habitat

Summary

Environmental Protection in the Caribbean (EPIC) Sint Maarten Foundation launched a pelican project running from November 2022 to April 2023, the Caribbean Brown Pelican being the national bird of Sint Maarten.

The objective of the project “An investigation of the state of Sint Maarten’s Brown Pelican population for improved management of the species and its habitat” is to research the status of the Caribbean Brown Pelican on Sint Maarten through monitoring and ecotoxicology analysis and to promote conservation of the pelican through awareness raising and outreach activities.

The main nesting site is Fort Amsterdam, which is a zoned area. Monitoring this location over the years has shown declining numbers, although numbers can fluctuate depending on the stage of the breeding season or annual variation.

Reasons for a decline in numbers can include habitat loss and fragmentation, pollution, disturbance, predators, and diseases.

From our observations, pollution and disturbance should be avoided to improve nesting productivity and breeding habitat of the Caribbean Brown Pelican.

The Manual for Habitat and population management of the Caribbean Brown Pelican is a guidebook intended for key stakeholders and resource managers, in order to best manage and protect this species and its habitat. Recommendations are also included. 

ABSTRACT

Catastrophic events, like hurricanes, bring lethal conditions that can have population-altering effects. The threatened Caribbean dry forest occurs in a region known for its high-intensity hurricane seasons and high species endemism, highlighting the necessity to better understand hurricane impacts as fragmentation and clearing of natural habitat continues. However, such studies remain rare, and for reptiles are mostly restricted to Anolis. Here we used single-season occupancy modeling to infer the impact of the intense 2017 Atlantic hurricane season on the critically endangered Lesser Antillean Iguana, Iguana delicatissima. We surveyed 30 transects across eight habitats on St. Eustatius during 2017-2019, which resulted in 344 individual surveys and 98 iguana observations. Analyses of abundance and site occupancy indicated both measures for 2018 and 2019 were strongly reduced compared to the pre-hurricane 2017 state. Iguanas at higher elevations were affected more profoundly, likely due to higher wind speeds, tree damage and extensive defoliation. Overall, our results indicate a decrease in population estimates (23.3-26.5%) and abundance (22-23.8%) for 2018 and 2019, and a 75% reduction in the number of opportunistic sightings of tagged iguanas between 2017-2018. As only small and isolated I. delicatissima populations remain, our study further demonstrates their vulnerability to stochastic events. Considering the frequency and intensity of hurricanes are projected to increase, our results stress the urgent need for population-increasing conservation actions in order to secure the long-term survival of I. delicatissima throughout its range.

This one-year pilot project aims to provide an insight in the ecology of Antigonon leptopus (Corallita) an invasive vine, which is overgrowing the native vegetation (Photo 1). This pilot project is just a first step in controlling the Antigonon leptopus. This research was done on a small scale and under controlled circumstances. Our ideas are just for small scale use in town but also to eradicate ‘hotspots’ to prevent further spreading especially near the National Parks. The government with STENAPA as a consultant should take further actions to continue this project and put it as a high priority. The first step was made and we hope this will contribute in containing the species and monitoring the species closely. More research on the life circle and possible natural enemies and its sensitivity for herbicides should be done in order to start a larger scale eradication campaign. The project does not stand on its own, the vine contributes in the prevention of soil erosion on the island. A full size project including replanting/reforestation with native species and renewed agricultural activities should be set up for the long term.

Objectives

• The primary research aim is to reduce and control the growth of Corallita on St. Eustatius and to prevent the species from invading the national parks. In order to achieve this, it is necessary.
• To gather information about the ecology of the species, such as its life cycle, dispersal, germination capacity, use of the species by animals etc. • To gather information about how the species will react on different potential control methods.
• Inform the local community about control methods if usable results are obtained.

Discussion and conclusion

Three weeks after the first treatment at Gallow Bay no regrowth was observed, this means the herbicide does work with smaller concentration (12.5% and 25%) on short term. After six weeks the first regrowth was observed. The tubers are still intact after the first treatment. It is not known how many times the treatment with these concentrations is needed.

