagner 1993). 11= Zambia: Ikelenge area, including source ofthe Zambezi and north
ofIkelenge hospital (Branch & Haagner 1993). 12=Angola: Luena (Branch & Haagner 1993). 13=Angola: Dala, Lunda (Branch
& Haagner 1993). 14=Angola: Alto Cuilo (Branch andHaagner 1993). 15=Angola: Alto Chicapa (Branch & Haagner 1993). 16=
Angola: Luando River (Branch & Haagner 1993). 17= Angola: Curanza River (Branch & Haagner 1993). 18= Angola: Cuando
River (Branch & Haagner 1993). 19=Angola: Huambo (Branch & Haagner 1993).
SVL: 60.5 mm and TL: 231.0 mm. This results in a River. Specimens ofT. ellenbergeri were capturedduring
TL/SVL ratio of3.81, and therefore the tail is about four daytime, basking on thetop ofgrass tussocks. Ifdisturbed,
times longerthan the body. Broadley (1991) mentioned a theytriedto escape, diving intothewaterbetweenthe tus-
subadult specimen (National Museums of Zimbabwe, socks. The muddy wateris relatively deep, between 10 and
NMZB 10663) witha SVLof56mmandaTLof200mm, 30 cm. Sphagnum moss (Bryophyta, Sphagnaceae) and
a ratio of3.57. sundew plants (Magnoliophyta, Droseraceae) were found
between the tussocks in this habitat. Both plants indicate
Distribution. InTanzania, the species is only known from apermanentwaterbody. Inthe more open areas ofthe wa-
three localities: Tatanda and Songea are mentioned by ter body, Sphagnum spec, is dense and overgrows the ex-
Spawls et al. (2002), whereas Menegon et al. (2006) found panse ofwater.
the species also at Gendawaki Valley in the Udzungwa
Mountains which is the easternmost record. In Zambia it Naturalhistory. Spawls etal. (2002) mentionedthe species
isknown from three localities (Chongwe River, Lunga Ga- as diurnal and probably oviparous. Haagner et al. (2000)
me Reserve, Ikelenge area), and even in DR Congo and recognized ova and eggs in several specimens collected
Angola it is only known from few localities (see fig. 2). inApril, but one adult female (ZFMK 88526, fieldno. PW
HF 296) collected much later in the year, onAugust 18th,
Habitat. Spawls et al. (2002) noted that the Tanzanian 2008 also containedtwo well developed eggs (see fig. lb).
specimens live in moist savanna. All specimens from the Ifgrasped, these lizards readily shed their tails. How-
Nchila Reserve were found in a similar habitat (fig. lc), ever, tail regeneration is rapid, probably because the tail
a swampy grassland, interspersed with grass tussocks. A is essential for locomotion. A captive specimen regener-
typical suchhabitatis about sixmetres broad and 300 me- ated one centimetre ofa freshly lost tail in four weeks.
tres in length, bordering the gallery forest ofthe Sakeji
Bonn zoological Bulletin 61 (1): 35-40 ©ZFMK
38 Philipp Wagner et al.
Fig. 3. Trachylepis ivensii. A= Specimen from Nchila Reserve, Hillwood Farm, Ikelenge, Zambia. B=Typical habitat ofT. iven-
sii in the Nchila Reserve. C= Typical habitat ofT. ivensii at the Zambezi north ofIkelenge.
Bonn zoological Bulletin 61 (1): 35^10 ©ZFMK
New data ofTetradactylus ellenbergeri and Trachylepis ivensii in northeastern Zambia 59
Notes on Trachylepis ivensii (Bocage, 1879) Habitat. This species was always found near water bod-
ies ormuddy areas, within open grass- orwoodland. Spec-
Trachylepis ivensii is a relatively poorly known scincid imens were observed along the Sakeji and Zambezi Riv-
lizard from south-western centralAfrica and has so faron- er, only a few metres away from the riverbank (see fig.
ly been recorded from a handful ofvouchers worldwide. 3c). Ifthere was gallery forest, individuals were neverob-
Branch & Haagner (1993) reported 21 specimens collect- served on the riverbank, but along the forest border in
ed by them and 17 arepreserved at the Port Elizabeth Mu- muddy grassland(see fig. 3b). However, the species isnot
seum (PEM). Additionally, two specimens were donated just known from watercourses. Voucher specimens in the
to the Lambiris private collection and two to the Natural collection of the California Academy of Sciences (CAS
History Museum ofZimbabwe (NMZB). Nine specimens 196639-641) came from fishponds on Hillwood Farm,
are present in the collection ofthe American Museum of near Ikelenge. Branch & Haagner (1993) found their
National History (AMNH) and three at the California vouchersbasking on logs alongside the origin ofthe Zam-
Academy ofScience (CAS).Also Boulenger(1887) men- bezi River and near Ikelenge hospital at the Zambezi
tionedone specimenpresent in the collection ofthe British rapids. Additionally, they found individuals along the
Museum (BMNH). Together with the six specimens col- Sakeji River at Sakeji School, near Ikelenge.
