Three photographic surveys were conducted during the period; 2010 to 2011, 2013 and 2014, and supplemented by physical sampling for a one-week period in January 2015, in a wide variety of habitats on the island of St. Eustatius, West Indies, for the presence of spiders. Seventeen localities were surveyed from 15 habitats, including ve man-made habitats. Twenty-four families representing 53 species were collected. Members of the family Araneidae comprised almost a quarter of the species found. More species in natural than in human-made or highly disturbed habitats.
Globally, arachnids are considered to be one of the less documented classes of animals on our planet. Worldwide distribution comprises all land environments except polar extremes. There are currently 40,700 described species of spider, considered to represent only one fifth of the true total (Plantnick, 2009). On a faunistic level, arachnids in some regions are considered to be reasonably well known. However this is not the case for the Caribbean with only 8 islands having species level surveys for spiders. These include Cuba (Alayón, 1995), Barbados (Bryant, 1923; Alayón & Horrocks, 2004), St. Vincent & the Grenadines (Simon, 1894; de Silva, Horrocks & Alayón, 2006), Anguilla (Sewlal & Starr, 2006), Nevis (Sewlal & Starr, 2007), St. Kitts (Sewlal, 2008) and Grenada (Sewlal, 2009a), and a family level list for Trinidad (Cutler, 2005, Sewlal & Cutler, 2003, Sewlal & Alayón, 2007, Sewlal, 2009b). Other orders within the class Arachnid appear to be even less documented.
The St Eustatius National Parks Foundation (STENAPA) is actively protecting the national parks and protected areas of the island. In order to do this it is vital to provide biological inventories which represent the biodiversity of the park and therefore provide a basis on what should be protected. A lack of knowledge of the arachnid taxa has lead to a preliminary survey which has resulted in discovering 7 arachnid orders present on the island and twenty families of spider.
The fundamental aim of the project was to survey the arachnid fauna of St Eustatius and collect and document a substantial part of the total species present in a broad range of habitats. Therefore,
- A greater knowledge of the biodiversity of the island will be achieved
- A further contribution to the present data of arachnids, on both local and global scales will be achieved.
In order to accomplish these goals a wide variety of habitats will be surveyed for the presence of arachnids. The aim is to sample as many different locations as possible to determine species richness in both natural and man made habitats.
St. Eustatius lies in the northern Leeward Islands portion of the West Indies, southeast of the Virgin Islands and immediately to the northwest of Saint Kitts and Nevis, at 17°30′N 62°58′W / 17.5°N 62.967°W. In geographical terms the island is a saddle shape, with the 602 meter high volcano named The Quill to the southeast and smaller collection of hills to the northeast, known as the Northern Hills.