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56 Accepted by M. Vences: 24 Dec. 2009; published: 10 Feb. 2010
ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Copyright © 2010 · Magnolia Press
Zootaxa 2355: 56–68 (2010)
www.mapress.com/zootaxa/Article
Rediscovery of the Liberian Nimba toad, Nimbaphrynoides liberiensis (Xavier,
1978) (Amphibia: Anura: Bufonidae), and reassessment of its taxonomic status
LAURA SANDBERGER1, ANNIKA HILLERS1, JOSEPH DOUMBIA2, NÉMA-SOUA LOUA3,
CHRISTIAN BREDE4 & MARK-OLIVER RÖDEL1,5
1Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity at the Humboldt University Berlin,
Herpetology, Invalidenstr. 43, 10115 Berlin, Germany. E-mails: laura.sandberger@mfn-berlin.de; annika.hillers@mfn-berlin.de;
mo.roedel@mfn-berlin.de
2Centre d'Étude et de Recherche en Environnement (CÉRE), Université de Conakry, BP 3817, Conakry, Guinée.
E-mail: joevero76@yahoo.fr
3Société des Mines de Fer de Guinée, Cité Chemin de Fer, Immeuble Faranah, BP 2046, Kaloum, Conakry, Republic of Guinea.
E-mail: nsloua@yahoo.fr
4Medizinische Klinik und Poliklinik II, Zentrum für Experimentelle Molekulare Medizin, Zinklesweg 10, 97078 Würzburg, Germany.
E-mail: brede_c@medizin.uni-wuerzburg.de
5Corresponding author. E-mail: mo.roedel@mfn-berlin.de
Abstract
We report on the search and rediscovery of the Liberian Nimba toad, Nimbaphrynoides liberiensis, 30 years after its
original description. A small surviving population could be traced in the surroundings of the type locality Mount Alpha,
Liberia. The type locality was meanwhile destroyed by open cast mining. Similar to the Guinean Nimba toad,
Nimbaphrynoides occidentalis, the Liberian toad lives exclusively in open, savanna like habitats above 1200 m a.s.l. The
presumably few surviving individuals and the small and patchy distribution classify the Liberian toads as Critically
Endangered (Stuart et al. 2008). A morphological, acoustical and genetic comparison of Liberian and Guinean
populations revealed only minor, but distinct morphological (size, colour) differences. Genetically and acoustically the
two taxa were indistinguishable. We therefore propose to consider the two populations as conspecific and to consider
Nimbaphrynoides liberiensis (Xavier, 1978) as junior synonym of Nimbaphrynoides occidentalis (Angel, 1943). Because
of the morphological differences we propose to treat the Liberian population as a subspecies of the Guinean toad and
herein introduce the new name: Nimbaphrynoides occidentalis liberiensis.
Key words: Conservation status, Guinea, Liberia, mining, montane grassland, Nimbaphrynoides occidentalis,
Nimbaphrynoides occidentalis liberiensis, taxonomy
Introduction
In 1943 F. Angel described a new toad species from Mount Nimba as Nectophrynoides occidentalis. He first
believed that this toad was ovo-viviparous, but soon new data on the spectacular, truly viviparous
reproductive biology of this unique toad became known (e.g. Angel & Lamotte 1944, 1948; current
knowledge summarized by Xavier 1986). This toad was exclusively recorded from a few km² of montane
grasslands on the Guinean part of Mount Nimba (Lamotte 1959; Lamotte & Sanchez-Lamotte 1999; Hillers et
al. 2008; very recently we detected one site on the Ivorian part of the mountain, L. Sandberger et al. unpubl.
data). The Nimba mountain range includes parts being positioned in nowadays Guinea, Ivory Coast and
Liberia (Lamotte 1998; Lamotte & Roy 2003). Due to rich deposits of iron ore the mountains were in the
focus of mining prospecting activities since the 1950s (Lamotte 1983).
In the course of iron ore prospecting in the Liberian part of the Nimba range M. Coe detected Nimba toads
on Liberia’s highest mountain, the Mount Alpha in 1964. These toads were subsequently described by F.
