Freitas, J.A. de

 A new species of palmetto, Sabal antillensis , native to Curaçao and Bonaire, is described and illustrated. The new species is

characterized by a pachycaulous habit, a compact crown of leaves, large seeds, and frequent fiber bundles in leaflet transection.

Details on history, morphology, distribution, habitat, and conservation status are provided.

Following the Caribbean Waterbird Census Monitoring Training workshop given by Lisa Sorenson (BirdsCaribbean) and Je Gerbracht (Cornell) at Carmabi in January 2015 and sponsored by DCNA, a group was set up whose goal was to monitor some of the most important aquatic areas on Curaçao. 

This news article was published in BioNews 25.

BioNews is produced by the Dutch Caribbean Nature Alliance and funded by the Ministry of Economic Affairs.

A semi-detailed landscape-based vegetation map (scale: 1: 37,500) is presented for the 13 km2 Lesser Antillean steep volcanic island of Saba, Netherlands Caribbean. The map is based on a total of 49 vegetation plots that were sampled in 1999 using a stratified random sampling design and analysed using TWINSPAN cluster analysis. Three hundred and fourteen (314) plant species, representing 56% of the total known flora (565 species), were recorded in the sample plots. The principal lower sections of the island possess a tropical savannah climate whereas the upper slopes reaching a maximum altitude of 870 m can best be characterized as a tropical rainforest climate.
A total of two main and nine different sub-landscape types were distinguished based on geology, geomorphology and nine distinguished vegetation types. In Saba, sharp contrasts in soil, geomorphology and climatic factors are found on a small spatial scale and this meant that compared to the other islands of the Dutch Caribbean there is little mixing and merging of vegetation types at the landscape vegetation level. Consequently, vegetation type translates relatively directly into landscape vegetation units. Aside from important contrasts in vegetation that correspond to what is known about differences in soil and climate, our study also shows that large vegetation changes have taken place on the island since the survey by STOFFERS, five decades earlier. These largely appear to be due to three major forces: a) hurricane impacts; b) natural succession made possible due to diminished agricultural activity and; c) invasive plants and plant pest species.
The most recent hurricane, hurricane Georges, which struck the island one year before this study, clearly caused much damage to the vegetation, especially high on Mount Scenery. As a consequence, the elfin woodland vegetation has virtually disappeared, while remnant sections have been radically altered. Based on studies elsewhere in the region, the elfin woodland can be expected to take very long (if at all) to gradually recover. The impact of various hurricanes in the last 60 years has clearly caused major disturbance of the vegetation throwing it back into earlier stages of succession. The development of the “Tree fern brake” into “Pioneer forest” vegetation must be seen as a positive change where a secondary community had entered a higher stage in the sequence of succession. The virtual disappearance of the formerly prominent secondary shrub communities like Miconia thickets, Piper dilatatum thickets and Leucaena thickets can also be seen as likely evidence of natural successional forces thanks to diminished agriculture and woodcutting. Invasive species was the third major force of change that clearly appears to have been active on Saba in recent decades. The lasting impacts of insect invaders which have decimated formerly prominent Opuntia (cactus) and Tabebuia (tree) populations testify to the impact of invasive species as a major driver of recent vegetation changes on Saba.
Our field data show that most wilderness areas of Saba remain strongly affected by roaming grazing goats even though the contribution of goats to the local island economy is negligible. Goat dung or traces of grazing were recorded in or adjacent to 46% of the sample plots. Grazing by exotic mammals reduces the resilience of natural vegetation types and interferes with natural succession. Highest livestock densities and impacts seem to be in the more vulnerable coastal arid zones along the western and southern sections of the island with poor soil conditions and more open and shrubby vegetation. The development of ‘Dry evergreen woodland’ under similar conditions on the more remote, windy and salt spray-affected, but less-grazed, northern sectors of the island, suggest that those disturbed areas of the southern and western coastal zones should have potential for woodland recovery if and when goat grazing is reduced. Therefore, a key priority for terrestrial conservation in Saba should be to reduce feral grazer densities to allow vegetation recovery and reduce vulnerability to erosion. We suggest the use of pilot demonstration projects for grazer exclusion as a useful way to help build stronger arguments and public support for tackling the roaming goat problem in Saba.

