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First Recorded Introduction for the Saba Anole (Anolis sabanus) and an Overview of

Introduced Amphibians and Reptiles on St. Eustatius

Jesse, W.A.M.; Madden, Hannah; Molleman, Jasper; van Wagensveld, Tim

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IRCF Reptiles and Amphibians 2016

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Jesse, W. A. M., Madden, H., Molleman, J., & van Wagensveld, T. (2016). First Recorded Introduction for the Saba Anole (Anolis sabanus) and an Overview of Introduced Amphibians and Reptiles on St. Eustatius. IRCF Reptiles and Amphibians, 23(2), 144-146.

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IRCF REPTILES & AMPHIBIANS • 23(2):144–146 • AUG 2016

First Recorded Introduction for the Saba Anole

(Anolis sabanus) and an Overview of Introduced

Amphibians and Reptiles on St. Eustatius

Wendy A.M. Jesse1_{, Hannah Madden}2_{, Jasper Molleman}1_{, and Tim van Wagensveld}3

1_{Department of Ecological Science, Vrije Universiteit Amsterdam,}_{1081 HV Amsterdam, The Netherlands (w.a.m.jesse@vu.nl)} 2_{Ecological Professionals Foundation, Rosemary Lane, St. Eustatius, Dutch Caribbean}

3_{Stichting RAVON, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands}

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IRCF REPTILES & AMPHIBIANS • VOL15, NO 4 • DEC 2008 189 TABLE OF CONTENTS

T A B L E O F C O N T E N T S

F E A T U R E A R T I C L E S

Chasing Bullsnakes (Pituophis catenifer sayi) in Wisconsin:

On the Road to Understanding the Ecology and Conservation of the Midwest’s Giant Serpent ... Joshua M. Kapfer 190

The Shared History of Treeboas (Corallus grenadensis) and Humans on Grenada:

A Hypothetical Excursion ...Robert W. Henderson 198

R E S E A R C H A R T I C L E S

The Texas Horned Lizard in Central and Western Texas ... Emily Henry, Jason Brewer, Krista Mougey, and Gad Perry 204

The Knight Anole (Anolis equestris) in Florida

...Brian J. Camposano, Kenneth L. Krysko, Kevin M. Enge, Ellen M. Donlan, and Michael Granatosky 212

C O N S E R V A T I O N A L E R T

World’s Mammals in Crisis ... 220

More Than Mammals ... 223

The “Dow Jones Index” of Biodiversity ... 225

H U S B A N D R Y Captive Care of the Central Netted Dragon ... Shannon Plummer 226 P R O F I L E Kraig Adler: A Lifetime Promoting Herpetology ... Michael L. Treglia 234 C O M M E N T A R Y The Turtles Have Been Watching Me ... Eric Gangloff 238 B O O K R E V I E W Threatened Amphibians of the World edited by S.N. Stuart, M. Hoffmann, J.S. Chanson, N.A. Cox, R. Berridge, P. Ramani, and B.E. Young ... Robert Powell 243  CONSERVATION RESEARCH REPORTS: Summaries of Published Conservation Research Reports ... 245

 NATURAL HISTORY RESEARCH REPORTS: Summaries of Published Reports on Natural History ...247

 NEWBRIEFS ... 248

 EDITORIAL INFORMATION ... 251

 FOCUS ON CONSERVATION: A Project You Can Support ...252

Front Cover. Shannon Plummer. Totat et velleseque audant mo estibus inveliquo velique rerchil erspienimus, quos accullabo. Ilibus aut dolor apicto invere pe dolum fugiatis maionsequat eumque moditia erere nonsedis ma sectiatur ma derrovitae voluptam, as quos accullabo.

