Research Article |
Corresponding author: Raffael Ernst ( raffael.ernst@senckenberg.de ) Academic editor: Johannes Penner
© 2020 Raffael Ernst, Thea Lautenschläger, Makaya Futuro Branquima, Monique Hölting.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Ernst R, Lautenschläger T, Branquima MF, Hölting M (2020) At the edge of extinction: a first herpetological assessment of the proposed Serra do Pingano Rainforest National Park in Uíge Province, northern Angola. Zoosystematics and Evolution 96(1): 237-262. https://doi.org/10.3897/zse.96.51997
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We systematically assess the herpetofaunal diversity of the Serra do Pingano Forest Ecosystem (SPFE) and additional localities throughout the northern Angolan province of Uíge during four independent Rapid Assessment (RA) field campaigns held between 2013 and 2019. These assessments represent the first systematic surveys of amphibians and reptiles from the province, and thus we provide the first province-wide species list. We collected data on the status and current threats to amphibians and reptiles in the proposed Serra do Pingano Rainforest National Park and were able to document 33 species of reptiles from Uíge province. Of the 33 species recorded from the province, 10 species are exclusively found in the SPFE. Amphibian surveys yielded 47 amphibian species from the province. These include 14 new country records and additional records that may represent undescribed species. This raises the amphibian count for Angola to at least 133 species, which includes 18 species exclusively found within the SPFE. Species-richness estimators indicate that more species should be detected if survey efforts are intensified. The species composition in the SPFE is unique and consists of a high proportion of forest specialists with restricted ranges and species found nowhere else in the country. This emphasizes today’s paramount importance of the SPFE, which is threatened by increasing agricultural encroachment and uncontrolled timber extraction and charcoal production. These principal factors need to be controlled and/or abandoned in already impacted areas. Conservation strategies should particularly consider the strict protection of remaining intact forests and both lentic and lotic aquatic systems. They are not only crucial for safeguarding a significant number of species that depend on these habitats for reproduction; they also provide key ecosystem services to the local population. Angola, and Uíge province in particular, is at a crossroads concerning decisions and trade-offs among utilization, conservation, and preservation of its forests and, thus, substantial parts of the country’s biodiversity. The establishment of a National Protected Area in the Serra do Pingano Ecosystem is therefore a necessary and urgently needed first step towards protecting Angola’s national biodiversity heritage.
Amphibia, biodiversity survey, conservation, new country records, rainforest fragments, Reptilia
Northern Angola, including the provinces of Cabinda, Lunda Norte, Uíge, and to a lesser extent Malanje and Cuanza Norte, harbours the last remaining tracts of already heavily fragmented rainforest. These forest ecosystems have been largely neglected in biodiversity surveys. However, due to an assumed link with the large Congolese Forest Bioregion and their unique position within the range of Angolan ecosystems, they promise to harbour an exceptionally rich flora and fauna. Today, sizable and important patches can only be found in Cabinda and Uíge. The latter province is particularly known for the Serra do Pingano Forest Ecosystem (SPFE), a site of recent herpetological explorations (
Amphibians and reptiles are amongst the world’s most threatened organisms (
Amphibians, due to their peculiar biology and diversity of reproductive strategies (
Today’s knowledge of Angola’s national biodiversity remains poor compared to that of other Sub-Saharan countries. This is particularly true for herpetofaunal diversity. Although herpetological research in Angola dates back to the late 19th century (e.g.
Herpetofaunal diversity of the Serra do Pingano Forest Ecosystem (SPFE) was systematically assessed during four independent Rapid Assessment (RA) field campaigns (1st campaign: 2–16 October 2013; 2nd campaign: 30 October–17 November 2014; 3rd campaign: 15 September–3 October 2018; 4th campaign: 11–22 November 2019) and opportunistically between 2013 and 2019. Sampling was conducted at three core localities forming the larger Serra do Pingano Forest Ecosystem (from north to south: 1. Serra do Uíge (SU; core location: 7.6173S, 15.0658E), 2. Serra do Pingano (SP; core location: 7.6845S, 14.9298E), and 3. Serra Vamba (SV; core location: 7.8412S, 14.8422E), Fig.
Study area depicting the larger Serra do Pingano Forest Ecosystem (SPFE) with core herpetological survey sites (white rectangle) and sampling localities (blue dots, 50 independent localities). From north to south: SU: Serra do Uíge, SP: Serra do Pingano, SV: Serra Vamba. The inlet left provides a coarse overview on major vegetation formations in Uíge province according to
We used opportunistic visual and acoustic encounter surveys (VES and AES) both during the day and at night, supplemented by arrays of pitfall traps placed along drift fences in combination with funnel traps (
While we were able to obtain a very solid overview of the amphibian fauna of the region, reptiles are largely underrepresented in our sampling and reptile data must be considered too incomplete to allow comprehensive conclusions. Nonetheless, we recorded several unique species and species of conservation concern in both taxonomic groups.
Of the more than 280 species of reptiles reported for Angola today, we were able to record 33 species from Uíge province. Although this is a significant increase compared to the previously reported seven species (
Reptile species recorded in the Serra do Pingano Forest Ecosystem (SPFE) and the wider province of Uíge (in alphabetic order) with occurrence in respective core areas (SU: Serra do Uíge, SP: Serra do Pingano, SV: Serra Vamba, UP: Uíge province outside SPFE), general range (ANG: Angola including Cabinda, WCA: West-Central Africa, SSA: Sub-Saharan Africa (any range beyond WCA)) and general habitat type (PF: primary forest, DF: degraded forest, OH: open habitats, including natural savannahs as well as anthropogenic habitats and peri-urban sites). * = species listed under CITES II. ? = status questionable/not yet confirmed.