Xavier as a new likewise viviparous species, Nectophrynoides liberiensis (Xavier 1978; Fig. 1). This
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description was mainly based on morphological differences to N. occidentalis, i.e. N. liberiensis females may
be as large as 35 mm, N. occidentalis females rarely surpass 24 mm (however: N. occidentalis holotype: 27.5
mm). Additional arguments for the species description were small colour differences (i.e. the presence of
brown dots on the belly of most of the Liberian toads) and hybridization experiments (Xavier 1978).
More recently, both Nimba toads were placed in an own genus, Nimbaphrynoides by Dubois (1987) and
classified as being Critically Endangered (Stuart et al. 2008). However, newer data on the two toads are rare
(N. occidentalis: Lamotte & Sanchez-Lamotte 1999; Hillers et al. 2008) or completely missing (N.
liberiensis). The type locality of N. liberiensis meanwhile was explored for iron ore (1960 to early 1990) and
what formerly was Mount Alpha, now is an open cast mining pit (Fig. 2). We aimed to verify if the Liberia
Nimba toad still exists and if so, to reassess its taxonomic status.
Material and methods
In order to search for Liberian Nimba toads we visited the area of the former Mount Alpha and its
surroundings near Yekepa three times in 2007 (28 June, 22 July, 23–25 August) and once in 2008 (25–27
May). We investigated heavily impacted areas (e.g. old mining pit), less impacted areas (further away from
the main mining site and old mining roads), open as well as forested areas, by carefully checking the
vegetation and potential hiding places, between app. 900 m a.s.l up to the remaining mountain tops (1375 m
a.s.l.). Searches were undertaken between 9:30 am and 4:30 pm. We employed visual encounter searches
along transects (e.g. Rödel & Ernst 2004; N = 15) and standardized plot searches (N = 4) as described by
Hillers et al. (2008). We thus investigated all potential and accessible habitats of the Liberian Nimba toad in
this region. Geographic positions of study sites were recorded with a GPS receiver (Garmin 72). In total we
searched for app. 63 man-hours. All investigated localities are shown in Fig. 3 and summarized in the
appendix.
Toe-tips were taken for genetic comparisons and stored in 96% ethanol. Additionally, we collected a few
vouchers. These were anesthetised in a chlorobutanole solution and subsequently preserved in 75% ethanol.
Tissue samples and vouchers are kept in the herpetological collection of the Museum für Naturkunde, Berlin
(N. liberiensis: ZMB 73871-73877; five females, one male, one juvenile). The type series of N. liberiensis
was investigated in the collection of the Muséum National d’Histoire Naturelle, Paris (holotype: MNHN
1978.3088; paratypes: 1978.3089–3103; 1978.3111–3114; 1978.3116–3126; 16 females, 14 males; juveniles
of the type series not investigated). These toads were compared to the N. occidentalis type series (holotype:
MNHN 1944.149; para- and paratopotypes: 1944.151–152, 1944.154–159; nine females; three juveniles not
investigated), N. occidentalis specimens stored in Berlin (ZMB 70660, 73878-73890; 12 females; six males)
and to snout-vent length (SVL) measures taken in 2007 and 2008 in the field (N. occidentalis: N = 603,
females: 469, males: 134; N. liberiensis N = 68, females: 44, males: 24). For the morphological comparison
we measured SVL, head width (HW), femur length (FL), tibia length (TB) and food length incl. longest toe
(FoL). With the exception of SVL, measures have been taken from museum vouchers only. All measures were
taken with a dial calliper (± 0.1 mm) and are given in millimetres. For statistical comparison we carried out t-
tests (all data showed a normal distribution and homogeneity in variance). All calculations were carried out
with the freeware software package R.
In 2007 we succeeded in recording advertisement calls of one N. liberiensis male. In 2008 we recorded the
calls of 11 N. occidentalis males. Calls were recorded with a R-09 24bit WAVE/ MP3 recorder (ERIDOL by
Roland, sample rate: 44.1 kHz, record mode: wav_24bit) and a microphone (ECM-950). These calls were
analysed with the programme Avisoft SAS Lab Pro 4.5 (R. Specht, Berlin, Germany).
