By Suzanne Koelega
LEIDEN/ORANJESTAD–Researchers found at least eighty animal and plant species that are new to St. Eustatius during a two-week expedition to the island earlier this month. Among the discoveries were beetles, flies, bees, snails, birds, bats which will all be added to Statia’s species list.
The majority of the species are found in other parts of the Caribbean, but had not been officially listed for St. Eustatius. However, the researchers from the Natural Biodiversity Centre in Leiden, the Netherlands and several other organisations are not excluding the possibility that some species are entirely new to the Caribbean or even to science.
An inter-disciplinary team of 28 researchers, seven students of the Leiden University and two local park rangers of the St. Eustatius National Parks Foundation STENAPA researched and mapped Statia’s biodiversity during the two-week expedition from October 2 to 18.
All species encountered in 11 pre-selected testing areas of 25 by 25 metres in various vegetation types were studied, whereby different techniques were used. Birds and reptiles were counted, vascular plants and mosses collected, mammals were captured with automatic camera systems, insects were caught with nets, and snails and beetles sifted from the soil. Species and data were also collected outside of the testing areas.
The researchers were especially proud of the discovery of the Lesser Antilles long-tongued bat, the Statia bee and the Caribbean silver-body fly which might even be new to science. Three bird species were added to Statia’s bird list, including the Solitary Sandpiper and the Semi-palmated Sandpiper. These are birds that use the island as a stop-over in their migration between North and South America and which had never been formally registered on the island.
The testing areas were based on coordinates randomly selected by a computer and were sometimes located in very hard to reach places like White Wall with its very steep slope. Some of the areas were located in the crater and on the rims of The Quill. Sometimes machetes and ropes had to be used. The teams worked at all hours of the day and night. Some researchers even spent a night in hammocks in The Quill.
“We used different kinds of traps to catch insects. We dug in cups to catch beetles and put out yellow cups which some insects see as a large flower. We put water and soap in the yellow cups,” said expedition leader Berry van der Hoorn of the Naturalis Biodiversity Centre.
“We took two from each species. We only looked at mammals, birds, iguanas and snakes. You need to collect insects and other small animals because they are hard to study and identify in the field due to their small size,” said Van der Hoorn who used the term “impressive” to describe the two-week mission for which on-island preparations started in March this year.
“For us it was genuine fieldwork and it gave us the opportunity to get to know St. Eustatius and its people,” he told The Daily Herald. Even though a lot of species have disappeared over the years, as have in many islands throughout the world, there is still much to discover in St. Eustatius, said Van der Hoorn. “We discovered new species at every testing site.” He said that it was a lot for a rather small island.
The research will lead to a vast expansion in knowhow of Statia’s nature. “Until now the information was quite scattered. It was never thoroughly analysed by a multi-disciplinary team of this kind.”
According to Van der Hoorn, traditionally there was much more knowledge of former Dutch colonies, like Suriname and Indonesia than of the Dutch Caribbean. He said that the last time animal species were collected on the islands dated back to the 1940’s.
“We don’t have enough knowledge of the biodiversity of this part of the Netherlands,” he said about St. Eustatius, a Dutch public entity since October 2010. “We are going to change that, because if you don’t know what’s there, you cannot protect it.” Van der Hoorn said the idea was to create a species list for St. Eustatius which will become part of the Dutch Caribbean Species Catalogue.
Van der Hoorn was especially thankful for the assistance of STENAPA rangers Ambrosius, Chuck and park manager Hannah Madden. “They have a wealth of knowledge of local species and that helped us a lot.”
The presence of the Caribbean Netherlands Science Institute (CNSI) on the island proved a very valuable asset, in fact, it was one of the reasons why St. Eustatius was selected for the expedition, said Van der Hoorn. “We were well facilitated by the CNSI. We made good use of the labs and working areas. Plus it provided good, not too expensive accommodation for the students.”
Many of the species that were collected need further research at Naturalis. The collected samples, which include insects and invertebrates from the 250 traps in the testing areas, were brought to the Netherlands last week for further analysis. DNA techniques will be used for this analyses which is expected to increase the number of 80 new species that were found. “This work will take us another year,” said Van der Hoorn.
The objective of the expedition was two-folded: researchers wanted to give an impulse to the island’s general species records which hadn’t been intensively analysed as yet, while at the same time study the coherence between the various sorts.
For example, whether the areas with the largest birds diversity are also the areas with the biggest diversity of plants or insects. “In order to research this, you need marked-off eco-systems. An island is perfect for this,” said Van der Hoorn, who added that the information would help to protect the local nature.
The expedition to St. Eustatius is cooperation between Naturalis Biodiversity Centre, St. Eustatius National Parks Foundation STENAPA, the Netherlands Mammal Society, the Netherlands RAVON foundation specialised in reptiles, amphibians and freshwater fish RAVON and the Netherlands EIS foundation specialised in insects.
Through Leiden University, Naturalis Biodiversity Centre started this year with a Caribbean programme, “Tropical Biodiversity and Field Methods.” In June a marine expert team visited St. Eustatius for three weeks to identify the species living underwater. The largest partner organisation of the marine expedition was the ANEMOON Foundation. In March 2015 a Naturalis team went to the island for a terrestrial exploratory expedition in preparation for the two-week expedition in October that year. At that time, the testing sites were inspected.
Source: The Daily Herald