Taxa | Restricted to | Habitat | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
SU | SP | SV | UP | ANG | WCA | SSA | PF | DF | OH | |
Reptilia | ||||||||||
Testudines | ||||||||||
Pelomedusidae | ||||||||||
Pelusios rhodesianus | x | x | x | x | ||||||
Testudinidae | ||||||||||
Kinixys belliana* | ? | ? | ? | x | x | ? | ? | ? | ||
Crocodylia | ||||||||||
Crocodylidae | ||||||||||
Crocodylus niloticus | ? | ? | ? | X? | x | x | x | |||
Sauria | ||||||||||
Agamidae | ||||||||||
Agama agama-complex | x | x | x | x | ||||||
Chamaeleonidae | x | x | ||||||||
Chamaeleo gracilis etiennei | x | x | x | x into DRC | x | x | ||||
Gekkonidae | ||||||||||
Hemidactylus paivae | x | x | x | x | x | |||||
Hemidactylus longicephalus | x | x | x | |||||||
Gerrhosauridae | ||||||||||
Gerrhosaurus cf. nigrolineatus | x | x | x | x | x | |||||
Lacertidae | ||||||||||
Holaspis guentheri | x | x | x | |||||||
Scincidae | ||||||||||
Panaspis cabindae | x | x into DRC | x | |||||||
Trachylepis cf. affinis | x | x | x | x | x | x | x | |||
Trachylepis maculilabris | x | x | x | |||||||
Varanidae | ||||||||||
Varanus niloticus * | x | x | x | x | ||||||
Serpentes | ||||||||||
Colubridae | ||||||||||
Crotaphopeltis hotamboeia | x | x | x | x | ||||||
Dispholidus typus punctatus | x | x into DRC | x | x | ||||||
Grayia ornata | x | x | x | x | ||||||
Philothamnus carinatus | x | x | x | x | ||||||
Philothamnus dorsalis | x | x | x | x | ||||||
Thelotornis kirtlandii | x | x | x | x | ||||||
Thrasops jacksonii | x | x | x | x | ||||||
Toxicodryas blandingii | x | x | x | x | ||||||
Elapidae | ||||||||||
Dendroaspis jamesoni | x | x | x | x | x | |||||
Elapsoidea semiannulata | x | x | x into Zambia & Namibia | x | x | |||||
Naja melanoleuca | x | x | x | x | ||||||
Lamprophiidae | ||||||||||
Boaedon angolensis | x | x | x | x | ||||||
Boaedon olivaceus | x | x | x | |||||||
Lycophidion cf. multimaculatum | x | x | x | |||||||
Natricidae | ||||||||||
Natriciteres olivacea | x | x | x | |||||||
Pythonidae | ||||||||||
Python sebae* | x | x | x | x | x | |||||
Viperidae | ||||||||||
Atheris squamigera | x | x | x | |||||||
Bitis gabonica | x | x into East A | x | x | ||||||
Bitis nasicornis | x | x into East A | x | |||||||
Causus maculatus | x | x | x |
Numbers listed in parentheses refer to voucher specimens deposited in the
Testudines
Pelomedusidae
Pelusios rhodesianus Hewitt, 1927; (
Only two specimens were collected by local villagers in a pond, and this species was not frequently observed in aquatic habitats. Densities are probably low due to hunting pressure.
Kinixys belliana Gray, 1831
Carapaces of unconfirmed origin were for sale in local markets or in the possession of villagers. We never observed this species alive during our surveys. This species is apparently heavily hunted. Kinixys belliana is associated with open savannah habitats and is unlikely to occur in the closed-forest systems of the SPFE, where it might be replaced by the forest-dwelling Kinixys erosa. However, we have no indication yet of the occurrence of K. erosa in Uíge province. More field surveys and interviews with local hunters are required to confirm the presence of K. belliana within the wider SPFE area.
Crocodylidae
Crocodylus niloticus Laurenti, 1768
A single skull of unclear origin was found at a local village, but occurrence of this species in Uíge province is unconfirmed. Despite intensive searches and interviews with the local population, we were unable to unambiguously establish the existence of any crocodilian in the SPFE. However, it is likely that up to three species, Crocodylus niloticus, Mecistops leptorhynchus, and Osteolaemus tetraspis, occur or have occurred within the boundaries of the SPFE.
Agamidae
Agama agama -complex
This complex of species is mainly found in populated areas, such as within the provincial capital of Uíge, and largely associated with anthropogenic habitats, such as junkyards and buildings. Because of the unresolved taxonomy of this group in northern Angola, we refrain from assigning our records to a one of the currently recognized species.
Chamaeleo gracilis etiennei Schmidt, 1919; (
This subspecies is endemic to Angola and is previously mainly reported from open or bush savannah habitats. We observed that C. g. etiennei had a clear preference for open forest type habitats or habitats at the savannah-forest interface. We frequently recorded this species in degraded forests, mainly along roads.
Hemidactylus longicephalus Bocage, 1873; (
This species was recently revised by
Hemidactylus paivae Ceríaco, Agarwal, Marques & Bauer, 2020; (
Fig.
This speies was recently described by
Gerrhosaurus cf. nigrolineatus Hallowell, 1857; (
Fig.