DNA was extracted using High Pure PCR Template Preparation kits (Roche) following manufacturer’s
instructions. We used primers 12SA and 12SB to amplify part of the 12S gene and 16SA and 16SB for the
partial 16S rRNa gene; all primers are from Palumbi (1991). The cytochrome b (cyt b) gene was amplified
with the primers CBJ10933 and Cytb-C from Bossuyt & Milinkovitch (2000). Standard PCR protocols were
used and PCR products were purified using High Pure PCR Product Purification kits (Roche). Purified
SANDBERGER ET AL.58 · Zootaxa 2355 © 2010 Magnolia Press
templates were directly sequenced using an automated sequencer (ABI 3100). In total, we sequenced 16 tissue
samples (nine N. liberiensis, seven N. occidentalis) for 12S (390bp), 12 (five N. liberiensis, seven N.
occidentalis) for 16S (552 bp) and 10 specimens (four N. liberiensis, six N. occidentalis) for cyt b (608 bp; see
Table 3). Sequences were validated using SEQUENCE NAVIGATOR (Applied Biosystems). We aligned
them using the Clustal W option in MEGA 4.1 (Tamura et al. 2007). The alignment was subsequently checked
by eye and refined if necessary. Uncorrected pair-wise sequence divergence was calculated using PAUP*
4beta10 (Swofford 2002).
FIGURE 1. Dorsal and ventral view of (left) the holotype of Nimbaphrynoides liberiensis (MNHN 1978.3088; SVL
29.2 mm) and (right) the holotype of Nimbaphrynoides occidentalis (MNHN 1944.149; SVL 27.5 mm).
Results
We rediscovered the Liberian Nimba toad, both north and south of the old LAMCO (Liberian-American-
Swedish Minerals Company) mining pit. In total we detected 30 toads (14 adults: five females, six males,
three subadults, 16 juveniles) in 2007. In 2008 we encountered a total of 22 toads, 17 females (16 being
pregnant), and five males.
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Most individuals were found south of former Mount Alpha and each year only one female was found
north of it. At several localities we could not find any toads (Fig. 3). We observed toads only within the less
impacted parts, where mining was abandoned after 10 years. They were absent from strongly impacted
localities, i.e. where mining took place for more than 30 years. All places with toads had soil that was not or
little compacted, i.e. holes and cracks were visible. At sites without such structures no toads could be traced.
All toads were recorded in open areas at 1200 m a.s.l. and above.
FIGURE 2. Type locality of Nimbaphrynoides liberiensis (the meanwhile destroyed Mount Alpha, above) and a
degraded habitat south of the mining pit, currently used by the Liberian Nimba toad.
SANDBERGER ET AL.60 · Zootaxa 2355 © 2010 Magnolia Press
FIGURE 3. Sites investigated for Nimba toads and current distribution of Nimbaphrynoides liberiensis. Black dots
(plots) and triangles (transects) indicate where we encountered Liberian Nimba toads. At white dots (plots) and triangles
(transects) we failed to record them. The black box and the arrow indicate the water filled mining pit of the LAMCO
mine, the former Mount Alpha (compare Fig. 2). Note erosion left and right of the mining pit. The area indicated by the
dotted line was less intensively minded (10 years only) than Mount Alpha (1960 to early 1990). The grey line north of
the mining pit indicates a further area investigated (nine man-hours) for Nimba toads without success (map adopted from
Spot_Image Jannuary 2005).
For the SVL comparison we used museum vouchers and measurements taken in the field. Females were
significantly larger than males in both taxa (N. occidentalis females: mean length 20.5 mm, N = 490; males:
18.0 mm, N = 149, p< 0.05; N. liberiensis females: 28.7 mm, N = 65; males: 22.4 mm, N = 39, p< 0.001; Fig.
4). N. liberiensis were significantly larger than N. occidentalis (males: p< 0.001; females: p< 0.001),
respectively. Even after being corrected for size (FoL/SVL) N. liberiensis females (N = 19) and males (N =
13) had significantly longer feet than N. occidentalis (females N = 12, males N = 6; p< 0.05). Other
morphological parameters did not differ between taxa (Table 1). To account for the possibility of geographic
clinal variation we correlated all SVL field measures from 2007 and 2008 (Nfemales = 483, Nmales = 143) with
latitude. Analyses were done with respect to sex, but irrespective of the taxa. We found no geographic
correlation.