Back Cover. Michael Kern Totat et velleseque audant mo estibus inveliquo velique rerchil erspienimus, quos accullabo. Ilibus aut dolor apicto invere pe dolum fugiatis maionsequat eumque moditia erere nonsedis ma

sectia-tur ma derrovitae voluptam, as

IR

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REPTILES & AMPHIBIANS

C O N S E R V AT I O N A N D N AT U R A L H I S T O R Y

WWW.IRCF.ORG/REPTILESANDAMPHIBIANSJOURNAL

T

he Lesser Antillean island of St. Eustatius harbors two native anole species, the large Panther or Statia Bank Tree Anole (Anolis bimaculatus; maximum SVL 123 mm) and the smaller Schwartz’s or Saint Kitts Bank Bush Anole (A. schwartzi; max. SVL 53 mm). No exotic anoles had been reported for the island until a stray individual of the Saba Anole (Anolis sabanus) was discovered in the harbor of Oranjestad, St. Eustatius in April 2016, marking the first recorded introduction of the species.

The Saba Anole is a solitary anole species, endemic to the Lesser Antillean island of Saba, where it is abundant within its native range of just 13 km2_{. The species is of intermediate} size (max. SVL 69 mm) and males are easily distinguished by their striking spotted pattern (Fig. 1).

This individual was discovered next to shipping contain-ers in the St. Eustatius harbor area by a team of local and Dutch researchers. Ships are important vectors for reptile introductions (e.g., Powell et al. 2011, 2013; Helmus et al. 2014), and, because of its location, the lizard likely was a stow-away on one of the regular container shipments between Saba

and St. Eustatius (Crowley Maritime Corporation 2016).

Alternatively, the anole might have hitchhiked on a fishing boat, as local fishermen travel regularly between the islands. Other modes of introduction, such as natural dispersal or an escape or release from captivity, are highly unlikely. These lizards are rarely kept as pets, and a deep-water channel as well as 25 km of Caribbean Sea separate the two islands (Fig. 2). No other Saba Anoles have been found on St. Eustatius, so the existence of a reproductively active population is unlikely. The individual was euthanized shortly after capture. The lizard was an adult male (SVL 58 mm). Its identity was con- firmed by R. Powell from photographs (Fig. 3) and a photo-graphic voucher has been deposited in the Milwaukee Public Museum (MPM VZP 845). The specimen is currently being kept frozen on the island, although the tip of the tail was sent to Vrije Universiteit Amsterdam in the Netherlands for pos-sible future genetic analysis. St. Eustatius is unusual among inhabited Lesser Antillean islands in that during the past century, only one exotic herpeto-faunal species has established a viable population on the island. The parthenogenetic Flowerpot or Brahminy Blindsnake (Indotyphlops braminus) likely arrived on the island during the 1990s via shipments of ornamental plants originating in Florida (e.g., Powell et al. 2011, 2013). However, the time and origin of this introduction remains obscure and could date back further, as this species has a nearly cosmopolitan tropi-cal distribution. Introduced populations of Tropical House Geckos (Hemidactylus mabouia; locally called Woodslaves) and Johnstone’s Whistling Frogs (Eleutherodactylus

john-stonei) have been established since at least the 19th Century. However, stray individuals of two exotic species have been recorded in recent years. A few Red-eared Sliders (Trachemys scripta elegans) were kept in a private ornamental pool for several years (Powell et al. 2015). In 2013, a juvenile Green Iguana (Iguana iguana) was discovered in the cargo shipment of a vessel that had originated from Saba. That individual was

