Herpetology Notes, volume 14: 1105-1109 (2021) (published online on 20 August 2021)

Updated geographic distribution of aethiopissa (: ) for , with comments on diet

Werner Conradie1,2,*, Rogério Ferreira3, Pedro Vaz Pinto3,4,5, and Javier Lobón-Rovira4

Africa hosts a remarkable diversity of with Dagger-tooth tree snakes, Rhamnophis Günther, approximately 596 recognised corresponding to 1862, is a harmless, diurnal and arboreal widely ca. 15.2% of world diversity (Uetz et al., 2021), inhabiting distributed in central and western Africa (Spawls and diverse biomes from deserts to rainforests. However, Branch, 2020). It belongs to the Tribe Dispholidini for most species, accurate geographic distributions and (Bourgeois, 1968) where it was regarded as a close ecological information are missing. Snakes are one of relative of the genus (Broadley and Wallach, the most challenging groups of squamates to survey due 2002). In a more recent phylogenetic study, it has to their low probability of detection (Steen, 2010; Durso been found that Rhamnophis is the sister clade to a et al., 2011), and species records are generally derived larger clade containing Dispholidus, Thelotornis, and from opportunistic encounters. The limited number of Xyelodontophis, with Thrasops being basal to the records from remote areas often predicted to be whole group (Eimermacher, 2012). Within this genus species-rich, has left gaps in our understanding of snake two species are currently recognised: Rhamnophis distribution (Steen, 2010). This is the case for vast areas aethiopissa Günther, 1862 and Rhamnophis batesii in Angola, where herpetological surveys were curtailed (Boulenger, 1908). They are morphologically for several decades due to civil war and social instability distinguished by the number of mid-dorsal scale rows (Huntley and Ferrand, 2019), and records for many [15–19 in R. aethiopissa vs 13 in R. batesii], number of snake taxa remain rare and scattered (Branch, 2018; subcaudal scales [117–159 in R. aethiopissa vs 91–114 Marques et al., 2018). Despite that Angola remains in R. batesii], cloacal scales [divided in R. aethiopissa poorly surveyed, the total number of currently reported vs entire in R. batesii], number of maxillary teeth [30+3 species is ca. 130 (Branch et al., 2018, 2019; Hallerman to 35+3 in R. aethiopissa versus 17+3 to 20+3 in R. et al., 2020; Conradie et al., 2020), one of Africa greatest batesii], and occipital scales [2 large occipital scales snake species diversity (Marias, 2011; Branch, 2018; in R. aethiopissa vs 3–4 in R. batesii] (see Loveridge, Uetz et al., 2020). 1944). Rhamnophis aethiopissa is widely distributed from eastern Kenya to northern Angola and adjacent Zambia, and currently comprise three subspecies: R. a. aethiopissa Günther, 1862, R. a. elgonensis Loveridge, 1 Port Elizabeth Museum, P.O. Box 13147, Humewood 6013, South Africa. 1929 and R. a. ituriensis Schmidt, 1923. Rhamnophis 2 Department of Nature Conservation Management, Natural a. aethiopissa is widely distributed across western and Resource Science and Management Cluster, Faculty of central Africa, R. a. elgonensis is known from western Science, George Campus, Nelson Mandela University, Uganda to western Kenya, while R. a. ituriensis is George, South Africa. distributed from eastern Democratic Republic of the 3 Fundação Kissama, Rua 60 Casa 560, Lar do Patriota, , Congo to northern Angola (Laurent, 1950, 1954, 1964; Angola. Thys van den Audenaerde, 1966) and north-western 4 CIBIO Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Rua Padre Armando Zambia (Broadley, 1990; Bittencourt-Silva, 2019). Quintas, Campus de Vairão, Vairão 4485-661, . There is morphological variability within the different 5 TwinLab CIBIO/ISCED, Instituto Superior de Ciências da subspecies and samples from these subspecies have not Educação da Huíla, Rua Sarmento Rodrigues s/n, , yet been analysed molecularly (Eimermacher, 2012). Angola. Consequently, some authors consider these subspecies * Corresponding author. E-mail: [email protected] as being invalid (Chippaux and Jackson, 2019). © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. Hellmich (1957) assigned his material collected from 1106 Werner Conradie et al.