The colouration of adults in both taxa was variable (Figs. 1, 5 & 6). Most individuals had white venters
and brown to black backs without a distinct border between the two colours. The back may be uniform in
colouration or lighter and darker browns may be irregularly mixed. Heads had always, at least on the snout
and the eye-lids, lighter areas. The legs were always light brown with irregularly bordered darker stripes or
dots. Juveniles had brighter coloured backs than adults. Juveniles of both taxa had a black, white bordered,
lateral line, starting at the snout-tip, passing through the eyes and extending to the groin area. Their back had
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a golden-brownish ground colour and may carry irregular or symmetrical shaped blackish spots and figures.
Their legs were yellow to brown with white stripes. With age and increasing size their backs and legs became
darker, the contrast between differently coloured areas fainted. In comparison N. liberiensis females seemed
to comprise the most uniform, N. occidentalis, the most contrasting individuals. None of the several hundred
investigated N. occidentalis was found to have brown dots on the belly or throat. In contrast, some living N.
liberiensis had small to large light brown dots on their venter (Fig. 5). These dots seemed to be generally more
conspicuous in alcohol preserved material. In some of the latter specimens the venter was nearly completely
brown.
TABLE 1. Mean values of morphological measures of Nimbaphrynoides occidentalis and N. liberiensis (only museum
vouchers included) and t-test results between the two taxa. The sexes were compared separately. All measures had been
standardized against snout-vent length prior to comparisons. Only feet (FoL) of N. liberiensis were significantly larger
than those of N. occidentalis. For abbreviations compare Material & Methods; N = sample size; n.s. = not significant.
Both species start uttering advertisement calls at approximately the middle of the rainy season, i.e. July.
Main calling activity is however later at the beginning or middle of September. The advertisement call was
very faint, short and resembled a metallic “bing” (Fig. 7). We got recordings of this call of one N. liberiensis
male and eleven N. occidentalis males, thus allowing for descriptive analyses only. The advertisement call had
two distinct parts: it started with a slightly higher frequency and more energy and ended with lower energy
and slightly lower frequency. The longer end part was more variable than the first one. The frequencies of the
calls (total call and each part separately) of N. liberiensis (mean[total call] = 3568 Hz; mean[first part of call]
= 3565 Hz; mean[rest of call] = 3477 Hz) were slightly higher than the frequencies of N. occidentalis
(mean[total call] = 3141 Hz; mean[first part of call] = 3319 Hz; mean[rest of call] = 2775 Hz). The other call
parameters (number of pulses, lengths of the call and call parts, proportion of the energy of the second to the
first part) did not differ notably (Table 2). In N. occidentalis we recorded a second, relatively uniform
“rasping” call, mostly heard during aggressive encounters between males as well as during mating. When
uttered during antagonistic encounters this call seemed to chase an intruder away, without physical combat.
This call was considerable longer than the advertisement call (0.126 sec compared to 0.018 sec). The mean
frequency (3177 kHz) was similar to the advertisement call (Fig. 7). This call may start or, more often, end
with the advertisement call. Schiøtz (1964) reported a third call type for N. occidentalis, a slow chirp with a
sex variable species mean Nt-value df p
females HW occidentalis 0.32 12 -1.8169 16.907 n.s.
liberiensis 0.30 21
males occidentalis 0.32 6-0.8399 5.775 n.s.
liberiensis 0.30 15
females FL occidentalis 0.44 12 1.4185 25.586 n.s.
liberiensis 0.47 21
males occidentalis 0.45 61.3183 5.388 n.s.
liberiensis 0.48 15
females TL occidentalis 0.42 12 1.2579 23.932 n.s.
liberiensis 0.44 21
males occidentalis 0.44 61.5919 5.291 n.s.
liberiensis 0.48 15
females FoL occidentalis 0.65 12 3.7655 16.996 <0.05
liberiensis 0.73 19
males occidentalis 0.64 63.4065 5.789 <0.05
liberiensis 0.73 13
SANDBERGER ET AL.62 · Zootaxa 2355 © 2010 Magnolia Press
wave-like frequency modulation. He believed that this call type could be an initial call. We so far never heard
such a call.
