Herpetology Notes, volume 13: 937-939 (2020) (published online on 16 November 2020) First records of Rugege forest squeaker Arthroleptis adolfifriederici (Amphibian: Anura: Arthroleptidae) from Volcanoes National Park, Rwanda, since 1941 Jean Claude Twahirwa1,*, Emmanuel Faida1, Deogratias Tuyisingize1, and Yntze van der Hoek1 The first record of Rugege forest Squeaker, Arthroleptis recorded species, even compared to other species of the adolfifriederici Neiden, 1911 from Volcanoes National same genus. For example, there are only five confirmed Park (VNP), part of the Virunga Massif, Rwanda stems records for Bwindi Impenetrable Forest in Uganda from specimens collected in 1941 (De Witte, 1941). (Drewes and Vindum, 1991; IUCN, 2014) and one from Since then, there have been no further published records Nyungwe National Park Rwanda (Menegon, 2008). of its presence within VNP or the wider Virunga Massif, Recent surveys in other forested areas in the region, despite the increased prevalence of herpetological notably Gishwati-Mukura National Park, returned no surveys in the region in the past decades (Roelke et al., records of A. adolfifriederici (LAFREC, 2018). Given 2009; van der Hoek et al., 2019). Here, we describe an this lack of data on the species, it is difficult to assess observation of a female specimen at the edge of a small the species’ population status, reflecting the general montane wetland, at a relatively high elevation (2,700 state of research on amphibians in Africa (Wake and m. a.sl.), halfway between the volcanic peaks of Mount Vredenburg, 2007). Bisoke and Mount Sabyinyo in VNP in 2020. As this species could be negatively affected by ongoing The anuran family Arthroleptidae are distributed deforestation and deterioration of its habitat (REMA, across most of sub-Saharan Africa (Blackburn et al., 2015), it is important to monitor its occupancy of 2010) and consists out of eight currently recognised different parts of its range. During a visit to the wetlands genera, of which two (Arthroleptis and Leptopelis) have of VNP in January 2020, for the annual monitoring of a confirmed historical presence in the Central African amphibians (see van der Hoek et al., 2019 for more Virunga Massif on the borders of Uganda, Democratic information and methods), we opportunistically Republic of the Congo, and Rwanda. In this region, encountered an individual in a bamboo forest at the or at least in the section covered by VNP, we see that edge of the Kato wetland (-1.400552°S, 29.551902°E, specimens belonging to genus Leptopelis are relatively 2,700 m a.s.l.) in the ‘saddle’ between the volcanic abundant and common (e.g., Roelke et al., 2009; van peaks of Mount Bisoke and Mount Sabyinyo. The der Hoek et al., 2019) but that records of Arthroleptis specimen was found moving slowly among dry leaf are limited to one historical record of A. adolfifriederici litter under a closed canopy bamboo (Yushania alpina) (also known as the Adolf’s Squeaker, Rugege Forest stand approximately one meters from the forest clearing Squeaker, or Adolf Friedrich’s Squeaker) from 1941 created by the wetland. We identified this specimen as (De Witte, 1941). A. adolfifriederici due the following combination of Although the conservation status of A. adolfifriederici features: 1) less prominent tympanum, 2) the light colour is listed as Least Concern (IUCN, 2014) due to the of their throat, and 3) a lack of well-defined black spots relatively large extent of its occurrence, it is a rarely on the lateral surface of their body (Fig. 1; Blackburn et al., 2009). We considered this specimen to be a female due to the presence of eggs, the lack of spines on the third finger of the hand, and its relatively large body size (Blackburn, 2009b). Males of this species have a snout– 1 Dian Fossey Gorilla Fund International Karisoke Research vent length (SVL) of less than 35 mm whereas females Center, Musanze, Rwanda. can measure up to 42 mm (Blackburn et al., 2009). * Corresponding author. E-mail: [email protected] Using an analogue calliper (measuring to the nearest 938 Jean Claude Twahirwa et al. Figure 1. Dorsal (A) and ventral (B) photos of a female Arthroleptis adolfifriederici recorded from Volcanoes National Park, Rwanda. 