The taxonomic status of Gerrhosaurus nigrolineatus is not well established and requires further research (
Holaspis guentheri Gray, 1863
This is only the third record of the species for Angola (
Panaspis cabindae (Bocage, 1866); (
The genus, of which P. cabindae is the type species, was recently revised by
Trachylepis cf. affinis (Gray, 1838); (
The taxonomic status of this species, particularly with respect to the relationship between its synonyms and the Angolan populations, is far from being resolved and requires a revision, in which Angolan material is included (
Trachylepis maculilabris (Gray, 1845); (
Fig.
Given its wide distribution, this may represent a complex of species. We collected a single specimen on the Kimpa Vita University campus in Uíge.
Varanus niloticus (Linnaeus, 1758); (
According to
Colubridae
Crotaphopeltis hotamboeia (Laurenti, 1768); (
This is one of the most widespread African snake species. A thorough revision recently assigned the Angolan populations to two distinct clades (“clade 2” and “clade 3” of
Dispholidus typus punctatus Laurent, 1955; (
Both currently recognized subspecies, D. t. typus and D. t. punctatus, are known to occur in Angola. However, we exclusively encountered D. t. punctatus, which is widespread throughout the province. A reassessment of the Angolan material and the distributional boundaries of the two subspecies is required. Several specimens were collected as roadkill.
Grayia ornata (Bocage, 1866); (
Fig.
Originally described from Angola by Bocage (1866), only a few individuals of this species were recorded since (
Philothamnus carinatus (Andersson, 1901); (
A single specimen, which is only the second record for Angola, was collected near Quimbele. This species is distinguishable from other members of its genus in having an undivided anal scale.
Philothamnus dorsalis (Bocage, 1866); (
A single specimen was collected near a village in the south-eastern foothills of the Serra do Pingano.
Thelotornis kirtlandii (Hallowell, 1844); (
This species is widespread throughout the province. We have several observations of T. kirtlandii from villages in which it was observed hunting for weaverbirds (Ploceus spp.).
Thrasops jacksonii Günther, 1895; (
This species has only been reported from Lunda Norte (
Toxicodryas blandingii (Hallowell, “1844” 1845); (
This species is until now only known from Lunda Norte (
Dendroaspis jamesoni (Traill, 1843); (
This species is recorded from sites only outside the core SPFE, including urban wasteland near the campus of Kimpa Vita University, Uíge.
Elapsoidea semiannulata Bocage, 1882; (
A single specimen was collected on the campus of Kimpa Vita University, Uíge.
Naja melanoleuca Hallowell, 1857; (
What was known as Naja melanoleuca has recently been split into four distinct species (
Boaedon angolensis Bocage, 1895; (
The material from Angola, including specimens collected in Uíge, is currently being revised (Hallermann et al. in prep.). We collected this species in a variety of open-savannah habitats near the city of Uíge and in the planalto de Mucaba.
Boaedon olivaceus (Duméril, 1856); (
The species has only been reported from Cabinda, and a single record exists from Lunda Norte. We collected two specimens near Maquela do Zombo, confirming the presence of B. olivaceus in Angola.
Lycophidion cf. multimaculatum Boettger, 1888; (
This species was previously often reported as L. capense. The differentiation and distributional limits of these two species require investigation.
Natriciteres olivacea (Peters, 1854); (
Only a few historical records of this species exist for Angola (
Python sebae (Gmelin, 1789)
This species is probably restricted to northern Angola and replaced by P. natalensis in the south. It is heavily hunted and frequently seen in bushmeat markets. We recorded this species in areas of wet savannah, which are often associated with larger river systems.
Atheris squamigera (Hallowell, “1854” 1855)
This is a true forest species, which is rarely recorded from Angola. Only four records exist, one of which is from Cabinda (
Bitis gabonica Duméril, Duméril & Bibron, 1854; (
Fig.
This species is commonly associated with forest-savannah mosaics of West and Central Africa. We recorded this species from forest fringes within an agricultural matrix in the Serra do Pingano. The distribution of the species across Angola is not well known and knowledge is fragmentary, but recent surveys by
Bitis nasicornis (Shaw, 1792); (
Our records from Uíge represent the third and fourth record of this species from Angola. These records are all based on animals killed by local hunters within small gallery forest remnants within a wet savannah matrix. So far, we have no records from within closed-forest systems of the SPFE, but it is likely that intensified surveys within the SPFE will eventually detect this species.
Causus maculatus (Hallowell, 1842); (
We have a single record, which is based on a road-killed individual from outside the SPFE.
Prior to the recent explorations outlined above, the amphibian diversity of Angola was considered moderate, with 101 amphibian species known. Of these, 11 species are endemic. As a comparison, the Democratic Republic of Congo has 224 amphibian species, with 48 of these endemic to that country (
Our systematic herpetological assessment for Uíge province yielded 47 amphibian species in various localities and ecosystems throughout the province (Table
Amphibian species recorded in the Serra do Pingano Forest Ecosystem (SPFE) and the wider province of Uíge (in alphabetic order) with occurrence in respective core areas (SU: Serra do Uíge, SP: Serra do Pingano, SV: Serra Vamba, UP: Uíge province outside SPFE), general range (ANG: Angola including Cabinda, WCA: West-Central Africa,.SSA: Sub-Saharan Africa (any range beyond WCA)) and general habitat type (PF: primary forest, DF: degraded forest, OH: open habitats, including natural savannahs as well as anthropogenic habitats and peri-urban sites). * = first country records for Angola.