In both plots of Sandy Road the plants have regrowth after 7½ weeks. Our observation on 13th January 2007 showed that a lot of Corallita was growing from the border into the plots covering the soil. The treatment did work but probably needed a second treatment if there is regrowth of 30-40cm. Further monitoring of large plots (during one year) is needed to make sure smaller concentrations will kill the plants. Tubers should de dug up and checked on viability. New plots should be selected.

This article describes molly's morphology in different sex, natural habitats, captive molly requirements, and feed. 

Short summary:

In 1963, there are three tooth carps species native to the islands: the molly (Poecilia sphenops), one-spot molly (P.vivipara), and guppy (P.reticulata). The local variety of P.sphenops in three islands had been described already in 1887 by van Lidth de Jeude as P. vandepolli (named for its collector, van de Poll). The vernacular name of the local is machuri. In the early 1960s, Constance Feltkamp and Ingvar Kristensen investigated the islands, and later they wrote the article "Ecology and morphological characters of different populations of Poecilia sphenops vandepolli." 

Growth of tourism, urbanization, agriculture and road construction generally cause loss of habitats for native species of all kinds. In late 2004, I went to the islands to see what possible impact these factors may have had on the distribution of the local molly, especially on Aruba, due to the growth of tourism there. I found mollies in Aruba at three locations: the wetlands in northwest, at Bringamosa, and Modanza, both close to Arikok National Park; in Curacao at two locations in Willemstad; and in Bonaire at Sorobon.

The Jan Thiel lagoon can be considered the most important wetland of Curaçao based on its combined value as a feeding habitat for terns. As is likely the case in general with the other saliñas of Curaçao, Jan Thiel lagoon appears to be of the greatest significance to flamingos during the dry season when the larger wetlands in Venezuela run dry. The lagoon is also an area that has historically provided conditions suitable for massive nesting by rare species of terns. Nesting by terns still occurs but on a much lesser scale and with fewer species. During the rainy season, and because of the presence of many dams which retain fresh water on the eastern half of the lagoon, the area is of persistent value to several waterbirds which showed a preference for feeding in less saline water. These include species such as ducks, sandpipers, and black-winged stilts.

The lagoon is approximately 80 ha and is surrounded by approximately 228 ha of additional scenic conservation area which contain rare tracts of native vegetation and which provide valuable habitat to many other native species such as konènchi, sloke, tapa kaminda, and warawara. The best vegetations are found on the eastern side of the lagoon, particularly the southern quadrant of the eastern half of the lagoon. This quadrant has quite rare vegetation, best described as a Haematoxylon-Coccoloba vegetation in which the dreifi shimaron is found to be abundant on volcanic soil. Such vegetation is also known from areas of Oostpunt, Malpais, and Seru Cocori. Other species remarkably abundant in the Haematoxylon-Coccoloba unit include the mata piska and the palu di pushi while the presence of scattered kibrahacha and mangel di sabana likely indicate species which were once much more abundant but which have somehow survived the intensive use of this area in the past. Rare plant species found in the area include the trees lumbra blanku (Croton niveus), kurahout (Peltophorum acutifolum), mata kombles (Schoepfia schreberi), "fuma machu" (Vitex cymosa). For the latter species, less than 20 trees are known to exist in the Dutch Antilles. 

A major limitation to the avifaunal use of the lagoon, particularly the flamingos and tern nesting is the current high level of uncontrolled recreational disturbance. Unintentional recreational disturbance can likely be greatly reduced by a combination of properly informing visitors, by planting vegetation barriers to shelter visitors from the constant sight of the birds and by partially redirecting trails.

The planned Jan Thiel-Amandelweg road is a major threat to the ecological integrity of the conservation area. The road is protected to lie directly in the two most important freshwater areas bordering the lagoon and on top of one of the four locations which support tern breeding. The mere physical presence of the road is in itself a scourge to the vegetation as is cuts through a part of the Haematoxylon-Coccoloba vegetation and lies directly on top of three (fortunately resprouting) very rare Vitex cymosa trees. If this road is ever built it will add a large source of constant disturbance (incl. traffic noise) for much of the eastern half of the lagoon (which is the principal area used by the avifauna), and a major source of littering and contaminants from vehicles. 

