Species

Nederlands below

Two recently published studies document 35 new beetle species for the islands of Saba and St. Eustatius.  Even with these latest additions, it is still estimated that nearly three quarters of the beetle population is still unknown.  Beetles play a vital role in breaking down natural waste and keeping insects in check, both important roles especially for small Caribbean islands.

The lady beetle Cycloneda sanguinea. Credit: Jan-Joost Mekkes

Beetles represent some of the tiniest inhabitants of the Dutch Caribbean but play a critical role in the environment.  They work as tiny decomposers and are vital in recycling nutrients from dead leaves and natural waste back into the ground.  As predators, they can help keep insect populations in check, especially pests like caterpillars and aphids which can damage crops.  Furthermore, with over 350,000 species worldwide, beetles represent a fifth of all living organisms in the world and nearly 40% of described insects.

Taxonomic Impediment

Unfortunately, there is still a lot that researchers don’t know about the beetle populations of the northern Leeward Islands.  Dubbed the “taxonomic impediment”, this is due to the gap between the local taxonomic knowledge and a shortage of trained taxonomists in the region.  In fact, it is estimated that only about 10-20% of the known beetle species of the islands have been correctly identified to date.

New Records

The firefly Aspisoma ignitum, Boven National Park, St. Eustatius. Credit: Jan-Joost Mekkes

Two new studies worked to bridge this gap for the islands of Saba and St. Eustatius.  Between 2008 and 2020, three researchers visited Saba and recorded a total of 22 different beetle species.  Of these, 14 were new to Saba or confirmed previously provisional records and four were new to the Dutch Antilles.  With this new study, the total number of beetle species recorded on Saba is now around 100.

In 2020, one researcher on St. Eustatius was able to collect 46 beetle species, of which 21 were new to the island, including 15 which were new to the Dutch Antilles.  Adding to previous records, this now brings the total number of known beetle species for the island to 117, which researchers believe to be about a quarter of the number of species expected.

The weevil Trichobaris bridwelli, Oranjestad, St. Eustatius. Credit: Jan-Joost Mekkes

Report your sightings

Have you observed any beetles or other insects?

Currently, researcher Jan-Joost Mekkes (jayjaymekkes@hotmail.com) is on Sint Eustatius and Michiel Boeken (michiel.boeken@gmail.com) on Saba.  Please forward them your beetle and other insect sightings.

Or submit your sightings and photos directly yourself on the website www.Observation.org or download the free apps (iPhone (iObs) & Android (ObsMapp)).

Species reports by local communities and tourists are invaluable for nature conservation efforts to help increase public awareness and overall species protection. Besides, DCNA, Observation International and Naturalis Biodiversity Center are working together to develop on automated species identification app for your phone. Your uploaded photos are of great value to make this possible. For questions, please contact research@DCNAnature.org

Read more

You can find the completed list of the beetle species documented during these studies in the Dutch Caribbean Biodiversity Database.

https://www.dcbd.nl/document/results-entomological-collecting-trip-st-eustatius-coleoptera

https://www.dcbd.nl/document/two-small-beetle-collections-saba-coleoptera

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Nieuwe kevers ontdekt in het Nederlands Caribische gebied

Twee recent gepubliceerde studies documenteren 35 nieuwe keversoorten voor de eilanden Saba en St. Eustatius. Ondanks deze laatste toevoegingen wordt geschat dat nog bijna driekwart van de keverpopulatie onbekend is. Kevers spelen een cruciale rol bij het afbreken van natuurlijk afval en het onder controle houden van insecten, beide belangrijk voor de Caribische eilanden.

Het lieveheersbeestje Cycloneda sanguinea, F.D. Roosevelt Airport, St. Eustatius. Credit: Jan-Joost Mekkes

Kevers zijn een van de kleinste bewoners van het Nederlands Caribisch gebied maar spelen een cruciale rol in de natuur. Ze werken als kleine ontbinders en zijn van vitaal belang bij het recyclen van voedingsstoffen uit dode bladeren en brengen natuurlijk afval terug in de grond. Als roofdieren kunnen ze helpen insectenpopulaties onder controle te houden, met name plagen zoals rupsen en bladluizen die gewassen kunnen beschadigen. Bovendien vertegenwoordigen kevers, met meer dan 350.000 soorten wereldwijd, een vijfde van alle levende organismen in de wereld en bijna 40% van de beschreven insecten.

