Herpetology Notes, volume 12: 877-880 (2019) (published online on 14 August 2019)

Unsuccessful introduction: first records of Rana arvalis Nilsson, 1842 and Pelophylax ridibundus (Pallas, 1771) from the island of Norderney, East Frisian Islands, Lower Saxony, Germany

Sven Mecke1,*, Felix Mader2, Lisa Bleß3, Max Kieckbusch4, and Raffael Ernst5

The East Frisian Islands, a chain of islands in the not exist, as no vouchers are available to verify records North Sea off the coast of Lower Saxony, Germany, (Podloucky, 2008). were naturally free of amphibians, with the natterjack Another ranid species, the marsh frog, Pelophylax toad, Epidalea calamita (Laurenti, 1768), potentially ridibundus (Pallas, 1771) complex – the largest member an exception (Mohr, 1926). However, during the first of the green frog group – was introduced to Juist half of the 20th century, at least eleven amphibian (Leege, 1935) but did not persist. Green frogs have also species had been accidentally or deliberately introduced been recorded from Borkum (Bitz, in litt. 1981, cited in to various localities (see Fig. 1 herein). Attempts to Podloucky, 2008) and Wangerooge (Bach, in litt. 1983, naturalize amphibians on these islands usually proved cited in Raker, 1984) during the 1980s, but no species unsuccessful, since small freshwater pools are often names were assigned. Despite being the second largest only temporarily available (Podloucky, 2008). island of the East Frisian Islands, both moor and marsh The moor frog, Rana arvalis Nilsson, 1842, was frogs have never previously been recorded from the naturalized on Spiekeroog in 1915 (the earliest island of Norderney. introduction of this species to the East Frisian Islands During a systematic survey and digitization of hitherto reported; but see below), where it may have the collection of the well-known zoologist and occurred up until the 1970s (Leege, 1935, 1962; parasitologist Karl Georg Friedrich Rudolf Leuckart Dircksen, 1963; Meyer-Deepen and Meijering, 1979). (1822–1898) housed at the Museum of Zoology, Consecutive yet unsuccessful attempts to introduce Senckenberg Natural History Collections Dresden (see moor frogs to the island of Juist were made until 1932 Mecke et al., 2016), we recovered two historic jars, (Leege, 1935; Lemmel and Smit, 1981). Accounts one containing a single ethanol-preserved specimen of from other East Frisian Islands (Baltrum, Borkum, an adult moor frog# (MTKD 7876, original collection Langeoog) are regarded doubtful and are likely based on number Coll. Leipzig Nr. 334, Prof. Leuckart leg. VII misidentification and confusion with the similar looking 1873) and the other one a marsh frog## (MTKD 7972, no Rana temporaria Linnaeus, 1758 (Podloucky, 1987, original number, Prof. Leuckart leg. VI 1873) (Fig. 2). 2008). Reliable records from the island of Memmert do According to the original catalogue entry and voucher

1 Naturkundemuseum Paderborn, Im Schloßpark 9, 33104 Paderborn, Germany. # This specimen was identified as Rana arvalis based on the fol- 2 Bachgasse 1, 93083 Obertraubling, Germany. lowing characters: callus internus very large and hard, shorter 3 AG Spezielle Zoologie und Evolution der Tiere, Fachbereich than the first toe by 1.2 times; length of hind leg (from body Biologie, Philipps-Universität Marburg, Karl-von-Frisch- wall to tibio-tarsal articulation) equals distance from cloaca to Straße 8, 35032 Marburg, Germany. eye; head as long as broad; belly unspotted. 4 Malmedystraße 7, 81379 München, Germany. ## This specimen was identified as Pelophylax ridibundus based 5 Sektion Herpetologie, Museum für Tierkunde, Senckenberg on the following characters: callus internus small, very flat Naturhistorische Sammlungen Dresden, Königsbrücker and triangular, typical for P. ridibundus specimens from Landstraße 159, 01109 Dresden, Germany. northern Germany (fide Nettmann, in litt.); ratio of first toe * Corresponding author. E-mail: [email protected] length/length of callus internus > 2.6; tympanum dark grey. 878 Sven Mecke et al.

Figure 1. Distribution of amphibians in the East Frisian Islands, Lower Saxony, Germany. Numbers on the map correspond to species numbers above. Records are from Podloucky (2008) and this study (first records for Norderney). † = extinct, †? = likely extinct, ? = doubtful record(s) or status unknown. Photos by Sven Mecke (1–4, 6–8, 11 & 12), Kai Kolodziej (5), and Andres Meyer (9 & 10). Map prepared by Max Kieckbusch.

labels, both specimens were collected on the island of (by > 40 years). Their introduction to Norderney Norderney by Leuckart as early as 1873 (only 31 years coincides with a period of extensive infrastructural after the formal description of Rana arvalis by Nilsson activities on this island that took place between 1858 in 1842). These are the first records of R. arvalis and and 1875 and included the construction of (1) a dyke of Pelophylax ridibundus for Norderney, demonstrating in 1858 following the severe storm tide of 1855, (2) the that the introduction of these ranids to the East Frisian harbour area from 1871–1890, (3) the lighthouse from Islands occurred much earlier than previously reported 1871–1874, and (4) accommodation facilities for up to First records of Rana arvalis and Pelophylax ridibundus from Norderney 879