Of the 3 species comprising the genus Leptonycteris Miller, L. curasoae has been the least studied with respect to its long-distance flights and potential for seasonal migrations. We studied long-distance movements between islands and between islands and the mainland in the Curaçaoan long-nosed bat. We used mark–recapture with periodic sampling and marking of bats in Aruba, Curaçao, Bonaire, and 1 location (Butare) in Falcón State, on the Venezuelan coastline. Between October 2008 and April 2014, we captured a total of 7,518 individuals at 11 sites (Aruba: n = 1,827, Curaçao: 778, Bonaire: 4,128, and Butare: 785). Between 78.3% and 98.0% of the bats captured at each island and mainland were marked, and the overall percentage of recaptured animals across all sampling sites was 8.31% (n = 529). L. curasoae inhabits the 3 islands year-round. On each island, it roosts in several caves, which can be used alternatively by the same individuals. Despite being a resident species, L. curasoae can perform long-distance oversea flights between islands and between islands and the South American mainland. A total of 11 long-distance flights were recorded (2 Bonaire–Aruba, 4 Bonaire–Curaçao, 1 Curaçao–Bonaire, 1 Bonaire– Venezuela, and 3 Aruba–Venezuela). We propose that populations of this species in Aruba, Curaçao, Bonaire, and Falcón State, Venezuela, exchange individuals, and part of the insular populations migrate seasonally southward as a response to cyclical changes in local resource availability and the yearly reproductive regime. 

Carmabi’s mission is to work towards a sustainable society, in which the sustainable management of nature
leads to benefits that future generations can also enjoy. All parts of our community should be involved in this
process.
Our primary goals are therefore:
• To conduct or facilitate research to support effective nature management, nature conservation, nature
restoration, and nature development;
• The acquisition, conservation, protection, management, restoration and development of natural areas in the
broadest sense, including objects or places of value to geology, history and/or archaeology;
• To create awareness within the community, especially school children, regarding the contribution they can
make to achieve sustainable development on Curaçao.
 
Retrieved from http://www.carmabi.org on April 13, 2015

Abstract:

In 2005 to 2006 we assessed the status of the Caribbean coot Fulica caribaea in the Netherlands Antilles, largely semi-arid islands in the South Caribbean, with small numbers of permanently available fresh water bodies. The Caribbean coot is a freshwater bird which is dependent on the seasonal availability of freshwater ponds for breeding; it breeds on 4 of the 6 islands of the Netherlands Antilles, viz. Curaçao (first recorded in 1956), Bonaire (1974), Aruba (1977), and St. Maarten (1981). Compared to the period up to and including 1979, group sizes in 1980 to 2006 were larger on Curaçao, and it appears more abundant in the latter period on all islands. We report on 49 sites (>5 ha) in the Caribbean where the species has been recorded, or where we would expect it to occur on the basis of available habitat. Threats to the Caribbean coot include drainage or reclamation of habitat, hunting, and pollution. Few sites receive protection. The coot has a restricted range of occupancy of some 1000 km2, spread out over 13 islands, representing 10 countries. Based on its restricted range, coupled with high levels of threat and the limited amount of protection, we recomend that the species be included as ‘Vulnerable’ in the IUCN (International Union for the Conservation of Nature and Natural Resources, World Conservation Union) Red List. An increase in the level of (legal) protection, in addition to an increase in the amount of habitat included in the regional protected areas network and heightening the awareness of the needs of this Caribbean endemic are overdue. The establishment of permanent freshwater ponds, especially in the arid parts of its range, appears favourable for the species, and may aid conservation. 

Summary:

This paper is intended as a basis for nature restoration activities using seeds of trees and (larger) shrubs native to Bonaire with the aim of reforestation. It describes the main seed biology issues relevant for species from this region, to facilitate decisions on time and stage of harvesting, safe storage, breaking dormancy and germinating seeds and planting the young trees in the field.