Taxonomische belemmering

De vuurvlieg Aspisoma ignitum, Boven National Park, St. Eustatius/ Credit: Jan-Joost Mekkes

Helaas is er nog veel dat onderzoekers niet weten over de keverpopulaties van de noordelijke Caribische eilanden. Ook wel de “taxonomische belemmering” genoemd. Dit komt door de kloof tussen de lokale taxonomische kennis en een tekort aan opgeleide taxonomen in de regio. Er wordt zelfs geschat dat tot op heden slechts ongeveer 10-20% van de bekende keversoorten van de eilanden correct zijn geïdentificeerd.

Nieuwe waarnemingen

De snuitkever Trichobaris bridwelli, Oranjestad, St. Eustatius. Photo credit: Jan-Joost Mekkes

Twee nieuwe studies hebben deze kloof voor de eilanden Saba en Sint Eustatius overbrugd. Tussen 2008 en 2020 bezochten drie onderzoekers Saba en registreerden in totaal 22 verschillende keversoorten. Hiervan waren er 14 nieuw op Saba of bevestigde eerdere voorlopige waarnemingen en vier waren nieuw voor het Caribisch deel van het Koninkrijk der Nederlanden. Met deze nieuwe studie ligt het totale aantal geregistreerde keversoorten op Saba nu rond de 100.

Een onderzoeker op Sint Eustatius heeft in 2020 46 keversoorten kunnen verzamelen, waarvan 21 nieuw voor het eiland, waarvan 15 nieuw voor het Caribisch deel van het Koninkrijk der Nederlanden. Toegevoegd aan eerdere records, brengt dit nu het totale aantal bekende keversoorten voor het eiland op 117, wat volgens onderzoekers ongeveer een kwart is van het verwachte aantal soorten.

Rapporteer uw waarnemingen

Heb je kevers of andere insecten waargenomen?

Momenteel zit onderzoeker Jan-Joost Mekkes (jayjaymekkes@hotmail.com) op Sint Eustatius en Michiel Boeken (michiel.boeken@gmail.com) op Saba. Ze ontvangen graag uw kever- en andere insectenwaarnemingen.

Of upload uw waarnemingen en foto’s direct zelf in op de website www.Observation.org of download de gratis apps (iPhone (iObs) & Android (ObsMapp)).

Soortenrapporten door lokale gemeenschappen en toeristen zijn van onschatbare waarde voor inspanningen op het gebied van natuurbehoud om het publieke bewustzijn en de algemene bescherming van soorten te vergroten. Daarnaast werken de Dutch Caribbean Nature Alliance (DCNA), Observation International en Naturalis Biodiversity Center samen aan de ontwikkeling van een geautomatiseerde app voor het identificeren van soorten voor je telefoon. Uw geüploade foto’s zijn van grote waarde om dit mogelijk te maken. Neem voor vragen contact op met research@DCNAnature.org

Lees meer

De volledige lijst van de tijdens deze onderzoeken gedocumenteerde keversoorten vindt u in de Dutch Caribbean Biodiversity Database.

https://www.dcbd.nl/document/results-entomological-collecting-trip-st-eustatius-coleoptera