Figure 2. Two frog specimens collected on Norderney, East Frisian Islands, Lower Saxony, Germany by Rudolf Leuckart in 1873. (A–D) Rana arvalis (MTKD 7876, original collection number Coll. Leipzig Nr. 334), in (A) dorsal, (B) ventral, and (C) lateral views. (D) Hind feet of the specimen, with arrow pointing to the very large and hard callus internus that is 1.2 times shorter than the first toe. (E–H) Pelophylax ridibundus (MTKD 7972, no original number) in (E) dorsal, (F) ventral, and (G) lateral views. (H) Hind foot of the specimen, with arrow pointing to the small, very flat and triangular callus internus. The depicted specimens represent the first records for the island of Norderney and the oldest for the East Frisian Islands. Photos by Raffael Ernst (A & B, D–F, H) and Sven Mecke (C, G). Scale bars = 2 cm. 880 Sven Mecke et al.

2600 bathers until 1865 (Behre and van Lengen, 1995; Leege, O. (1962): Lebensgemeinschaften auf werdendem Land in Stuhr, 2011; Fründt, 2015; Dehne, 2018). The lack of der Nordsee. Tier und Umwelt 3: 1–25. more recent records indicates that both moor and marsh Lemmel, G., Smit, C.J. (1981): Distribution, ecology and zoogeography of amphibians and reptiles in the Wadden Sea frogs probably disappeared from Norderney shortly area. In: Terrestrial and Freshwater Fauna of the Wadden Sea after their introduction, the exact date of which remains Area, p. 159–169. Smit, C.J., Hollander, J. den, Wingerden, unknown. W.K.R.E. van, Wolff, W.J., Eds., London, United Kingdom, This unexpected discovery once more emphasizes Routledge. that natural history collections are important archives Mecke, S., Mader, F., Kieckbusch, M., Kaiser, H., Böhme, W., and data bases that provide crucial information about Ernst, R. (2016): Tracking a syntype of the Australian skink historic occurrences and distributions of taxa; they Anomalopus leuckartii (Weinland, 1862): ‘lost’ treasures in the Senckenberg Natural History Collections Dresden highlight can even inform about human-driven alterations in the the importance of reassessing and safeguarding natural history patterns of past and present species distributions. collections. Vertebrate Zoology 66 (2): 169–177. Meyer-Deepen, J., Meijering, M.P.D. (1979): Spiekeroog – Acknowledgements. We thank Kai Kolodziej (University Naturkunde einer ostfriesischen Insel. Spiekeroog, Germany, of Vienna, Austria) and Andres Meyer (karch, Neuchâtel, Kurverwaltung Nordseebad Spiekeroog. Switzerland) for providing photographs shown in Fig. 1, and Mohr, E. (1926): Die Lurche und Kriechtiere Schleswig-Holsteins. Richard Podloucky for supplying some of the references. Nordelbingen – Beiträge zur Heimatforschung in Schleswig- Wolfgang Böhme (Zoologisches Forschungsinstitut und Museum Holstein 5 (2): 1–50. Alexander Koenig, Bonn, Germany) provided a pre-review of this Podloucky, R. (1987): Zur Verbreitung und Bestandssituation note. We are also very grateful to Hinrich Kaiser (Victor Valley des Moorfrosches (Rana arvalis Nilsson) in Niedersachsen. College, Victorville, USA) and Hakon Nettmann (University Schriftenreihe Naturschutz und Landschaftspflege in of Bremen, Germany) for useful comments on the manuscript. Niedersachsen, Beiheft 19: 15–57. The collection work upon which this publication is based was Podloucky, R. (2008): Lurche und Kriechtiere. In: Die Flora und supported by a grant from the Paul Ungerer-Stiftung to RE and Fauna der Ostfriesischen Inseln – Artenverzeichnisse und SM. Auswertung zur Biodiversität. In: Die Flora und Fauna der Ostfriesischen Inseln, p. 411–420. Niedringhaus, R., Haeseler, References V., Janiesch, P., Eds., Oldenburg, Germany, Nationalpark Wattenmeer. Behre, K.-E., van Lengen, H. (1995): Ostfriesland: Geschichte und Raker, M. (1984): Zwischenbericht über die Situation der Gestalt einer Kulturlandschaft. Aurich, Germany, Ostfriesische Kleingewässer auf der Insel Wangerooge unter besonderer Landschaft/ Niedersächsisches Institut für Historische Berücksichtigung ihrer Amphibien. Unpublished report on the Küstenforschung. occasion of the JRK-nature conservation project on Wangerooge, Dehne, G. (2018): Die Nordseeinsel Norderney: Die Vielfalt einer Geseke, Germany. Insel entdecken. Norderstedt, Germany, Books on Demand. Stuhr, K.-H. (2011): Norderney. Ein historischer Streifzug. Erfurt, Dircksen, M. (1963): Die grüne Insel Spiekeroog. Herford, Germany, Sutton Verlag. Germany, Maximilian-Verlag. Fründt, H.-J. (2015): InselTrip Norderney. Bielefeld, Germany, Reise Know-How Verlag. Leege, O. (1935): Werdendes Land in der Nordsee. Schriften des Deutschen Naturkundevereins, Neue Folge 2. Oehringen, Germany, Verlag Hohenlohe’sche Buchhandlung Ferdinand Rau.

Accepted by Hinrich Kaiser