We detected minor genetic differences between the two taxa. They were largest between the two taxa and
lowest within N. liberiensis (Table 3). However, even the largest difference between the two taxa, found in cyt
b, was only about 2%.
TABLE 2. Comparison of advertisement call (A in Fig. 7) parameters of one Nimbaphrynoides liberiensis and eleven N.
occidentalis males. The call consists of two parts, a first part (first) which is louder and higher than the second part (rest).
The latter is the more variable part of the call. For all parameters the mean and range (in parentheses) is given for the
total call, the first part and the second part of the call (rest). Length of a call and length between calls is given in seconds
[s]; main frequency given in hertz [Hz]. The energy of the first part of the call (Energyfirst) is given as relative value to the
energy of the rest of the call (Energyrest) as Energyfirst/ Energyrest.
FIGURE 4. Sex dependant snout-vent-lengths comparisons of Nimbaphrynoides occidentalis (black) and N. liberiensis
(white). N. liberiensis were significantly larger than N. occidentalis (see text).
species occidentalis liberiensis
# pulses 4.9 (3–7) 6.6 (3–13)
length [s] total call 0.018 (0.012–0.026) 0.020 (0.009–0.041)
first 0.004 (0.003–0.005) 0.005 (0.003–0.011)
rest 0.007 (0.015–0.022) 0.045 (0.005–0.255)
time to next 107.012 (48.000–471.000) 104.220 (21.960–252.000)
frequency [Hz] total call 3141 (2020–4560) 3567 (2390–5570)
first 3319 (2190–4560) 3565 (2430–5570)
rest 2775 (2020–4000) 3477 (2390–4500)
Energyfirst/ Energyrest 4.021 (0.555–11.730) 5.386 (0.324–22.220)
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TABLE 3. Genetic distances (uncorrected p-distance) in percent between Nimbaphrynoides occidentalis and N.
liberiensis and within each taxon, for 12S, 16S and cytb sequences. Given are mean, minimum (min) and maximum
(max) values. Below we listed all voucher and tissue samples with their corresponding GenBank accession numbers;
n.v.= no voucher collected.
Discussion
The description of N. liberiensis was mainly based on small morphological (size) and colour (dots on belly
and throat) differences to N. occidentalis (Angel 1943; Xavier 1978). These differences could be confirmed
herein. Additionally, F. Xavier undertook hybridization experiments between the two taxa in her Paris
laboratory. She found that none of the offspring survived when fathered by a Liberian and mothered by a
Guinean toad (of 15 pairings only one female gave birth, however to dead young). In contrast, 80% of the
offspring fathered and mothered by N. liberiensis were borne alive (Xavier 1978). However, F. Xavier
apparently did not try to breed a N. occidentalis female with a N. liberiensis male. The failure of getting
offspring could be due to the fact that the sizes did not fit. This species has to have internal fertilization and
size relation between sexes may thus be an important feature to assure successful fertilization. However, we
don’t believe that this is a very convincing argument (compare Fig. 5). In fact we found only very minor
genetic differences in mitochondrial gene sequences, in loci usually used for DNA-barcoding in amphibians
(compare Vieites et al. 2009). As also another important character for species delimitation in anurans, the
advertisement call, did not differ, hybridization between the two taxa seems potentially possible.
Xavier (1978) gave habitat descriptions for three localities. They were described as being open, having
steep slopes, loose stones or crevices and positioned near mining roads (presumably recorded here because of
easier access). We could find the Liberian toad exclusively in open areas (Fig. 2), and as already stated by
Xavier (1978), only above 1200 m a.s.l. and at sites with holes and cracks in the ground. The original sites
Sequence comparison 12S 16S cyt b
mean min max mean min max mean min max
Between taxa 0.002 00.005 0.002 00.004 0.020 0.016 0.023
Within liberiensis 0.001 00.005 0 0 0 0 0 0
Within occidentalis 0.001 00.003 0.002 00.005 0.007 00.013
Taxon Vou che r # Tissue # GB16S GB12S GBCytb
liberiensis ZMB 73875 MOG012 GU322838 GU322821 GU322850
ZMB 73876 MOG013 GU322839 GU322822 GU322851
n.v. MTN245 GU322840 GU322823 GU322858
n.v. MTN246 GU322841 GU322824 GU322859
n.v. MTN247 GU322842 GU322825
n.v. MTN248 GU322826
n.v. 07_204_Lib GU322828
n.v. 07_205_Lib GU322829
n.v. 07_215_Lib GU322830
occidentalis ZMB 73881 MOG018 GU322843 GU322831 GU322852
ZMB 73882 MOG019 GU322844 GU322832 GU322853
ZMB 73886 MTN83 GU322849 GB322837 GU322857
n.v. MTN15 GU322845 GU322833 GU322854
n.v. MTN16 GU322846 GU322834 GU322855
n.v. MTN22 GU322847 GU322835
n.v. MTN78 GU322848 GU322836 GU322856
SANDBERGER ET AL.64 · Zootaxa 2355 © 2010 Magnolia Press
FIGURE 5. Life coloration of Nimbaphrynoides liberiensis; above: comparison of Nimbaphrynoides females, N.
