Saba’s endemic iguana species recognized

Saba’s black melanistic iguana has been recognized as an endemic species. Although Sabans have a somewhat ambivalent relationship with their local ‘dragon’ which is known to ravage carefully tended veggie gardens, it arguably has been on the island long before humans and thus can claim its indigenous right of peaceful coexistence.

This has been emphasized by a new study published in the ZooKeys journal by Michel Breuil, David Schikorski, Barbara Vuillaume, Ulrike Krauss, Matthew N. Morton, Elizabeth Corry, Nicolas Bech, Mišel Jelić and Frédéric Grandjean, that investigated differences between iguana species. As one of the results, the painted black (Iguana melanoderma), locally known as Saba Black Iguana, is now officially considered a separate species, endemic to Saba and Montserrat.

The recognition of the endemic iguana species will undoubtedly contribute to Saba’s distinction as a nature, eco-tourism destination, but at the same time scientists are warning that the melanistic black iguana is under threat. Threats include unsustainable harvesting, including pet trade, and both competition and hybridization from escaped or released invasive alien iguanas from South and Central America.

The international research group, of which some members visited Saba in 2012 to do DNA sampling, has called for urgent conservation measures in a scientific article titled “A new species of black endemic iguanas in Caribbeans is proposed for urgent conservation,” recently published in the open-access journal ZooKeys.

Three species

So far, there are three species of iguana known in this area of the Caribbean. The Lesser Antillean iguana (Iguana delicatissima), an endemic species found in very few islands, including St. Eustatius, is highly endangered. Two introduced species of iguanas are found on the islands: the common iguana (Iguana iguana iguana) from South America and the green iguana (Iguana rhinolopha) from Central America. Both are threatening the endemic iguana species.

The described species on Saba and Montserrat is characterized with private micro-satellite alleles, unique mitochondrial ND4 haplotypes and a distinctive black spot between the eye and the ear cavity. Juveniles and young adults have a dorsal carpet pattern, the coloration is darkening with aging, except for the anterior part of the snout.

Scientists describe the common melanistic iguanas from Saba and Montserrat as a new taxon and aim to establish its relationships with other green iguanas. That can help conservationists to accurately differentiate this endemic lineage from invasive iguanas and investigate its ecology and biology population on these two small islands that are subject to a range of environmental disturbances including hurricanes, earthquakes and volcanic eruptions.

Conservation

“Priority actions for the conservation of the species Iguana melanoderma are biosecurity, minimization of hunting, and habitat conservation. The maritime and airport authorities of both islands must be vigilant about the movements of iguanas, or their sub-products, in either direction, even if the animals remain within the same territory. Capacity-building and awareness-raising should strengthen the islands’ biosecurity system and could enhance pride in this flagship species,” stated lead researcher prof. Frédéric Grandjean of the University of Poitiers, France.

The group of scientists were not the first to point out the importance of protecting the Saba iguanas. Initial efforts already started with Robert Powell who authored the book “The Reptiles and Amphibians of the Dutch Caribbean,” together with two other authors, Robert W. Henderson and John S. Parmerlee, Jr. In 2017, the Saba Conservation Foundation (SCF) erected signs around the island to raise awareness about Saba iguanas on the road.

The key stakeholders in conservation efforts for the area are the SCF, Dutch Caribbean Nature Alliance (DCNA), the Montserrat National Trust (MNT) and the UK Overseas Territories Conservation Forum (UKOTCF), which, the research team hope, could take measures in order to protect the flagship insular iguana species, mainly against alien iguanas.

SCF