lizards

Florida is a hotspot for non-native species including many reptiles, which are spreading unchecked to the Caribbean. The Peters’s Rock Agama, a lizard native to sub-Saharan Africa, is among the latest species to spread from Florida to the Caribbean islands. Conservationists are expressing their fear for the impacts of this non-native species in a public letter which advises scientists, conservationists, policy makers, veterinarians and border control agencies to be on high alert.

Florida is widely known to be a hotbed of invasive alien species, including many non-native reptiles from around the world. It is not uncommon to see new reports about green iguanas (a species from Central America) falling from the trees during cold spells, or large pythons from Asia preying on native deer and alligators in the Everglades. There are many other aliens that receive far less attention yet are no less dangerous.

Among the most insidious aliens is the Peters’s Rock Agama, or Agama picticauda, a reptile native to western and central Sub-Saharan Africa. This colorful lizard first arrived in Florida in the 1970s and has since spread across the Sunshine State, preying on a wide range of small animals.

(Peters’s Rock Agama in Florida. Photo credit: Vijay Barve)

New citizen science reports show this species has now reached the Bahamas and the British Virgin Islands, undoubtedly carried as stowaways on vessels out of Florida. A group of Caribbean-based biologists and conservationists are now expressing their deep concern because this region is a biodiversity hotpot with thousands of unique, endemic species, over 1,500 of which are already at high risk of extinction. Other undesirable aliens that are inferred to have spread to the Caribbean via Florida in recent years including Green Iguanas (Iguana iguana), Black Spiny-tailed Iguanas (Ctenosaura similis) and Asian House Geckos (Hemidactylus frenatus).

(Peters’s Rock Agama in Florida. Photo credit: John Wolaver)

In their letter to the journal Animal Conservation, co-authored by Dolfi Debrot from Wageningen Marine Research, the authors identify nearly 50 native reptile species that could be impacted if the agama becomes established across the Eastern Caribbean. Many species are at risk of being eaten by the agamas and even large native lizards are likely to experience competition and displacement given the agama’s aggressive behaviours.

The authors advise scientists, conservationists, policy makers, veterinarians and border control agencies to be on high alert for incursions by Peters’s Rock Agamas and other non-native reptiles. They further urge the transport sector – especially those operating out of Florida – to be on the lookout for the agama and to take swift measures to remove them.

The letter has been published in Animal Conservation: M.P. van den Burg et al.: The threat of Peters’s Rock Agama (Agama picticauda) to reptile diversity across the Lesser Antilles. Animal Conservation 2023, 12889.

DCNA

The Dutch Caribbean Nature Alliance (DCNA) supports science communication and outreach in the Dutch Caribbean region by making nature related scientific information more widely available through amongst others the Dutch Caribbean Biodiversity Database, DCNA’s news platform BioNews and through the press. This article is part of a series of articles on ‘Invasive Alien Species in the Dutch Caribbean”. This article contains the results from several scientific studies but the studies themselves are not DCNA studies. No rights can be derived from the content. DCNA is not liable for the content and the in(direct) impacts resulting from publishing this article.

Florida is een hotspot voor uitheemse soorten, waaronder veel reptielen, die zich via de transport van goederen ongecontroleerd verspreiden naar het Caribisch gebied. De Peters’s rock agame, een hagedis die oorspronkelijk uit Afrika komt, is een van de laatste soorten die zich van Florida naar de Caribische eilanden aan het verspreiden is. Natuurbeschermers uiten hun zorg voor de gevolgen hiervan.

Florida staat algemeen bekend als een broeinest van invasieve uitheemse soorten, waaronder veel uitheemse reptielen van over de hele wereld. Het is niet ongewoon om verhalen te horen over groene leguanen – een soort uit Centraal-Amerika – die er bij kou uit de bomen vallen, of grote pythons uit Azië die azen op inheemse herten en alligators in de moerassen van de Everglades. Er zijn ook veel andere uitheemse soorten die veel minder aandacht krijgen, maar daarom niet minder schadelijk zijn.