Restricted to | Habitat | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Taxa | SU | SP | SV | UP | ANG | WCA | SSA | PF | DF | OH |
Amphibia | ||||||||||
Anura | ||||||||||
Pipidae | ||||||||||
Xenopus andrei * | x | x | x | |||||||
Xenopus mellotropicalis* | x | x | x | x | x | x | ||||
Xenopus petersii | x | x | x | |||||||
Arthroleptidae | x | x | ||||||||
Arthroleptis carquejai | x | x | x | x | x | x | ||||
Arthroleptis poecilonotus | x | x | x | x | x | |||||
Arthroleptis sylvaticus* | x | x | x | |||||||
Arthroleptis xenochirus | x | x into Malawi | x | |||||||
Cardioglossa gracilis * | x | x | x | x | ||||||
Leptopelis aubryi * | x | x | x | x | x | |||||
Leptopelis calcaratus* | x | x | x | x | ||||||
Leptopelis sp 1 | x | ? | ? | ? | x | x | ||||
Leptopelis millsoni* | x | x | x | x | x | |||||
Leptopelis ocellatus* | x | x | x | |||||||
Leptopelis sp.2 | ? | ? | ? | |||||||
Trichobatrachus cf. robustus* | x | x | x | |||||||
Bufonidae | ||||||||||
Sclerophrys pusilla | x | x | x | x | x | x | x | |||
Sclerophrys regularis | x | x | x | x | x | x | ||||
Sclerophrys cf. superciliaris* | x | x | x | x | ||||||
Sclerophrys sp.1 | x | ? | ? | ? | x | |||||
Dicroglossidae | ||||||||||
Hoplobatrachus occipitalis | x | x | x | x | x | x | ||||
Hyperoliidae | ||||||||||
Afrixalus osorioi | x | x | x | x | x | |||||
Afrixalus wittei | x | x Central A. into ANG | x | |||||||
Afrixalus aff. fulvovittatus | x | x | x | |||||||
Alexteroon hypsiphonus* | x | x | x | x | x | x | ||||
Hyperolius bocagei | x | x East to Uganda | x | |||||||
Hyperolius cinnamomeoventris | x | x | x | |||||||
Hyperolius dartevellei | x | x | x | |||||||
Hyperolius cf. guttulatus | x | x | x | |||||||
Hyperolius parallelus | x | x to Zambia & Namibia | x | |||||||
Hyperolius pardalis | x | x | x | |||||||
Hyperolius platyceps | x | x | x | |||||||
Hyperolius sp. 1 | x | ? | ? | ? | x | |||||
Kassina kuvangensis | x | x into Zambia | x | |||||||
Kassina senegalensis | x | x | x | |||||||
Phrynobatrachidae | ||||||||||
Phrynobatrachus cf. natalensis | x | ? | ? | ? | x | |||||
Phrynobatrachus cf. africanus | x | ? | ? | ? | x | x | ||||
Phrynobatrachus cf. mababiensis | x | ? | ? | ? | x | |||||
Phrynobatrachus aff. mayokoensis sp. 1* | x | x | ? | ? | ? | x | x | |||
Phrynobatrachus aff. mayokoensis sp. 2* | x | ? | ? | ? | x | x | ||||
Ptychadenidae | ||||||||||
Ptychadena anchietae | x | x | ||||||||
Ptychadena bunoderma | x | x into Zambia | x | |||||||
Ptychadena oxyrhynchus | x | x | x | x | x | x | x | |||
Ptychadena „mascareniensis“-complex | x | x | x | x | x | x | x | |||
Pyxicephalidae | ||||||||||
Amietia angolensis | x | x | x | x | x | |||||
Ranidae | ||||||||||
Amnirana albolabris | x | x | x | |||||||
Amnirana lepus | x | x | x | x | ||||||
Rhacophoridae | ||||||||||
Chiromantis rufescens* | x | x | x |
Species-richness estimators showed that our surveys yielded approximately between 70–80% of the species estimated for Uíge province, 62 ± 9.1 (Chao 2 ± SE), 62 ± 9.5 (Jackknife1 ± SE), 68.7 (Jackknife2 no SE available), and 54.0 ± 5.2 (bootstrap ± SE), and between 70–90% of estimated for the SPFE, 34.1 ± 5.5 (Chao 2 ± SE), 34.8 ± 4.8 (Jackknife1 ± SE), 37.6 (Jackknife2 no SE available), and 31.2 ± 2.6 (bootstrap ± SE). Together with the statistical species accumulation curves, which show a steady increase (Fig.
The amphibian fauna of the SPFE is comparatively rich and unique for the country, consisting of species that otherwise are only known from the Central African forest systems of Cameroon and/or Gabon (e.g. Trichobatrachus robustus, Xenopus andrei, and Sclerophrys superciliaris) or the Congolese rainforest realm, with faunal elements connecting to locations as far as the Albertine Rift in Eastern Africa (Ernst unpubl.). These elements make up roughly 80% of the recorded species, and represent exceptional range extensions in some cases. Apart from previously published records of the SPFE amphibians (
Numbers listed in parentheses refer to voucher specimens deposited in the
Anura
Pipidae
Xenopus andrei Loumont, 1983; (
This is a small member of the aquatic genus Xenopus. The specimen recorded in the SPFE represents the first record for Angola and south of the Congo Basin (
Xenopus mellotropicalis Evans, Carter, Greenbaum, Gvoždík, Kelley, McLaughlin, Pauwels, Portik, Stanley, Tinsley, Tobias & Blackburn, 2015; (
Fig.
This species is widespread throughout Uíge province, occurring from Quimbele in the far north, bordering the DRC, south to the SPFE. This species was always found to be associated with lotic habitats in both primary and disturbed forest (SPFE) and upland forest-savannah mosaics (Quimbele). Individuals were observed migrating into puddles along small roads and streamside ditches after and during heavy rain, where they likely feed on larvae of syntopic Ptychadena sp. This is the first record of the species for Angola.
