Inventory

St. Maarten is one of the islands forming the inner arc of the Lesser Antilles. It is older than Saba and St. Eustatius. The oldest rock strata date from ± 50 million years ago. The island experienced periods of uplift and descent. In the Pleistocene period it formed one island together with Anguilla and St. Barths.

St. Maarten is irregular in form because of the many bays and lagoons. Steep rocky coasts alternate with sandy beaches. The major part of the island is hilly. Three ridges can be distinguished in the north-south direction. Only the Low Lands in the west are flat. In the past St. Maarten was a plantation island, with sugarcane cultivation reaching high up into the hills. Now tourism is the main economical activity. The island has two parts: The French and the Dutch part. About 38.000 people live on St. Maarten on the Dutch side, especially in the valleys, but also more and more in the hills. Because of the high population density and tourism development a lot of nature has already been lost, and several habitats are under pressure. According to the system of Köppen the climate of Maarten falls between a savanna and monsoon climate. The island is situated in the Atlantic hurricane zone. In September 1995 St. Maarten was hit by a severe hurricane.

At least 522 wild plants are known from St. Maarten, divided in 506 seed plants and 16 ferns. Among the plants there are two island-endemic species: Calyptranthes boldinghgii en Galactia nummelaria. Both species are very rare or have possibly disappeared already. The geographical distribution of five plants is limited to just a few islands and 3.3% of the species is endemic to the Lesser Antilles and the Virgin Islands. With respect to the moss flora, only two true mosses are known, and no liverworts.

The major part of the Dutch side of St. Maarten is covered with secondary vegetation derived from either seasonal formations or dry evergreen formations. Only on the top of the hills some more or less original semi-evergreen seasonal forest is found. This type of forest has regionally become extremely rare too. Locally it includes several species that are lacking elsewhere in the island. Because of its small area this forest formation is very vulnerable. On the higher hills of the two ridges in the middle part of the island, and on the hills of the eastern ridge, a dense secondary woodland vegetation is growing, preventing erosion and with a high scenic value. Along the coast and inland waterways remains of mangrove forests and other types of coastal vegetation survive, which are of high ecological value, and also have scenic value.

The fauna of St. Maarten is poor in species, not only because of St. Maarten’s small size, but also because of habitat destruction, hunting, imported predators and hurricanes. One bird species, the Red-tailed Hawk, Buteo jamaicensis, and two kinds of reptiles, the Antillean Iguana Iguana delicatissima and the original population of the Green Iguana, Iguana iguana, have already been exterminated. Among the vertebrates, birds form the largest group. Especially the number of migrating birds and visitors is big. In total there are 39 resident and nesting birds on St. Maarten and 68 species of migrating birds and visitors have been observed. These include 19 sea birds, of which 10 species breed in or in the vicinity of the island. St. Maarten is classified as an important breeding area for seabirds. Several small rocky islands just off shore accommodate breeding colonies of seabirds. 2 Amphibians and reptiles are the next largest group of vertebrates. They are represented by 15 species. Bats are probably the only native mammals. There are six species on St. Maarten.

The subspecies of the tree lizard Anolis wattsi pogus can be regarded as an island-endemic species. The animal is extinct in other islands. Several vertebrates are endemic for the Lesser Antilles and the Virgin Islands, either at the species level or the subspecies level: one bat, one amphibian and six reptiles. The ground lizard Ameiva pleei, the tree lizard Anolis gingivinus, the gecko Sphaerodactylus sputator, the Grass-snake Alsophis rijersmai and the subspecies of the gecko Sphaerodactylus macrolepis parvus are limited to only a few islands. The White crowned Pigeon Columba leucocephala and the Red-Necked Pigeon Columba squamosa, both regionally and locally rare because of hunting, are still found in the island and could increase because of the diminished pressure of hunting. Among the breeding seabirds three, Audubon’s Shearwater Puffinus lherminieri lherminieri, the Brown Pelican Pelecanus occidentalis occcidentalis, and the Roseate Tern Sterna dougallii dougallii, are endangered and three, the Red-billed Tropicbird Phaeton aethereus mesonauta, the Sooty Tern Sterna fuscata fuscata, and the Least Tern Sterna albifrons antillarum, are possibly endangered. Of the invertebrates not much more is known than 170 names.

The main threats to the biodiversity of St. Maarten are habitat destruction and degradation caused by the growth of inhabited areas, tourism development and pollution. Since the fifties several people argued for the need to preserve valuable nature areas, not only for ecological motives, but also for the benefit of tourism. Stinapa-St. Maarten, the later St. Maarten National Heritage Foundation, and Stinapa Netherlands Antilles, have struggled continuously to establish a hilltop protected area and a nature/culture reserve Belvédère/Bishophill. Their aim should be supported. At present the necesary island legislation is being worked on. For effective nature management in St. Maarten complete floristic surveys are necessary, and further studies of the status of the island populations of regionally and locally scarce and/or endangered species. For now, a few conclusions can be drawn regarding the conservation of biodiversity on St. Maarten. For this conservation it is necessary to safeguard the largest possible contiguous areas of nature. To this aim the following areas are recommended for conservation and management: the ‘Hillsides’, Naked Boy Hill and surroundings, and the hills and coastal area between Guana Bay en Back Bay. For the benefit of the bats the top of Billy Folly is recommended, and for the avifauna the various ponds, coastal habitats and the little islands Pelican key, Molly Beday and Hen and Chickens.