https://www.dcbd.nl/document/two-small-beetle-collections-saba-coleoptera

Published in BioNews 51 

Seagrasses, marine flowering plants, are widely distributed along temperate and tropical coastlines of the world. Seagrasses have key ecological roles in coastal ecosystems and can form extensive meadows supporting high biodiversity. The global species diversity of seagrasses is low (b60 species), but species can have ranges that extend for thousands of kilometers of coastline. Seagrass bioregions are defined here, based on species assemblages, species distributional ranges, and tropical and temperate influences. Six global bioregions are presented: four temperate and two tropical. The temperate bioregions include the Temperate North Atlantic, the Temperate North Pacific, the Mediterranean, and the Temperate Southern Oceans. The Temperate North Atlantic has low seagrass diversity, the major species being Zostera marina, typically occurring in estuaries and lagoons. The Temperate North Pacific has high seagrass diversity with Zostera spp. in estuaries and lagoons as well as Phyllospadix spp. in the surf zone. The Mediterranean region has clear water with vast meadows of moderate diversity of both temperate and tropical seagrasses, dominated by deep-growing Posidonia oceanica. The Temperate Southern Oceans bioregion includes the temperate southern coastlines of Australia, Africa and South America. Extensive meadows of low-to-high diversity temperate seagrasses are found in this bioregion, dominated by various species of Posidonia and Zostera. The tropical bioregions are the Tropical Atlantic and the Tropical Indo-Pacific, both supporting mega-herbivore grazers, including sea turtles and sirenia. The Tropical Atlantic bioregion has clear water with a high diversity of seagrasses on reefs and shallow banks, dominated by Thalassia testudinum. The vast Tropical Indo-Pacific has the highest seagrass diversity in the world, with as many as 14 species growing together on reef flats although seagrasses also occur in very deep waters. The global distribution of seagrass genera is remarkably consistent north and south of the equator; the northern and southern hemispheres share ten seagrass genera and only have one unique genus each. Some genera are much more speciose than others, with the genus Halophila having the most seagrass species. There are roughly the same number of temperate and tropical seagrass genera as well as species. The most widely distributed seagrass is Ruppia maritima, which occurs in tropical and temperate zones in a wide variety of habitats. Seagrass bioregions at the scale of ocean basins are identified based on species distributions which are supported by genetic patterns of diversity. Seagrass bioregions provide a useful framework for interpreting ecological, physiological and genetic results collected in specific locations or from particular species. © 2007 Elsevier B.V. All rights reserved. 

Catalog of Dutch Caribbean Species contains information on:

• habitat;
• names;
• presence and;
• collection specimens

The registeris searchable by:

• Photo search and;
• Taxonomic tree.

The Indo-Pacific lionfishes (Pterois volitans [Linnaeus, 1758] and P. miles [Bennett, 1828]: Family Scorpaenidae) are the first nonnative marine fishes to establish in the Western North Atlantic/Caribbean region. The chronology of the invasion was reported last year (Schofield 2009) using records from the US Geological Survey’s Nonindigenous Aquatic Species database. This article provides an update of lionfish geographic spread (as of October 2010) and predictions of future range

About 210 resident and migratory bird species are found on the island of Bonaire. More than half of these species are landbirds. Some of the landbirds are endemic subspecies. Despite its small area, Birdlife International designated five Important Bird Areas (IBAs) on Bonaire. This manual is a working tool for STINAPA employees and volunteers doing landbird surveys on Bonaire.

1) The monitoring program covers the areas considered potential habitat for feeding, nesting, and roosting of the selected species of landbirds on Bonaire. 2) Surveys are conducted at least twice per year (February-March and September-October). About 10 days are needed per sampling period. 3) Morning counts start after sunrise and stop at 10:00 hours. Afternoon counts start at 16:00 hours and stop before sunset. 4) At least two observers are needed for the collection of count and supplementary data related to habitat, food, disturbance, and other factors that may affect species detection and abundance at sampling units (fixed on-road and off-road points). 5) Additional information are collected about uncommon observations, such as large flocks in roosting areas, nesting activity, the presence of predators, and any other observation that may be of interest for research, monitoring, and management purposes. The location of these observations is recorded using GPS units. Date, time, and additional comments are also recorded. When possible photos are taken to provide complete documentation for future reference and consultation as needed. 6) Weather conditions are recorded as part of standard data collection. 7) Just like any other activity conducted by STINAPA Bonaire, human safety is always considered a priority over the completion of survey activities.