Anuran species recorded within the SPFE a. Male Alexteroon hypsiphonus from transition between SP & SU b. female Chiromantis rufescens from SV c. female Xenopus mellotropicalis from transition between SP & SU d. female Amnirana lepus from SP e. male Cardioglossa gracilis from SP f. Sclerophrys cf. superciliaris from SP.
Xenopus petersii Bocage, 1895; (
This is a moderate- to large-bodied species. It is widespread throughout Angola. In Uíge, this species was exclusively found in heavily disturbed and/or anthropogenic aquatic habitats in open areas. These range from water-filled sand extraction pits in the moorlands of the Mucaba highlands to large, heavily polluted ponds (used for car washing, etc.) in open savannah areas near the town of Negage.
Arthroleptis carquejai Ferreira, 1906; (
Fig.
This is a bulky, medium-sized species. Males have only a slightly elongated middle finger. Arthroleptis carquejai was recently recognized as valid, distinct species, separate from A. variablilis. In Uíge province, A. carquejai was found in a variety of mainly disturbed forest habitats and along logging roads. It was frequently attracted by light-traps installed to catch nocturnal lepidopterans.
Anuran species recorded within and outside the SPFE a. Male Phrynobatrachus aff. mayokoensis sp. 1 from the planalto de Mucaba UP b. Arthroleptis carquejai from SV c. male Arthroleptis xenochirus from planalto de Mucaba with elongated middle finger d. female Arthroleptis xenochirus from planalto de Mucaba, found to be associated with ponerine ants e. undescribed Sclerophrys sp. from Quimbunda swamp UP f. male Kassina kuvangensis from moorland in planalto de Mucaba.
Arthroleptis aff. poecilonotus ; (
This is likely a species complex, which has been referred to as pseudo-mottled squeaker by
Arthroleptis sylvaticus (Laurent, 1954); (
This is a small, variable species with yellowish belly and mottled throat and ventro-laterals. So far, it has been exclusively found at forest edges near large calcareous inselberg outcrops in the Serra Vamba. This is the first record of this species from Angola.
Arthroleptis xenochirus Boulenger, 1909; (
Fig.
This is a well-documented species from north-eastern Angola. Males have extremely elongated middle fingers. In Uíge, A. xenochirus is restricted to more arid, open upland habitats in the Mucaba highland. Here, it is frequently found in small quarries, hiding underneath stones during the day and becoming active at dawn. In the planalto de Mucaba, a single female specimen (
Cardioglossa gracilis Boulenger, 1900; (
Fig.
The records from SPFE represent the southernmost ones for the genus Cardioglossa and, thus, are the first records from Angola. This species was recorded from two localities in the Serra do Pingano but may be more widespread in the province. In the SPFE, it was associated with closed forest habitats on steep terrain. Males were calling while hidden in vegetation or leaf-litter, usually in the vicinity but several meters from the banks of fast running creeks.
Leptopelis aubryi (Duméril, 1856); (
Fig.
There is a single record of the species from Angola, from outside Cabinda in the far north-eastern corner of Lunda Norte (
Reptile species recorded within the SPFE a. Hemidactylus paivae (“cave-morph”) from calcerous inselberg cave systems of SV b. Hemidactylus paivae (“forest-morph”) from forest patch in the same locality in the SV c. Juvenile Gerrhosaurus cf. nigrolineatus from SU. d. Trachylepis maculilabris from UP e. Bitis gabonica from SP f. Grayia ornata from SP.
Leptopelis calcaratus (Boulenger, 1906); (
Only a single record was found, from the Serra do Uíge near Cassechi, in a small forest patch near the Zeu River. Represents the first record for Angola.
Leptopelis millsoni (Boulenger, 1895); (
Fig.
Large-bodied females of this species were associated with dense forest. Within SPFE, the species is restricted to closed forest habitats in the vicinity of fast-running rainforest creeks. Males call from vegetation overhanging creeks. Locally, this species is fairly abundant. Coloration and pattern are extremely variable, usually brown-olive with dorsal crossbars, but also uniform green with white and yellow bands. The ventral side is mostly uniform yellowish-white but sometimes also bright orange or with dark-reticulations on a white background. Individuals from Uíge may be part of a larger unresolved complex in need of a thorough revision (Bell et al. in prep.).
Leptopelis ocellatus (Mocquard, 1902); (
This is a small species mainly found in more open, savannah-like habitats, where males call from low vegetation, often in the vicinity of larger lentic aquatic habitats. There is pronounced sexual size dimorphism. An amplectant pair (
Leptopelis sp. 1; (
Fig.
This possibly undescribed species superficially resembles L. jordani but genetically does not match any known taxon for which sequence data are available. A single specimen was found in a forest patch connecting the Serra do Uíge with the Serra do Pingano.
Leptopelis sp. 2; (
This species superficially resembles L. bocagei but genetically does not match any known taxon for which sequence data are available. A single specimen was collected in the north-eastern municipality of Milunga.
Trichobatrachus cf. robustus Boulenger, 1900; (
A single adult and several tadpoles were recorded in the Serra do Pingano. SPFE populations belong to a lineage that is genetically distinct from populations in Cameroon and Gabon. Further studies are required to clarify the status of the SPFE populations (
Sclerophrys pusilla (Mertens, 1937); (
The species was previously recorded as S. maculata but removed from synonymy by
Sclerophrys regularis (Reus, 1833); (
Unlike the previous species, S. regularis was exclusively found in disturbed or open savannah habitats, including rural settlements and peri-urban or urban areas. The taxonomic boundaries between S. regularis, S. gutturalis, and even S. pusilla in Angola are poorly understood and further studies are needed to clarify the actual status of the northern Angolan populations.