The paper also emphasises that natural process of seedling establishment and succession must be observed in order to be successful. The choice of species and method of protection once planted in nature will prove essential.

The paper ends with stressing that such a reforestation activity needs to be planned far ahead: seeds must be collected from tree species taking care of genetic diversity and their storage potential. Recalcitrant seeds (see paper) must be treated carefully and in a different way.

In Appendix I all knowledge from literature about collection, storage, germination and planting has been collected. Appendix II gives the growth characteristics of a selection of trees.

This report is part of the Wageningen University BO research program (BO-11-011.05-039) and was financed by the Ministry of Economic Affairs (EZ) under project number 4308701034. 

Summary:

Recent inventories have documented no less than 211 exotic alien species in the wild for the Dutch Caribbean. These amount to no less than 27 introduced marine species, 65 introduced terrestrial plants, 72 introduced terrestrial and freshwater animals and 47 introduced agricultural pests and diseases. A list of these species, pests and diseases are found in resp. Debrot et al. (2011), Van der Burg et al. 2012, and Van Buurt and Debrot (2012, 2011). The rate of introductions and establishment of invasive alien species (IAS) worldwide has grown rapidly as a result of increasing globalisation. Invasive species cause major ecological effects (decimating native flora or fauna populations) as well as economic losses to these islands, across sectors such as agriculture (diseases, weeds and vectors), fisheries (fish diseases and the lionfish), industry (rodents and termites), tourism (roadside weedy species) and public health (mosquitos). Recently in Curaçao the kissing bug Triatoma infestans was found; this is a vector for Chagas disease. It almost certainly came in with palm leaves imported from South America to be used as roof covering for recreational beach “palapa’s”.

Several countries in the Caribbean have developed a strategy to address the invasive species problem already, such as Jamaica (Townsend 2009), the Bahamas (BEST Commission 2003) and St. Lucia (Andrew and John 2010, Chase 2011). Islands are particularly at risk because of a number of factors: their small size, resulting in small vulnerable plant and animal populations, a relatively large border which is difficult to control, a small human population lacking the necessary expertise and resources to take adequate measures. For islands, the sea acts as a strong natural barrier for natural transport of terrestrial flora and fauna, however human activities helped in overcoming this barrier. The issue of feral animals, especially roaming cattle, donkeys, goats create similar problems everywhere: they have a devastating effect on tree and shrub regeneration, which greatly degrades the natural vegetation, with severe soil degradation as a result. This shifts the competitive advantage to hardy exotics and creates runoff of nutrients and silt into the sea, where algal growth and silt deposition are damaging the coral. The new nature policy plan for the Caribbean Netherlands assigns a high priority to the invasive species problem (MinEZ 2013), which worldwide is considered second only to habitat destruction as a long-term threat to biodiversity (Kaiser 1999, Mooney 2001).

While acknowledging a focus on the Caribbean Netherlands in specific (Bonaire, Saba, St. Eustatius) this report sets the first key steps in developing a common frame of reference for the whole of the Dutch Caribbean (i.e. including the islands of Aruba, Curacao and St. Maarten). These islands share historical and cultural ties, partly similar climates, scarce expertise, and experience most IAS as a common problem. The magnitude and severity of the problem is evident and necessitates a joint strategy into which action at insular level can be embedded for maximum efficiency and synergy: a common Invasive Alien Species Strategy (IASS).

Management Recommendations:

The main action points for implementation are:

1. Develop and adopt guiding legal lists for action: Black lists, Alert lists and Watch lists, enumerating the species for which border control is essential or for which control and management actions would be required. A special task group should be made responsible for keeping these lists up to date.

2. Install effective border controls. To prevent is better than to cure: the costs of controlling or eliminating invasives once established can be very costly. For this reason and because of the earlier indicated special vulnerability of the island ecosystems, it is strongly recommended to prevent the entrance of (more) invasives.