(Peters’s Rock Agama in Florida. Photo credit: Vijay Barve)

Een van de meest verraderlijke ‘vreemdelingen’ is de Peters’s rock agame – of Agama picticauda – een reptiel dat oorspronkelijk uit West- en Centraal Afrika ten zuiden van de Sahara komt. Deze kleurrijke hagedis arriveerde voor het eerst in Florida in de jaren 70 en heeft zich sindsdien verspreid over de Sunshine State, waar hij aast op een breed scala aan kleine dieren.

Uit recente citizen science observaties blijkt dat deze soort nu de Bahama’s en de Britse Maagdeneilanden heeft bereikt. Hoogstwaarschijnlijk is de soort als verstekeling meegevoerd op schepen uit Florida. Een groep biologen en natuurbeschermers uit het Caribisch gebied spreekt nu haar grote bezorgdheid uit omdat deze regio een hotspot van biodiversiteit is met duizenden unieke inheemse soorten, waarvan er al meer dan 1500 met uitsterven worden bedreigd. Andere ongewenste vreemdelingen die zich de afgelopen jaren via Florida naar het Caribisch gebied hebben verspreid zijn onder andere groene leguanen (Iguana iguana), zwarte leguanen (Ctenosaura similis) en Aziatische huisgekko’s (Hemidactylus frenatus).

(Peters’s Rock Agama in Florida. Photo credit: John Wolaver)

In hun brief aan het tijdschrift Animal Conservation, die mede is geschreven door Dolfi Debrot van Wageningen Marine Research, identificeren de auteurs bijna vijftig inheemse reptielensoorten die kunnen worden bedreigd als deze agame zich in het Oostelijke Caribisch gebied vestigt. Veel soorten lopen het risico te worden opgegeten door de agames en zelfs grote inheemse hagedissen zullen waarschijnlijk concurrentie ondervinden en worden verdrongen door het agressieve gedrag van de Peters’s rock agame.

De auteurs van deze brief adviseren wetenschappers, natuurbeschermers, beleidsmakers, dierenartsen en grenscontrole-instanties om zeer alert te zijn op Peters’s rock agames en andere uitheemse reptielen. Ze dringen er verder bij de transportsector op aan – vooral diegenen die vanuit Florida opereren – om op te letten  op de aanwezigheid van de agames en snel maatregelen te nemen om ze te verwijderen.

De brief The threat of Peters’s Rock Agama (Agama picticauda) to reptile diversity across the Lesser Antilles is gepubliceerd in Animal Conservation

DCNA

De Dutch Caribbean Nature Alliance (DCNA) ondersteunt wetenschapscommunicatie en outreach in de Nederlandse Caribische regio door natuurgerelateerde wetenschappelijke informatie breder beschikbaar te maken via onder andere de Dutch Caribbean Biodiversity Database, DCNA’s nieuwsplatform BioNews en via de pers. Dit artikel maakt deel uit van een serie artikelen over ‘Invasive Alien Species in the Dutch Caribbean’. Dit artikel bevat de resultaten van verschillende wetenschappelijke onderzoeken, maar de onderzoeken zelf zijn geen DCNA-onderzoeken. Aan de inhoud kunnen geen rechten worden ontleend. DCNA is niet aansprakelijk voor de inhoud en de indirecte gevolgen die voortvloeien uit het publiceren van dit artikel.

Published in BioNews 66

The native herpetofauna of the Lesser Antillean island of Saba (13 km2; 17.63°N, -63.24°W) includes one snake, Alsophis rufiventris, and four species of lizards, Anolis sabanus, Iguana melanoderma, Sphaerodactylus sabanus, and Thecadatylus rapicauda (Powell et al. 2015). Here, we report the establishment of both Gymnophthalmus underwoo-di Grant, 1958 and Indotyphlops braminus (Daudin, 1803) on the island.