Sclerophrys cf. superciliaris (Boulenger, 1888); (
Fig.
This species was recorded from two localities within the SPFE, always associated with fast-flowing streams. Adults were frequently found at night on rocks in the middle of streams, and during the day, they were sleeping on branches overhanging these streams. Freshly metamorphed toadlets were recorded in November. Although this species was previously collected in the Angolan provinces of Cuanza Norte and Huambo during the “Deutsche Angola Expedition 1952–1953”, with vouchers deposited in the herpetological collection of the Zoologisches Museum Hamburg (
Sclerophrys sp. 1; (
Fig.
A single specimen of a possibly undescribed species Sclerophrys was recorded from Quimbunda swamp near Negage. The morphology and habitus of this taxon superficially resembles Sclerophrys gracilipes, but it does not genetically match any known species for which sequence data are currently available.
Hoplobatrachus occipitalis (Günther, 1858); (
This species is widespread throughout the province. We previously recorded this species exclusively from open savannah type and degraded habitats near larger rivers (Ernst unpubl.). In 2019, the species was found in an area of the Serra do Pingano that had been forested but was cleared and converted to a mixed crop plantation in 2017. This species was absent at this site in all previous recording years, and it seemed to have replaced the large-river associated pyxicephalid Amietia angolensis, which was previously recorded and observed to reproduce in that segment of the river. Whether this absence is the result of direct competition, or even larval predation by the carnivorous tadpoles of H. occipitalis, remains unclear. Amietia angolensis was still recorded in other upstream segments of this river still bordered by degraded forest remnants; this indicates that the replacement process is at least in part directly driven by habitat alteration.
Afrixalus osorioi (Ferreira, 1906); (
In Angola, this species was previously only recorded from its type locality at Quilombo, Cuanza Norte, but apparently it is more widespread. We frequently recorded this species in degraded forest.
Afrixalus wittei (Laurent, 1941); (
This species was recorded in open savannah and farm bush habitats, even in urban areas such as the campus of Kimpa Vita University in Uíge.
Afrixalus aff. fulvovittatus sensu
This species was found in wet savannahs and open grasslands in the planalto de Mucaba. Its status and distribution remain unclear and require further investigation. Until the taxonomic status of the species recorded in Uíge has been clarified, we tentatively assign it to the Afrixalus aff. fulvovittatus lineage as construed by
Alexteroon hypsiphonus Amiet, 2000; (
Fig.
The Angolan records represent the southernmost records of the genus and the first records for the country. This species occurs throughout the SPFE but is restricted to riparian habitats in both primary and degraded forests. Males were heard calling from trees overhanging streams by several metres. Calling perches were very often in myrmecophytic Macaranga sp. trees. Therefore, our attempts to catch individuals often resulted in attacks by associated ants. Whether this calling site selection was coincidental or represents a predator avoidance strategy is unclear and requires testing. Although the morphology of males of the SPFE population largely corresponds to
Hyperolius bocagei Steindachner, 1867; (
This species was exclusively found in open savannah habitats outside the core SPFE area. It was previously suggested to be part of the Hyperolius viridiflavus superspecies (
Hyperolius cinnamomeoventris Bocage, 1866; (
This species was recorded from degraded open habitats in peri-urban settings, such as the campus of Kimpa Vita University, and open savannah habitats in the northern region of Quimbele.
Hyperolius dartevellei Laurent, 1943; (
This is a small species of the nasutus-complex and was removed from the synonymy of Hyperolius adspersus by
Hyperolius cf. guttulatus Günther, 1858; (
This is a bulky, variable species, which was recorded from open wet and mixed forest savannah in the northern region of Quimbele. The main color patterns observed were either uniform yellowish or orange-brown with small dark spots. Both sexes lack the dark stripe extending from snout tip to eye, typical for H. guttulatus or H. phantasticus. Hyperolius cf. guttulatus also differs from H. phantasticus in its ventral coloration, which is uniformly translucent in the former and yellowish with black spots as in the later.
Hyperolius parallelus Günther, 1858; (
This species is widespread throughout the province in a wide array of open and degraded habitats, including peri-urban farming areas with fishponds. It is a greatly variable species.
Hyperolius pardalis Laurent, 1948; (
This specie was recorded from open wet and mixed forest savannah in the northern region of Quimbele, where it was syntopic with Hyperolius cf. guttulatus and Kassina senegalensis. Individuals in these populations differ in coloration from Cameroonian individuals by having a darker, copper-brown dorsal coloration (versus cream brown to yellowish in the Cameroonian ones) and smaller white spots on venter extending ventrolaterally.
Hyperolius platyceps (Boulenger, 1900); (
This species was only recorded from Mucaba swamp, planalto de Mucaba, and there only within a tiny swamp forest fragment that is severely impacted by logging. This is the only forest fragment remaining in an otherwise cleared moorland system which is heavily exploited for sand extraction for road construction.
Hyperolius sp. 1; (
This is the only Hyperolius species recorded from dense forest within a core SPFE locality connecting the Serra do Pingano with the Serra do Uíge. Males emit high-pitched metallic calls that are tonally similar to the syntopically occurring Alexteroon hypsiphonus. The single individual collected superficially resembles Hyperolius koehleri but shows >10% sequence divergence in the 16S gene with sequences publicly available on GenBank.