The abandoned landfill of Koraal Specht has not been sealed to prevent rainwater percolation and several seeps were seen to emanate from the landfill and flow into the lagoon. The landfill likely forms a serious long-term threat to the lagoon and a study is needed with regards to the potential leaching of contaminants.

Although algology deals with a large group of plants, widespread and of great morphological diversity, the history of this branch of botany is fairly young. Linnaeus (1753) listed in his Species Plantarum under the heading “Cryptogamia — Algae” only five genera of plants are still accepted as algae at the present time. Under the same heading, he also described a number of liverworts, lichens and sponges, and a few other things.

During the last few decades, however, algological knowledge has increased to such an extent that it must be considered impossible to cover the whole field of phycology in one general work. Fortunately, from the nineteenth and twentieth centuries, we have many local algal floras, a survey of which has been published by Taylor (1959b).

The history of algology, especially for the West Indies, has been treated at length by Taylor (1960) in his large and comprehensive work Marine algae of the eastern tropical and subtropical coasts of the Americas. After a stay at the Dry Tortugas Laboratory of the Carnegie Institution of Washington during the summer months of 1926—1928, Taylor published many articles and papers on marine algae from most parts of the Caribbean. Nevertheless, only a few places have been thoroughly investigated. 

The richest development of algae is found in the sublittoral region. Mostly in its uppermost part remarkable algal vegetation of short, closely branched, moss-like plants have developed. Most species of this vegetation may also be observed in deeper, more quiet water, where they are much better developed. A number of species are found exclusively in exposed places. Very abundant at the same level is the urchin Echinometra lucunter, which has its lower limit at a depth of 45—50 cm. When a lot of sand is carried by the waves, species such as Chondria tenuissima and Digenea simplex are abundant. Much coral, especially Millepora alcicornis, may be found as high as the uppermost part of the sublittoral region

The total number of species (218) is considerably lower than that given by Borgesen for the Virgin Islands. Several reasons may be indicated to explain this difference. Our samples were taken by walking along the coast, or by swimming and diving; they only include specimens from a rather narrow and shallow strip along the shore. Borgesen, however, also got samples from a greater depth. He visited the Virgin Islands several times and was able to pay special attention to difficult groups. Furthermore, much attention was given by him to very small epiphytes, for instance, the genus Acrochaetium, of which several new species were described. Our investigation confirms the conclusions by Taylor (1955). The Caribbean marine flora is an exceedingly rich one. After the elimination of early and ill-described species still, 790 well-defined species are known.

The study of the extensive collection of marine algae collected in the Netherlands Antilles during our stay in 1957/58 was started with the material from the islands of St. Martin, St. Eustatius, and Saba (Lesser Antilles). The algal vegetation of Aruba, Bonaire, and Curaçao will be treated in separate publications. The book contents describe below:

• Introduction
• Habitat Factors
• Survey of the Literature on the Algal Vegetations in the Caribbean
• Survey of the Observations on the Algal Vegetations of St. Martin, St. Eustatius, and Saba
• Summary and Discussion