Abstract:

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. 

Abstract:

Saba is the smallest of the three Windward Islands in the Netherlands Antilles, with an area of 13 km2. Saba is the northernmost island within the Lesser Antilles' inner curve. The island is actually the top of a dormant volcano. Typical of the island are the steep cliffs, deep ravines running radially and sheer cliff coasts. The highest top is the Mt. Scenery, commonly called “The Mountain”. About 1200 people live on Saba in four villages all situated on the south- eastern half of the island. The northwestern half is not inhabited. Only a small part of the land area is used for agriculture or cattle breeding. In the south there is a stone crusher facility.

The climate is tropical and according to the system of Köppen it falls between a savanna- and monsoon climate, however the big differences in altitude cause a large variety of climatologi- cal conditions. Above 450 meters the rainfall and humidity gradually increase until they reach their maximum on the top of The Mountain. The top of The Mountain is nearly always veiled in clouds. The diversity of plants and plant-communities is caused by these variations in climatological conditions.

With 520 species the small island of Saba possesses practically the same number of species of wild plants as the much larger island of St. Maarten. The number of ferns is especially large. Saba has no island-endemic species among the plants. However, the geographical distribution of six species and one variety is limited to only a few islands, and 4.6% of the species is en- demic to the Lesser Antilles and the Virgin Islands. The Bryophyte flora consists of 48 leaf mosses and 31 liverwort species.

Expressing the differences in climatological conditions as the altitude increases, a series of plant communities are found, ranging from Croton thickets to (secondary) rainforest and elfin woodland. The elfin woodland is of a regionally rare type. The palm brakes and the ravine rainforest are practically undisturbed by human activities. They belong to the few virgin vegetations of the Netherlands Antilles. The tree-fern brakes are a special type of secondary vegetation, which develops under conditions of high humidity. The secondary rainforest zone was seriously disturbed in the past. There are still small cultivation plots here. Wherever the vegetation is left alone however, new rainforest is developing. The rainforest is one of the most species-rich plant communities. This is also where the greatest number of leaf mosses are found on Saba. The evergreen and seasonal formation zones were also disturbed in the past, however the vegetation is recovering. The great variety of forest formations on The Mountain makes this area highly attractive to visitors. The uninhabited area in the northwest of the island is important to the survival of various small island populations and has a high scenic value.

Saba's fauna has very few species compared to a similar area on the mainland, but this is to be expected from a relatively isolated small island.
Among the vertebrates the birds form the largest group, represented by 26 local and breeding species. In addition 36 migrating species are present every year on a temporary basis. Amphibians and reptiles are the next largest group of vertebrates with eleven species.

Bats are the only mammals on Saba that were not introduced by humans. This group is represented by five species. There is one island endemic among the vertebrates: the lizard Anolis sabanus. One species, the Red-bellied Racer Alsophis rufiventris is limited to Saba and St. Eustatius and is listed on the “Red List of Threatened Animals” of the IUCN. Various vertebrates are endemic to the Lesser Antilles and the Virgin Islands, either at the species level or the subspecies level: two bats, nine birds, one amphibian and one reptile. The gecko Sphaerodactylus sabanus, the bat sub-species Natalus stramineus stramineus and the Trembler Cinclocerthia ruficauda pavida have a geographical range, which is limited to only a few islands. Among the birds and reptiles there are species of which the population has declined because of hunting or the gathering of the eggs, like for instance the Rednecked Pigeon Columba squamosa, the Audubon's Shearwater Puffinus lherminieri, and the green Iguana Iguana iguana. A few bird species are regionally almost completely limited to the habitat of the rainforest and the mountain formations, e.g. the Purple-throated Carib Eulampis jugularis, the Trembler Cinclocerthia ruficauda pavida and the Blue-crowned Euphonia Euphonia musica flavifrons, which has not been seen since 1952. The possibly endangered Bridled Quail-dove Geotrygon mystacea and Red-billed Tropicbird Phaeton aetherius mesonauta breed on Saba. Of the latter the breeding population on Saba is the largest of the Caribbean region. Of the invertebrates not much more is known than 86 names. The Mountain Crab Gecarcinus ruricola is endangered through hunting.

In the past the nature of Saba was mainly impacted by activities related to agriculture and cattle breeding. Today, the most important threats are destruction and degradation of habitat by development in general, especially because of the lack of regulations.
Since the nineteenfifties there is a lot of interest in the conservation of nature and the beautiful scenery. The necessity to preserve the top of The Mountain is mentioned many times, accompanied by specific plans. A group of people even promoted the idea to declare the whole island of Saba a conservation park. Up until today however, the terrestrial nature on the island remains unprotected.

Several studies have produced a wealth of data, yet not enough for optimum nature conservation. Further vegetation research of the top of The Mountain and the northern part of the island is necessary, as well as further study of the status of the island populations of regionally rare and/or endangered species. Also additional knowledge of the invertebrates is needed.

For now a few general conclusions can be drawn with respect to conservation of the biodiversity. For this conservation it is necessary to secure large contiguous areas. For small islands this can be problematic, but there are still a lot of possibilities on Saba. In particular the uninhabited northwestern part of the island and The Mountain above 450 meters would qualify. Specific conservation is required for the breeding places of the Audubon's Shearwater, Tropicbirds and other seabirds on Green Island and Diamond Rock.