Kassina kuvangensis (Monard, 1937); (
Fig.
This species was only recorded from Mucaba swamp, planalto de Mucaba but is probably more widespread throughout Uíge province. Kassina kuvangensis was previously thought to be restricted to south-central Angola and northern Zambia, but it apparently has a much wider distribution. It has also been recorded in Lunda Norte (W. Conradie pers. comm.). Calling males in the Mucaba swamp population were concealed in small holes or burrows near sedge tussocks. Whether the Mucaba swamp population is a disjunct northern population or continuous with populations of central Angola and northern Zambia in the south to Uíge in the north, needs to be clarified by surveys in the interlying areas.
Kassina senegalensis (Duméril & Bibron, 1841); (
This is the most widespread Kassina species, but across its range it likely comprises several cryptic species. Populations in different geographic regions, including those from Angola, require a thorough revision. In Uíge, the species was encountered in open wet savannahs in Quimbele, planalto de Mucaba, and savannah patches between M’Banza Congo and Songo, as well as the north-western fringes of the Serra Vamba.
Phrynobatrachus cf. natalensis (Smith, 1849); (
In the SPFE, this species was only found in roadside ditches and puddles in disturbed forest and open habitats. It is variable in color, but most frequently there is a broad, green dorsal band. Phrynobatrachus natalensis comprises several cryptic species. The Angolan records have been referred to the “natalensis-A” lineage by
Phrynobatrachus cf. africanus (Hallowell, 1858); (
This is a compact-bodied species. There are only a few records from the SPFE, all from degraded or recently cleared forest. This species is apparently locally not abundant, but it may be more widely distributed than currently known.
Phrynobatrachus cf. mababiensis FitzSimons, 1932; (
This widespread species occurs throughout Uíge province, except in fully forested areas. It is restricted to open savannahs and heavily disturbed grasslands, such as in the planalto de Mucaba. It is locally very abundant. Males were heard calling from the ground near small puddles and water-filled rills.
Phrynobatrachus aff. mayokoensis sp. 1; (
Fig.
A single individual was collected from the planalto de Mucaba, outside the SPFE core, in a freshly cleared forest patch near a large pond. Superficially this individual resembles P. mayokoensis but shows approximately 6% divergence in the 16S gene sequence (Ernst unpubl.); additionally, it can be differentiated by several morphological characters: there are three regular tubercles on the eyelid; there is a broad orange transversal band on the back but a red-orange spot is lacking on the thighs; and the throat is yellowish but with the belly uniform white. This probably is an undescribed species.
Phrynobatrachus aff. mayokoensis sp. 2; (
Two individuals, resembling P. mayokoensis, were collected, in the planalto de Mucaba and outside the SPFE core. These were found in a freshly cleared forest patch near a large pond. Superficially resembling P. mayokoensis, these individuals (compare P. aff. mayokoensis sp. 1) show approximately 4.5% divergence in the 16S gene sequence (Ernst unpubl.) and are also differentiated by several morphological characters: the eyelid is warty but without regular tubercles or spines; the dorsal coloration is uniformly olive-brown with irregularly arranged orange tubercles, and there is a narrow, white dorsal line; and the ventral coloration is white, with the throat and first third to half of the body bearing irregular black blotches. The relationship of this species to P. mayokoensis and P. aff. mayokoensis sp. 1 is in need of clarification.
Ptychadena anchietae (Bocage, 1868); (
In Uíge province, this species is restricted to open savannah habitats outside core SPFE sites. Individuals from Angolan populations are clearly distinct from those of East African populations. The P. anchietae complex currently comprises at least three distinct lineages in East Africa, including a separate lineage in Mozambique. Therefore, Angola populations likely represent the nominal P. anchietae (
Ptychadena bunoderma (Boulenger, 1907); (
This is a very small and compact species. It is restricted to open savannah habitats outside core SPFE sites. Individuals from Uíge province mostly correspond to the holotype, both morphologically and genetically (
Ptychadena oxyrhynchus (Smith, 1894); (
This species was recorded in both open savannah habitats and degraded forest. In the latter, it was found mainly along roads. Ptychadena oxyrhynchus is a species complex, which consists of at least four deeply divergent lineages having distinct geographic ranges (
Ptychadena “ mascareniensis ” complex; (
This taxon was recorded in both open savannah habitats and degraded forest. In the latter, it was mainly along roads. Ptychadena mascareniensis is a complex of species which has not been fully resolved (
Amietia angolensis (Bocage, 1866); (
This species is an Angolan endemic (
Amnirana albolabris (Hallowell, 1856); (
In Uíge, this species was frequently found in small, riparian forest pockets in otherwise open, degraded savannah habitats; however, it was also found in agricultural areas near fishponds. This species ranges widely from Uíge in the south to Maquela do Zombo in the north. Northern Angolan individuals are part of a cryptic complex of several species (
Amnirana lepus (Andersson, 1903); (
Fig.
This species has marked sexual size dimorphism, with females larger. It was found exclusively in closed forest, along creeks and waterfalls, within the SPFE. Tadpoles were frequently found in larger pools at the bottom of waterfalls. The population in the SPFE probably represents the southernmost distribution of the species (
Chiromantis rufescens (Günther, 1869); (
Fig.