0.5 mm), we found that the recorded specimen was 37.5 Acknowledgments. We thank the Rwanda Development Board mm long (SVL), with a tibia length of 20.5 mm, inter- (RDB) for granting us permission to conduct field work in the orbital distance of 5.0 mm, eye diameter of 4.0 mm, Volcanoes National Park. We thank Corey Roelke for confirming our initial identification of this frog and an anonymous reviewer for head length of 11.5 mm, and head width (HW) of 11.0 constructive comments on an earlier draft of this manuscript. mm. We approximated the mass of this individual using a 100 g Pesola spring scale (rounding to the nearest 0.5 References gram) to be 13.0 g. Blackburn, D.C. Gvoždík, V., Leaché, A.D. (2010): A new This new record of A. adolfifriederici constitutes squeaker frog (Arthroleptidae: Arthroleptis) from the mountains a rediscovery of the presence of this species within of Cameroon and Nigeria. Herpetologica 66(3): 335–348. the Virunga Massif. The fact that it has gone largely Blackburn, D.C. (2009): Diversity and evolution of male secondary unnoticed for over 79 years, despite the continued sexual characters in African squeakers and long-fingered frogs. presence of researchers in the area, likely reflects how Biological Journal of the Linnean Society 96: 553–573. difficult it is to encounter this species due to its cryptic Blackburn, D.C., Gonwouo, L.N., Ernst, R., Rödel, M-O. (2009): A new squeaker frog (Arthroleptidae: Arthroleptis) from the colouration and elusive behaviour of hiding in or under Cameroon Volcanic Line with redescriptions of Arthroleptis leaf litter. However, it may also be the result of the adolfifriederici Nieden, 1911 “1910” and A. variabilis Matschie, overall low density at which this species occurs in the 1893. Breviora, Museum of Comparative Zoology, Harvard region, an aspect of this species’ ecology that renders its University, 515: 1–22. potentially vulnerable to threats of extirpation. De Witte, G.F. (1941): Batraciens et reptiles. Exploration du Regardless of the reason behind the lack of data on this Parc National Albert. Mission G.F. de Witte (1933-1935). Bruxelles 33: v + 261p. species, our finding has two important consequences. IUCN SSC Amphibian Specialist Group (2014). Arthroleptis Firstly, it implies that we need to consider imperfect adolfifriederici. The IUCN Red List of Threatened Species, detection when assessing population status, drawing 2014: 2307-8235 e.T54364A3014681. http://dx.doi.org/10.2305/ conservation goals, or conducting related research on IUCN.UK.2014-1.RLTS.T54364A3014681.en this species (e.g., species distribution modelling, Kéry Schmidt, K. (2008): Imperfect detection and its consequences for monitoring for conservation. Community Ecology 9(2): 207– and Schmidt, 2008). Secondly, it reminds us of the 216. fact that our understanding of this species’ taxonomy, LAFREC (2018): Surveying the Gishwati-Mukura Biodiversity: ecology, biogeography, and behaviour requires Extensive study identifies the Park’s plant & Animal life. additional research. This is especially true if we are LAFREC Magazine 2018: 007. to monitor this species’ population status over time or Menegon, M., Pupin, F., Doherty-Bone, T. (2009): Amphibians relate its status to current and ongoing anthropogenic and reptiles of Nyungwe National Park: Preliminary species list. Protected Areas Biodiversity Project (PAB), Museo Tridentino pressures such as rapid habitat loss. de Scienze Naturali, Italy & Natural History Museum, London. WCS/REMA/GEF/UNDP/ORTPN. First records of Rugege forest squeaker from a national park in Rwanda since 1941 939 REMA (2015): Study to establish a list of threatened terrestrial ecosystems and species of Rwanda. Kigali, Rwanda. Roelke, C.E., Smith, E.N. (2010): Herpetofauna, Parc National des Volcans, North Province Republic of Rwanda. Check List 6(4): 525–531. van der Hoek, Y., Tuyisingize, D., Eckardt, W., Garriga, N., Derhé, M.A. (2019): Spatial variation in anuran richness, diversity, and abundance across montane wetland habitat in Volcanoes National Park, Rwanda. Ecology and Evolution 9: 4220–4230. Wake, D., Vredenburg, V.T. (2008): Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proceedings of the National Academy of Sciences 105: 11466– 11473. Accepted by Werner Conradie.