occidentalis (left) and N. liberiensis (right; ZMB 73875); centre: amplectant couple of N. liberiensis (female: ZMB
73873; male: ZMB 73874) and juvenile N. liberiensis (inlet left, ZMB 73877); below: two N. liberiensis with darker
spots on throat and belly.
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FIGURE 6. Female (above), male (below) and juvenile (inlet) of Nimbaphrynoides occidentalis.
SANDBERGER ET AL.66 · Zootaxa 2355 © 2010 Magnolia Press
FIGURE 7. Oscillogram and waveform of the advertisement calls (A) of Nimbaphrynoides liberiensis and N.
occidentalis and a presumed aggressive call of N. occidentalis (B, compare text).
were given as: mining plateau, Mount Alpha and mining road. Now the mining plateau and Mount Alpha are
mostly reduced to altitudes below 1200 m a.s.l. (Fig. 2) and we failed to record any toads at these sites.
Although many areas seem to equal the ones described by Xavier (1978), we only recorded the Liberian toad
at some localities and always in comparatively low densities (see Lamotte 1959; Hillers et al. 2008). Most
area above 1200 m a.s.l. is heavily altered, either offering only very compacted soil without hiding places or
consisting of loose gravel. It is very likely that the toads need good, i.e. deep and solid hiding places,
especially in order to survive the long dry season (compare Lamotte 1959). The main population now seems
to be restricted to areas south of the old mining pit. North of it we only detected two females. It seems unlikely
that the toads may migrate between these two sites as 1) the habitat in-between is extremely degraded and 2)
lays below 1200 m a.s.l. It is a good sign that these toads were capable to survive this extreme habitat
alteration. However, due to the very small and isolated habitat patches, combined with presumably very small
population sizes, the Liberian Nimba toad must be still considered Critically Endangered. Its remaining
habitats should be carefully monitored and maintained.
Remains the question whether the two Nimba toad taxa should be considered representing different
species or not. The genetic differences between Guinean and Liberian populations are minute and far below
what usually are taken to differentiate between anuran species (Rödel et al. 2003, 2009; Vences et al. 2005). In
contrast, the morphological differences (size and ventral pattern) are sufficient to correctly assign at least most
specimens to one or the other name. Furthermore, we are aware of the possibility that the observed genetic
similarity could originate from mitochondrial introgression which is not uncommon in amphibians, as has
been shown e.g. in newts (Babik et al. 2003) or the frog genera Meristogenys and Ameerega (Shimada et al.
2008; Brown & Twomey 2009). In these species nuclear genes revealed the existence of distinct differences
on the species level. Unfortunately we failed to amplify nuclear genes of the Nimba toads. Both toad taxa,
living exclusively in open, savanna like montane habitats, are separated by a distance of about 7.5 km,
comprising a forested mountain ridge. Although it is thus unlikely that both toad taxa are in frequent genetic
exchange; the observed genetic, acoustic and morphological differences altogether are too small to justify the
maintenance of two different species names. However, to account for the existence of the small genetic and
morphological differences, we propose to maintain a separate name for the Liberian population, although in
the rank of a subspecies: Nimbaphrynoides occidentalis liberiensis.