With the exceptions of perhaps Lunda Norte (
Evidence from our herpetofaunal field surveys in the SPFE supports an assumed Late Quaternary connection with Central African forest systems and its potential role as late- Pleistocene forest refuge. Our results highlight the prominent role of northern Angola, and the SPFE in particular, in protecting and safeguarding significant and unique portions of Angola’s biodiversity. However, if deforestation and habitat degradation continue at the alarming rates observed during 2018 and 2019, this exceptional African rainforest ecosystem, including much of its amphibian and reptile diversity, will be lost forever. A closed rainforest site, which connected the Serra do Uíge with the Serra do Pingano, where we visited in 2016, and where Alexteroon hypsiphonus was recorded for the first time in Angola, had been cleared for agricultural use two years later (Fig.
Pristine and disturbed habitats in the Serra do Pingano Forest Ecosystem (SPFE). a. Intact forest cover in the Serra do Pingano. b. Riparian forest system with waterfall on steep terrain in the Serra do Pingano c. Clearcut after slash-and burn acitivity at higher elevations (upper slope and ridge) of the Serra do Pingano. d. Intentional burning on the northeastern slope of the Serra do Pingano e. Mosaic of previously burnt and still forested patches on northeastern slope of the Serra do Pingano f. Freshly cleared forest patch at transition between the Serra do Pingano and the Serra do Uíge, now used fro plantation agriculture. Locality, in which several amphibian species (e.g. Alexteroon hypsiphonus, Sclerophrys cf. superciliaris) had been recorded for the first time in Angola only 3-4 years prior to the impact. .
In contrast to large mammals and more mobile organisms, such as birds, habitat size seems less important than habitat diversity in conserving amphibian diversity (
Thus, the highest priority should be given to halting or strictly controlling ongoing encroachment and uncontrolled farming activities, such as slash-and-burn agriculture, as well as logging. One legislative issue requiring attention involves the frequent noncompliance of official forestry laws and uncontrolled logging outside designated times. Core areas surrounding lotic water systems (rivers, streams, waterfalls, etc.) are particularly sensitive and crucial to the protection of several high-priority species and should be spared from logging and burning. Improvement of infrastructure in the SPFE, especially road construction on the southern flank of the Serra do Pingano facing the Serra Vamba, is another serious concern. By allowing for easy access to forest sites, new roads into previously inaccessible forest lead to numerous impacts, including a massive increase in the illegal and unsustainable harvest of forest resources, especially bushmeat (
In conclusion, the SPFE has an extraordinary conservation potential for amphibian and reptile diversity both in a national and pan-African context. The species composition in the SPFE is unique and consists of a high proportion of forest specialists with restricted ranges and found nowhere else in the country. Several species and species complexes require taxonomic revision, and additional undescribed species are to be expected pending results of studies already underway. Species estimates clearly show that more species are likely to be detected if survey efforts are increased. The newly recorded species shed light on the forest history of the whole region. If the newly obtained distributional data are included in larger biogeographic models, they may contribute to solving open questions concerning early-Pleistocene glaciation dynamics which are assumed to have affected the recent and historic extent of the Guineo-Congolian tropical forest phytogeographic region. This is particularly important as evidence accumulates that northern Angolan rainforests may have served as a refugium for forest taxa during periods of dramatic climatic fluctuations. This emphasizes the paramount importance of the remaining forest fragments, such as those still existent in the SPFE. The SPFE is currently threatened by increasing agricultural encroachment and uncontrolled timber extraction in the remaining forest patches, whose extent is dwindling at an alarming rate. These threats will likely push some of the rarer species to the brink of extinction within the next decade and ultimately jeopardize the long-term viability of the entire ecosystem and the services it provides to human wellbeing. In an urgent need to strictly protect the remaining forests, destructive activities need to be controlled or abandoned. Our knowledge of the biodiversity contained in forest fragments is still patchy. Rapid biodiversity surveys, in combination with modern scientific techniques and long-term monitoring routines, are urgently needed to obtain a better understanding of the largely underappreciated biodiversity in these fragile forest remnants, to resolve both taxonomic and biogeographic questions, and to provide the basis for a more comprehensive assessment of Angola’s biodiversity in general, which is a prerequisite for the development of sound and sustainable conservation strategies of its most precious and unique ecosystems. The Serra do Pingano Forest Ecosystem is central in developing and enhancing these strategies. Its protection will be the major challenge in the battle of ideas aimed at safeguarding Angola’s biodiversity treasure trove for future generations of Angolan scientists who may eventually contribute to solving the pressing questions that will ultimately help fighting the life-threatening global biodiversity crisis that we experience today.
Fieldwork was made possible through the help of the University of Kimpa Vita in Uíge and partially funded through a travel grant from the German Academic Exchange Service (DAAD) and the “strategic partnership” program of the TU Dresden. Final surveys were supported by the Ministério do Ambiente - Instituto Nacional da Biodiversidade e Áreas de Conservação (INBAC) within the project agenda “Expansão e Fortalecimento do Sistema de Áreas Protegidas em Angola” through a grant provided by GEF under the auspices of UNEP. We particularly thank J. Lau for support in the field. Permission to conduct biodiversity research in Angola and to export specimens was granted by the Instituto Nacional da Biodiversidade e Áreas de Conservação (INBAC), Ministério do Ambiente, República de Angola and the Gabinete Provincial da Agricultura, Pecuári e Pescas Do Uíge under permission numbers 122/INBAC.MINAMB/2013, no. 17/014, no. 02/018; no. 05/2019. The lab work was supported by a grant from the Paul-Ungerer-Stiftung. A. Channing, W. Conradi, E. Greenbaum, and G. Jongsma commented on an earlier version and significantly improved the manuscript through their especially useful and constructive remarks.
We dedicate this publication to William (Bill) Roy Branch (1946–