3. Establish Invasive Species Management Teams. For the coordination of data collection, evaluation and the initiation of actions, a special team is required. This ISMT team shall have its own facilities and budget.

4. Define responsibilities and mandates. Ultimate responsibility for IAS control lies with the island governments. This means that policies regarding IAS will be determined by the government. However, to be effective and efficient the ISMT (see 9.) needs full mandate to act within the limits of their own budget.

5. Require quarantine documents. Phytosanitary certificates and animal health certificates will be required for all imports.

6. Enforcement. Staff must be trained and instructed how to perform border controls. They must obtain sufficient mandate and means to confiscate and dispose of prohibited goods.

7. Develop action plans. A plan of action needs to be ready, describing the successive steps and decisions that have to be made for key threat species at all stages of the invasion process.

8. Arrange access to properties. When an alien species is invasive and needs to be eliminated, it is important that regulations allow the exterminators access to all properties, private and public alike.

9. Assure public support. Large scale programs for extermination and control, especially of animals, needs extensive public support. Volunteers may prove essential to assure enough ‘eyes’ and manpower.

10. Make rapid surveys. In order to decide whether a complete eradication is needed or that monitoring and restricting the distribution (mitigation) is the best or only option, a survey of the extent of the problem must be assessed by experts.

11. Rapid response. Usually a rapid action can localise the problem to a restricted area or eliminate the first individuals effectively so that no further costs have to be made.

12. Make risk assessments before introducing natural enemies. In case species are already present in vast numbers, biological control is often a last resort. This usually means introducing a natural enemy from the area of origin of the species. This means introducing another alien species, which may become a pest in itself. Expert consultation and small-scale experimenting is usually needed before the potential natural enemies can be safely released.

13. Create an information system. A team of experts managing a computer database is needed. This ISMT team needs to develop a system for easy reporting of new discoveries of alien species, for maintaining and updating information on key threats. The information system supports policy, action and research at all levels of the invasion process.

14. Create a platform for cooperation. In order to develop the system further, a national as well as an island platform is needed for participation of all relevant stakeholders. These platforms will develop recommendations for the ISMT and the island governments, and may also act as support group for the ISMT. 

Abstract:

Although the flora of Bonaire has been well studied three previously undocumented species have been found for Bonaire. Two of these three species are fern species and are new for the six islands of the Dutch Caribbean. The third species (Capparis linearis) occurs also on Curaçao and Aruba and is also a rare species on those islands. Data on the distribution of twelve rare species (eleven are previously unreported rare species for the Washington-Slagbaai National Park (WSNP) are also presented. A number of publications indicate the deleterious effects of introduced goats, donkeys and pigs on the vegetation and flora of islands. These animals are also found in the WSNP. The lack of saplings and the (very) small numbers of seedlings of only a few rare tree species found in the present study are ascribed to the deleterious effects of goats, donkeys and pigs. 

Abstract:

We conducted fieldwork on Bonaire and Curaçao, Netherlands Antilles, to assess the distribu- tion and abundance of resident diurnal raptors. In total, seventy-three 1 km2 sample plots were selected following a stratified random method and three landscape types were distinguished, i.e. cultivated area, hills and terrace. The diurnal raptors observed were the Crested Caracara Caracara plancus (93 records), White-tailed Hawk Buteo albicaudatus (37), and the American Kestrel Falco sparverius (44 on Curaçao only). In the hills and on the terraces, all species were more abundant on Curaçao than on Bonaire. Caracaras were found significantly more in hills compared to terraces or cultivated land on both islands, as did White-tailed Hawks on Curaçao. The American Kestrel made more use of cultivated area and least of hills. As detection of the raptors did not seem to differ between the landscapes and between the islands, we infer that the observed differences in distribution are a true reflection of their habitat use. Our results suggest that the ongoing urbanization on Curaçao and Bonaire may lead to a decline in the Caracara and the White-tailed Hawk. For the American Kestrel, cultivated areas – including urbanized parts – apparently provide the open area the birds need for hunting.