lected in this study, only 40 vouchers exist in museums
worldwide. The specimens mentioned by Bocage (1879) Natural histoiy. Previous authors recognized the partial-
including the name bearing type are lost (Branch & Haag- ly aquatic habits ofthis species. Laurent (1964) notedthat
ner 1993). local people found the lizard in fish traps, whereas Man-
T. ivensii is a large, elongate species ofthe genus with acas (1963) found the lizards in muddy areas alongside
a greatly enlarged tail (see fig. 3a). It is characterized by riverbanks. Haagneret al. (2000) gave a detailed descrip-
having two to three (usually three) ear lobules and 28-32 tion ofthe behaviour and mentioned specimens basking
scales rows around midbody. Body scales are keeled and onvegetation onthe banks ofthe Sakeji River. Ifdisturbed
heavily keeled over the middle ofthe back. the lizards leapt into thewater, swam underwater with lat-
Belly, throat, underside oftail and limbs are patternless; eral undulations of body and tail and escaped into sub-
limbs are dark brown, with two fine darker lines on the mergedvegetation. We also observedthis behaviour. One
upper sides ofthe forelimbs and a white band separating specimen we tried to catch close to the riverbankjumped
m
the upper and lower surfaces ofthe hindlimbs. Head and offa small cliffinto 1.5 deep water and escaped. Sur-
body are covered with a stripe pattern. On the back and prisingly, three individuals were found in holes that pre-
the tail are three (one vertebral, two dorsolateral) pale sumably were self-excavated by the skinks; one ofthese
brown stripes, arising at the temporal region. Awhite and was dug out by a local man. These burrows were about
dark framed stripe arises on both sides at the nasal region 20 to 30 cm in length and in a distance from river bank
and runs beneath the eye and through the ear along the ofabout one to two meters. However, despite the factthat
A
flanks and fades above the top ofthe hind limbs. sec- T. ivensii only lives near water sources and also swims,
ond such stripe arises beneath the ear and runs along the dives andjumps into the water to escape capture, it is not
lateral part of the body, separating the belly from the an aquatic species, andprobably similarto theAfrican se-
flanks, passing the hind limbs and extending on the tail mi-aquatic species Varanus niloticus (Varanidae) and the
to the tip. The stripes are lacking on regenerated parts of members ofthe scincid genus Cophoscincopus fromWest
the tail. Furthercharacteristics ofthe species are described Africa (Bohme et al. 2000).
by Branch & Haagner (1993) and can be seen in figure Very recently, Blackburn & Flemming (2012) have
3a. shown that reproducing females ovulate tiny eggs and lat-
er supply the nutrients for development by placental
Vouchers. ZFMK 88547-551, MHNG 2713.34. means. Moreover, the recognized pattern of fetal mem-
brane development in T. ivensii is unique among verte-
Distribution. This skinkis onlyknown fromAngola, Zam- brates and the species represents a new extreme in pla-
bia and south-western DR Congo. Branch & Haagner cental specializations ofreptiles (Blackburn & Flemming
(1993) recorded it for the first time in Zambia, from the 2012).
DR
northern Mwinilunga District and the adjacent Con-
go, which are the only known localities from these coun- Acknowledgements.Forassistanceduringthe surveywethank
tries to date. In Zambia the species was only found along the DirectorofResearch Victor Siamudalaand the Head ofRe-
to the Sakeji and Zambezi rivers at Ikelenge area; the DR search Wilbroad Chansa, both from the Zambian Wildlife Au-
Congo record is from Salolumbavillage, 46 kmnorth east thority (ZAWA) and Kennedy Chongoo and Humphrey
Simukoko, both University ofZambia (UNZA, School ofVet-
of Sakeji. In Angola, T. ivensii is known from several erinary Medicine). The Fisher family, Helen Finnie and Esther
rivers in the centre ofthe country (see fig. 2). Townsend fromHillwoodFarm, Zambiahelped alotin collect-
ing lizards and snakes and especially T. ivensii.
Bonn zoological Bulletin 61 (1): 35-40 ©ZFMK
40 Philipp Wagner et al.
Special thanks to Steven Spawls (Norwich), William R. H, MartensK, eds. FreshwaterAnimal DiversityAssessment.
Branch(PortElizabeth) andAndreas Schmitz(Geneva) fortheir Springer, Netherlands, pp. 581-586
critical review ofan earlier draft ofthe manuscript. Bohme W, Schmitz A, Ziegler T (2000) A review ofthe West
The studywaspartly fundedbythe DeutscheGesellschaft fur African skinkgenus Cophoscincopus Mertens(Reptilia: Scin-
Herpetologie&Terrarienkunde(DGHT), theAlexanderKoenig cidae: Lygosominae): Resurrection ofC. simulans (Vaillant,
Stiftung (AKS) andtheAlexanderKoenig Gesellschaft(AKG). 1884) and description ofanew species. Revue Suisse de Zo-
Manythanks forthe fundingwhich gaveusthepossibilityto do ologie 107: 777-791
this research in Zambia. Broadley DG (1991) The herpetofauna ofnorthern Mwinilun-
ga District, northwestern Zambia. Arnoldia Zimbabwe 9:
519-538
ChanningA (2001 Amphibians ofcentral and southernAfrica
)
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Bonn zoological Bulletin 61 (1): 35^40 ©ZFMK