The Netherlands Antilles comprise the islands Aruba, Curaçao and Bonaire of the Leeward Group, and St. Eustatius, Saba and the southern part of St. Martin (St. Maarten) of the Windward Group. The northern part of St. Martin belongs to the French territory (Departement de la Guadeloupe). Botanical investigations were started already in the 18th century, but it was not before 1909 that an enumeration of the vascular plants of part of the Netherlands Antilles appeared in print (Boldingh, 1909; the other part appeared in 1914). In 1913 Boldingh published a Flora of the Netherlands Antilles (in Dutch). Brother M. Arnoldo published a Flora of Curaçao, Aruba and Bonaire (in Dutch, 1954; second edition 1964). An elaborate study of the vegetation of the islands was published by Stopfers (1956). Some of the data given below are borrowed from that paper. A new Flora is now in the course of publication (edited by Stoppers since 1962). This article describes the mosses family, species, location, and habitat preference that have been collected by the author in the Netherlands Antilles. The mossflora of the Leeward Group is very poor. It seems that no mosses have been collected in Aruba. Although the rainfall in Bonaire is distinctly higher than in Aruba, only 3 mosses, Hyophila microcarpa, H. tortula and Gymnostomiella orcuttii, have been collected on this island up till now. From Curaçao 6 species are listed below, five of which have been collected on the highest hill. The Windward islands Saba and St. Eustatius have by far the richest bryoflora of the Netherlands Antilles. This mainly due to the higher elevation (St. Eustatius 600 m and Saba 900 m) and to the higher rainfall.

The present paper deals with the Anasca and Ascophora Imperfecta of the inland bays of Curaçao and Bonaire. Collections were made by P. Wagenaar Hummelinck (1930, 1936/ 37, 1948/49, 1955, 1963/64, 1968, 1970, and 1973) and by the author (1982), and stored in the collections of the Rijksmuseum van Natuurlijke Historie, Leiden. A total of 25 species – almost all occurring in inland bays – are described here and fully illustrated. Six new species are established: Crassimarginatella harmeri, Scrupocellaria curacaoensis, Scrupocellaria carmabi, Scrupocellaria piscaderaensis, Scrupocellaria hildae and Bugula hummelincki. Attention is given to the ecology of the species. The bays have been compared as to species composition in relation to substrate and conditions during collecting.

The Island of Bonaire has a system of natural caves that probably exceeds 150 in number. Those caves house at least five species of bats: Leptonycteris curasoae, Mormoops megalophylla, Natalus tumidirostris, Myotis nesopolus and Glossophaga longirostris. The former four depend primarily or exclusively on caves as diurnal and maternity roosts. The IUCN Red List of Threatened Species considers L. curasoae as Vulnerable. Several studies have underlined the importance of this bat as a pollinator and long-distance seed dispersal agent of several species of succulent plants in northern South America. Likewise, indirect evidence suggests that between December and March part of the populations of Aruba, Curaçao and Bonaire abandon these islands and move to the arid and semiarid zones of Venezuela and Colombia. Until now, we did not know that L. curasoae reproduced on Bonaire, but during the last three years, studies conducted on the island have shown that it is important as a mating and maternity site for the species. At present, we have identified four caves used as maternity roosts. Mormoops megalophylla also reproduces on Bonaire, with at least two maternity caves. Recognition of the Washington–Slagbaai National Park and surrounding areas as an AICOM will contribute to protecting the main habitat types used by all species present on the island as food sources and roosts.

Have you ever seen an orange tail molly in Dutch waters? If not, you should go to the ABC Islands. That’s an abbreviation for Aruba, Bonaire, and Curaçao. These islands are located not far off the northern coast of Venezuela. In the small Antillean islands (i.e. the ABC islands) the population of mollies in the sea is small, probably because of the multitude of predators. However, this small population seems to be of utmost importance as it is a very stable one, in contrast to the populations of inland waters, both fresh and super saline (i.e. landlocked saltwater lagoons), which habitats seem to be more attractive than the sea. In the inland waters, however, mass mortalities occur of adverse conditions, both biotic and of abiotic nature. Therefore the inland populations are subjected to occasional extinction, and the habitats have to be repopulated from the sea. This may be the explanation that no genetically fixed differences could be found between populations from freshwater, from the sea and from super saline water. The inland migration after rainfall is not caused by the freshwater itself, but by an organic compound that is found in inland water, whether fresh or saline and also in rainwater after it has been in contact with the soil. So the next time you want to go scuba diving, snorkelling, or bird watching, why not choose the ABC islands? They are friendly, safe, and clean, and you can even drink the tap water! But do not forget to look for the local molly: Poecilia vandepolli.