I N T R O D U C E D S P E C I E S

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immediately captured and euthanized. In February 2016, an adult female I. iguana was discovered in a residential area by a local resident, who alerted the St. Eustatius National Parks Foundation (STENAPA). That iguana was euthanized and preserved. Based on feedback from regional experts, the lat-ter individual probably traced its ancestry to Central America, where Green Iguanas are farmed in large numbers for the pet trade. This is a commonly introduced species that is firmly established on neighboring St. Maarten (Powell et al. 2015) and is widely introduced throughout the Lesser Antilles (e.g., Breuil 2013). Although no one claimed ownership, based on the area in which it was discovered, one likely explanation for its origin is that it was smuggled in from St. Maarten as a juvenile and released as an adult, possibly due to its large size. Green Iguanas are of particular concern because an estab-lished population or just a few individuals could compete or even hybridize with the critically endangered endemic popula-tion of Lesser Antillean Iguanas (Iguana delicatissima), as has happened elsewhere in the Lesser Antilles (e.g., Breuil 2013). At the very least, the presence of exotic Green Iguanas could confound conservation efforts focused on the superficially similar native iguanas. In sharp contrast, the arrival of a single Saba Anole is unlikely to have any deleterious consequences, although ongoing educational efforts and careful monitoring by resident naturalists, STENAPA staff, and volunteers are required to prevent the successful introduction of additional exotic species on St. Eustatius. Acknowledgements

We are grateful to the Academy Ecology Fund and The Netherlands Organization for Scientific Research for their financial support, which facilitated travel to the island of St. Eustatius and this successful collaboration between researchers. Literature Cited Breuil, M. 2013. Caractérisation morphologique de l’iguane commun Iguana iguana (Lennaeus, 1758), de l’iguane des Petites Antilles Iguana delicatissima

Laurenti, 1768 et leurs hybrides. Bulletin de la Société Herpétologique de France 147: 309–346. Crowley Maritime Corporation. 2016. Our Services > Shipping and Logistics > Route Details and Sailing Schedules > View Schedule of US Virgin Islands and Eastern Caribbean > View the Sailing Schedule on http://www.crowley. com/content/view/VoyageSchedule/14766. IRCF REPTILES & AMPHIBIANS • 23(2):144–146 • AUG 2016 JESSE ET AL.

Fig. 2. Map of Saba and St. Eustatius; the probable point of introduction for the Saba Anole (Anolis sabanus) described herein is marked with the red dot.

Regional map: © 2016 Google, Map data, sources: SIO, NOAA, U.S. Navy, NGA, GEBCO, Landsat. Zoomed map: ESRI World imagery, sources: Esri, DigitalGlobe, Earthstar Geographics, CNES/Airbus DS, GeoEye, USDA FSA, USGS, Getmapping, Aerogrid, IGN, IGP, and the GIS User Community.

Fig. 3. The adult male Saba Anole (Anolis sabanus) captured on St.

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146 IRCF REPTILES & AMPHIBIANS • 23(2):144–146 • AUG 2016 JESSE ET AL. Helmus, M.R., D.L. Mahler, and J.B. Losos. 2014. Island biogeography of the Anthropocene. Nature 513: 543–546. Powell, R., R.W. Henderson, M.C. Farmer, M. Breuil, A.C. Echternacht, G. van Buurt, C.M. Romagosa, and G. Perry. 2011. Introduced amphibians and reptiles in the Greater Caribbean: Patterns and conservation implications, pp. 63–143. In: A. Hailey, B.S. Wilson, and J.A. Horrocks (eds.), Conservation of

Caribbean Island Herpetofaunas. Volume 1: Conservation Biology and the Wider Caribbean. Brill, Leiden, The Netherlands.

Powell, R., R.W. Henderson, G. Perry, M. Breuil, and C.M. Romagosa. 2013.

Introduced amphibians and reptiles in the Lesser Antilles, pp. 74–107. In: J.-L. Vernier and M. Burac (eds.), Biodiversité insulaire: la flore, la faune et

l’homme dans les Petites Antilles. Actes du Colloque international, Schoelcher,

8–10 Novembre 2010. Direction de l’Environment, de l’Aménagement et du Logement de Martinique and Université de Antilles et de la Guyana, Schoelcher, Martinique.

Powell, R., R.W. Henderson, and J.S. Parmerlee, Jr. 2015. The Reptiles and

Amphibians of the Dutch Caribbean: Saba, St. Eustatius, and St. Maarten. 2nd