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Acknowledgements
We thank the “Forestry Development Authority”, namely J. Woods and T. Freeman in Liberia to allow
research on the Liberian part of the Nimba range. The Guinean authorities, particularly the “Ministère de
l’Agriculture, de l’Elevage, de l’Environnement et des Eaux et Fôrets”, represented by C.S. Kourouma,
permitted work on the Guinean part of Mount Nimba. The “Centre de Gestion de l’Environnement du Nimba-
Simandou”, the “Projet des Nations Unies de Développement” and the three “Comités Villageois de
Surveillance” allowed us to work within the World Heritage Site. The research permit in Guinea was issued
by the “Ministere de l'Education Nationale et de la Recherche Scientifique/ Direction Nationale de la
Recherche Scientifique et Technologique ” (No. 095; MNRS/DNRST). The ”Ministère du Developement
Durable et de l'Environement/ Direction Nationale des forets et faune” permitted the capture and collection of
the Guinean Nimba Toad (permis sceintifique de capture, No. 02/2008). We thank Arcelor-Mittal and
especially M. Majumdar, for accommodation, food and the permission to search at the old LAMCO mine in
Liberia. We are grateful to the “Société des Mines de Fer de Guinée” and its stuff for the financial support, and
for all the other help and support, especially to J. Suter and C. Halpin. A. Ohler and A. Dubois facilitated the
examination of the type material in the Paris collection. S. Soubzmaigne took the picture of the N. liberiensis
holotype. We especially thank the “Bundesamt für Naturschutz”, Bonn for issuing CITES import permits
(Nimbaphrynoides occidentalis; E-3117/07 and E-4074/08; Nimbaphrynoides liberiensis; E-4509/07). The
respective export permits were issued by “Le Directeur Nationale de la Protection de la Nature”(2007/ 00314)
and “L’organe de Gestion CITES Guinée” (2008/ 0049) in Guinea (Nimbaphrynoides occidentalis) and by the
“Forestry Development Authority” in Liberia (01, Nimbaphrynoides liberiensis). Last but not least we are
much indebted to our field assistants B. Doré, K. Camara and F. Gbêmou for their excellent work and good
humour.
References
Angel, F. (1943) Description d’un nouvel amphibien anoure, ovo-vivipare de la Haute-Guinée Française (Materiaux de la
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Appendix. Study sites searched for Nimbaphrynoides liberiensis. Given are the area ID, the location (south or north of
the LAMCO mine, former mount Alpha, compare Fig. 3), latitude, longitude, altitude, search date, the number of
encountered adults (n° ad), juveniles (n° juv) and total number of toads (n° an). P1–P4 represent standardized plot
searches (25 m² see Hillers et al. 2008 for exact description), R01–R15 represent random transects.
Area location latitude longitude altitude date n° ad n° juv n° an
P1 South 7.53468 -8.50143 1293 23/08/2007 2 0 2
P2 South 7.52675 -8.51113 1295 24/08/2007 0 1 1
P3 South 7.52168 -8.51470 1323 24/08/2007 0 0 0
P4 South 7.51698 -8.52158 1329 24/08/2007 0 0 0
R01 North 7.52168 -8.52937 1267 27/07/2007 0 1 1
R02 North 7.52723 -8.50968 1318 27/07/2007 210 12
R03 South 7.51698 -8.52158 1246 23/08/2007 4 4 8
R04 South 7.51698 -8.52158 1288 23/08/2007 5 0 5
R05 South 7.51928 -8.51819 1375 24/08/2007 0 0 0
R06 South 7.54545 -8.48682 1240 25/08/2007 0 0 0
R07 South 7.54936 -8.48716 1190 25/08/2007 0 0 0
R08 South 7.54639 -8.48284 1186 25/08/2007 1 0 1
R09 South 7.53442 -8.50091 1249 25/05/2008 0 0 0
R10 South 7.53408 -8.50194 1281 25/05/2008 16 016
R11 North 7.54944 -8.47970 1302 26/05/2008 0 0 0
R12 North 7.54785 -8.48130 1234 26/05/2008 1 0 1
R13 North 7.54731 -8.48258 1180 26/05/2008 0 0 0
R14 South 7.52808 -8.50989 1313 27/05/2008 5 0 5
R15 South 7.51685 -8.52131 1324 27/05/2008 0 0 0