Angola to R. a. aethiopissa. While other researchers, we provide an updated distribution for R. aethiopissa based on the lower number of midbody scale rows (15) for Angola (Fig. 1) and provide evidence of two new and that the lower postocular is in contact with only two country records for this species. supralabials, placed his material within R. a. ituriensis On 13 September 2016, a road-killed snake ascribed (Laurent, 1950, 1954, 1964; Thys van den Audenaerde, to Rhamnophis aethiopissa (species identification based 1966). Based on these morphological evidences, we can on the unique head scalation: 8 upper labials and the confidently assign all the historical Angolan material lower postocular only in contact with two upper labials) to R. a. ituriensis. Although due to the lack of a tested was collected by PVP close to Piri, subspecies status, we prefer to refer to this material by (-8.59472°, 14.33611°) and subsequently deposited its binominal name, R. aethiopissa. at the Port Elizabeth Museum (catalogue number Records of Rhamnophis aethiopissa from Angola PEM R26383 – head only). This roadkill was found are very limited (seven museum records in total) and at the edge of a degraded semideciduous moist forest scattered (four unique localities) based on historical block, about 5 km west of Piri- (Hellmich, data from the late 1950s to early 1960s (Laurent, 1950, 1957). More recently, on 5 February 2021, around 1954, 1956; Thys van den Audenaerde, 1966; Hellmich, 12:30 pm, a record of R. aethiopissa was documented 1957; Marques et al., 2018; Table 1). Three of the four by RFF in riverine forest along River, historical localities are located in Lunda-Norte Province Province (-8.87172°, 16.11599°). This record has been in north-eastern Angola, while the fourth locality is registered on iNaturalsit (https://www.inaturalist.org/ located in Piri (Hellmich, 1957), in Bengo Province, observations/69251335; Fig. 1A–B). The latter record ~650 km west from previous records. In this work provides an intermediate record bridging a distributional

Figure 1. A – Rhamnophis aethiopissa Günther, 1862 from Luando River, . B – individual of R. aethiopissa feeding on a Hyperolius angolensis Steindachner, 1867, C – updated distribution of R. aethiopissa for Angola. Red stars – new records; yellow dots – historical records. Map colours represent main Angolan ecoregions as defined by Burgess et al. (2004) underlaid by elevation: 1 – Angolan scarp savannah and woodlands, 2 – Western Congolian forest-savannah, 3 – Southern Congolian forest-savannah, 4 – Angolan wet miombo woodlands, 5 – Central Zambezian wet miombo woodlands, 6 – Angolan montane forest-grassland, 7 – Namibian savannah woodlands, 8 – Kaokoveld desert, 9 – Angolan Mopane woodlands, 10 – Zambezian Baikiaea woodlands, 11 – Zambezian flooded grasslands, 12 – Western Zambezian grasslands, 13 – Atlantic Equatorial Coastal Forests. Updated geographic distribution of Rhamnophis aethiopissa for Angola 1107

TableTable 1 1. .Records Records ofof RhamnophisRhamnophis aethiopissa aethiopissa for forAngola. Angola.

Locality Latitude Longitude Source Piri-Dembos, Kwanza-Norte Province -8.56667 14.50000 Hellmich, 1957 ‘de la Mussungue (affluent de la Luachimo) pres de ’, Lunda-Norte Province -7.41667 20.83333 Laurent, 1950; Thys van den Audenaerde, 1966 Dundo, Lunda-Norte Province -7.36667 20.83333 Laurent, 1954, 1964 Calanda, Camissombo, Lunda, Lunda-Norte Province -8.15000 20.66667 Laurent, 1964 between Ukua and Piri, Bengo Province -8.59472 14.33611 This study

Luando River, Malanje Province -8.87172 16.11599 This study

gap for the species in northern Angola. This brings the dissected specimens of R. aethiopissa (N = 9) and R. total number of species records for Angola to nine batesii (N = 5) deposited in the PEM (see material originating from six unique localities (Fig. 1C). examined). Only five of these individuals had something The Rhamnophis aethiopissa individual from Luando in their stomach (Table 2). All intact prey items were River was observed hunting prey among low tree ingested headfirst, similar to the new observation. The branches during the day. This individual successfully stomach contents of two of the R. batesii specimens caught and consumed an adult Angolan reed frog, contained unidentified anuran remains, while two of the Hyperolius angolensis Steindachner, 1867 (Fig. 1B). R. aethiopissa and one R. batesii specimens contained Although the genus Rhamnophis has been referred prey remains that we could identify to genus-level to as preying mostly on arboreal species (Luiselli et (Hyperolius sp. and Leptopelis sp.). The Leptopelis sp. al., 2000), only a single primary record exist of them record have previously been documented as prey item feeding on frogs (see Table 2 for summary; Burger et for this species (Burger et al., 2004), therefore these new al., 2004). The only study on the diet of Rhamnophis observations further support the notion that Rhamnophis recorded prey items such as shrews, birds and species prey on arboreal amphibians. (Gekkonidae, Chameleonidae and Agamidae), but no Here we provide an updated distribution of amphibians were recorded (Luiselli et al., 2000). Rhamnophis aethiopissa in Angola. These records To investigate the diet of Rhamnophis further, we suggest that the species is likely widespread, and well-

TableTable 2 2.. SummarySummary of of all all dietary dietary records records of Rhamnophis of Rhamnophis species species sourced sourced from literature from literature and this study. and this study.