While translating the Dutch version of "de Amfibieen en Reptielen van Aruba, Curaçao en Bonaire" into English, I was forced to go through the entire text one more time, line by line. Thus it was inevitable that I ended up editing the text somewhat and adding to it as well. Since an English manuscript was now available, several people who had not been consulted previously could now give their comments, which have been incorporated in the English version. Thus the English translation is not a literal transcription of the Dutch version, although the differences between both versions are relatively minor. The islands of Aruba, Curaçao and Bonaire form part of a larger archipelago of islands along the Venezuelan coast. This archipelago includes all the islands from Los Monjes in the West to La Blanquilla in the East. The herpetofauna of the islands of Aruba, Curaçao and Bonaire should be viewed from this somewhat larger perspective. For this reason there are many references to the Venezuelan islands. Faunistic zones often transcend national borders. In this respect I have followed wagenaar hummelinck who in 1940 published the first general treatise of the herperofauna of this archipelago. My field guide is in large part based on this early work of wagenaar hummelinck (†).

This field guide is certainly not intended as a taxonomic work. Most guide books use slightly different classifications, sometimes all these differences can be quite exasperating. The latest classification is not necessarily the best, and some of the newer ideas have not gained general acceptance. In this English version the sub-species Leptodeira annulata bakeri and Crotalus durissus unicolor from the Dutch edition have been upgraded to full species status, in accordance with the prevailing taxonomic trends. I have simply tried to follow what seemed "the roads most traveled" and in many cases have indicated that other classifications also exist. In doing this I have certainly developed my own preferences, often siding with the "lumpers'', sometimes with the "splitters". I fully realize however that I do not have the expertise to make these kinds of taxonomic judgments, which are better left to others. It is however important to convey to the general public the idea that taxonomy has a subjective element and that taxonomy is not a static structure, but something that can change on the basis of new evidence or new interpretations. The field guide is also intended as a review summarizing available information on the herpetofauna of these islands. Local information on customs, beliefs and origins of local names has been included. The list of literature, cites many general works but is also intended to serve as a bibliography of the herpetofauna of the islands of Aruba, Curaçao and Bonaire. The sea turtles have not been included. In 1995 I published "De Schildpadden van Curaçao en Bonaire" (The turtles of Curaçao and Bonaire). This book was primarily intended for local use, one of its primary aims was to generate support for sea turtle protection. Since many books on sea turtles in the region already exist, there is no special need to translate this book into English.

Author's note, November 2017: This guide is somewhat outdated; some scientific names have changed, new invasive species have established themselves, at least on Curaçao, and of course new literature has appeared. Actually, a new edition is needed.

Curaçao and Bonaire form part of the Netherlands Antilles, while Aruba has a “status aparte” within the Kingdom of the Netherlands. All three islands are relatively arid compared to a typical Caribbean island, with mean annual rainfall of 409-553 mm, and experience several periods of drought lasting two or more years each century. A short history of the islands is given, and protected areas are described. The laws and regulations protecting amphibians and reptiles are complex, with general laws originating from the Kingdom of the Netherlands participation in international conventions (such as CITES) together with supplemental laws of the Netherlands Antilles and individual islands. Sea turtles are generally well protected, although their nesting beaches would be vulnerable to a rise in sea level. Among the terrestrial herpetofauna, only the Aruba Island rattlesnake (Crotalus unicolor) is on the IUCN Red List, being Critically Endangered. The status of this species and others of particular interest is described. The Curaçao Island snake (Liophis triscalis) should probably be included as Vulnerable or even Endangered, though there is insufficient information at present. Iguana iguana populations on the different islands, and the Curaçao whiptail (Cnemidophorus murinus murinus) on Klein Curaçao, are distinctive and significant for conservation. An overview is given of introduced amphibians and reptiles and their possible effects on the native fauna. The arid climate of the islands may hinder the establishment of invasive species, which are often not able to survive in the bush and thus reduces their impact on native species.