Species Description Prey Locality Source Amphibia

R. aethiopissa Hyperolius angolensis Luando River, Malanje Province, Angola This study, specimen not collected

R. aethiopissa male, 838+495 mm, 95 g Leptopelis sp. Doussala, Gabon Burger et al., 2004; this study (PEM R05256) R. batesii female, 692+331 mm, 35 g Hyperolius sp. Rabi, Gabon This study (PEM R05399) R. batesii female, 941+245t mm, 105 g Unidentified Anuran Bayanga, Central African Republic This study (PEM R26329) R. batesii female, 846+422 mm, 65 g Unidentified Anuran Bayanga, Central African Republic This study (PEM R26328) Reptillia R. aethiopissa Rhampholoen sp. (2) Nigeria Luiselli et al., 2000

R. aethiopissa Trioceros owenii Nigeria Luiselli et al., 2000

R. aethiopissa Hemidactylus fasciatus Nigeria

R. aethiopissa Agama agama Nigeria Luiselli et al., 2000

R. aethiopissa Gekkonidae Nigeria Luiselli et al., 2000 Mammalia

R. aethiopissa Crocidura sp. Nigeria Luiselli et al., 2000 Aves

R. aethiopissa Pogoniulus sp. (2) Nigeria Luiselli et al., 2000

R. aethiopissa Sylvietta virens Nigeria Luiselli et al., 2000

R. aethiopissa Cisticola sp. Nigeria Luiselli et al., 2000

R. aethiopissa Nectarinia sp. Nigeria Luiselli et al., 2000

R. aethiopissa unidentified hatchling Nigeria Luiselli et al., 2000

R. aethiopissa unidentified adult Nigeria Luiselli et al., 2000

1108 Werner Conradie et al. adapted to the Congolese Forest Biome across northern Huntley, B.J., Ferrand, N. (2019): Angolan Biodiversity: Towards a Angola, despite the few existing records. We expect that modern Synthesis. In: Huntley, B.J., Russo, V., Lages, F., Ferrand, the species might occur in remnant forest blocks along N. (eds). Biodiversity of Angola. Science and Conservation: A Modern Synthesis. Springer Nature, Champ. the Angolan western escarpment, where other arboreal Laurent, R.F. (1950): Reptiles et Batraciens de la region de Dundo forest snakes reach their southernmost range limit (Angola du Nord-Est). Publicações culturais da Companhia de (e.g., Dendroaspis jamesoni, Toxicodryas blandingi), Diamantes de Angola 10: 7–17. although it has not been recorded south of the Cuanza Laurent, R.F. (1954): Reptiles et Batraciens de la région de Dundo River. Finally, we provide evidence that R. aethiopissa (Angola) (Deuxième Note). 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Material examined in this study. Rhamnophis aethiopissa (N = 9): PEM R26407, Niapu, Democratic Republic of the Congo; PEM R19218, Tokedah Mine Entrance, Liberia, 7.4500, -8.63533; PEM R05206, south of Gamba. Gabon, -2.75222, 10.02000; PEM R05265, 11 km NW of Doussala, Gabon, -2.28333, 10.48333; PEM R05358, Rabi (Shell Gabon), Gabon, -1.94250, 9.85250; PEM R05382, Rabi (Shell Gabon), Gabon, -1.93417, 9.87556; PEM R24957, Rabi Road towards Didjombi, Gabon, -1.88250, 9.86194; P 0846 (RBINS), Gabon; PEM R22378, Niari District, Republic of the Congo. Rhamnophis batesii (N = 5): PEM R26328, Bayanga, Central African Republic, PEM R26329, Bayanga, Central African Republic; PEM R05359, Rabi (Shell Gabon), Gabon, -1.94694, 9.87889; PEM R05399, Rabi (Shell Gabon), Gabon, -1.84806, 9.85972; P 0847 (RBINS), Gabon.

Accepted by Angelica Crottini