We here provide a synoptic overview and preliminary update of the marine mammals of the Dutch Caribbean EEZ based on 279 cetacean sighting and stranding records. The Dutch Caribbean EEZ is composed of two distinct sectors. One is centered around the leeward Dutch islands of Aruba, Bonaire and Curaçao (71,000 km2) while the other is centered around the windward Dutch islands of Saba, St. Eustatius and St. Maarten (22,000 km2). The previous principal review (of cetaceans) dating from 1998, was based on only 70 records from the leeward sector and confirmed the occurrence of some 13 species for Dutch Kingdom waters. Now, with a 4-fold increase in number of records, 19 species can be documented for the Dutch Kingdom waters (18 species in the leeward sector and 8 species in the windward sector).

The windward sector stands out for its large number of humpback whale sightings (45% of records) and may form part of its former (or current) calving grounds. This species remains relatively rare in the leeward sector (5% of records) and continues to be targeted by aboriginal fishing in its destination wintering grounds to the east, where the relict breeding population is having difficulty to rebound. The species is of growing interest to tourism in the region and urgently needs full protection from all fishing in the southern Caribbean. The leeward EEZ sector further lies down-stream from seasonal upwelling areas off Venezuela that support the largest fishery of the Caribbean. This sector stands out for its high occurrence of beaked whales and the Bryde’s whale. Marine mammal strandings are much more common here (26% of records) than in the northern sector (3% of records). Human induced mortalities (first suggested in 1974) and disturbance due to coastal tourism and recreation are key and growing concerns in the southern Dutch EEZ sector.

The marine mammal fauna of the Dutch Caribbean is evidently rich and varied but continues to suffer man-induced mortality and disturbance. Several nations, including the USA, the Dominican Republic and France, have recently established marine mammal sanctuaries in Caribbean waters. The Netherlands should consider doing the same.

There are 330 parrot species worldwide, of which a third is threatened with extinction. The Yellow-shouldered Amazon (Amazona Barbadensis) is a parrot species found in northern Venezuela and on the Caribbean islands Margarita, La Blanquilla and Bonaire. The total population size is estimated at 3.000-10.000 parrots, which has led the IUCN to classify its global condition as vulnerable. The population size on Bonaire is estimated at 800 parrots.
The goal of this study was to examine both the threats A. Barbadensis is facing on Bonaire and the opportunities to resolve them. Three methods were used during this process. First a literature study was conducted regarding the population dynamics of A. Barbadensis on Bonaire, resulting in a quantification of the different population parameters and environmental factors, affecting the parrot population. Secondly, a population dynamics simulation model was used to determine the sensitivity to changes in these environmental factors and population parameters. The model was finally used to analyze the impact of several scenarios on the population size over a period of 200 years.
The most important factor constraining the growth of the parrot population on Bonaire, is the limited number of nest sites in both trees and cliffs. Nest site limitation is inferred from the fact that only 21.5% of the population breeds annually. The low supply of tree cavities is caused by the exotic and invasive goats and donkeys who are responsible for the degraded state of the vegetation since their introduction in the 16th century. An eradication program would allow the ecosystem to restore to its natural balance. A. Barbadensis would benefit by increased survival in all life stages due to a substantial increase in food resources, which will prevent the parrots from having to visit the hazardous urban areas, and by an increase in the number of nest sites. The scenario exploring the effects of this drastic measure reveals a population growth to several thousands of parrots.
It must be noted however that this scenario does not include any density dependant factors that would eventually limit the growth rate.
The population is most sensitive to changes in juvenile and adult survival, which corresponds with the r/K selection theory and another theoretical viability study regarding A. Barbadensis. Conservation initiatives should therefore focus on increasing their survival as it will be more beneficial to the persistence of the species than improving upon chick survival and female reproductivity.
The exact effects of climatic stochasticity on parrots are not well known. This study assumed the climate affected both survival in all life stages as well as reproduction. Changes in the impact of the climatic stochasticity showed a high sensitivity, which emphasizes the need for a better understanding of the impact the climate has on the survival and reproductive parameters of A. Barbadensis. The parrot population on Bonaire can be considered as viable as the current conditions will not lead to extinction, nor will any of the other scenarios examined in this study. However, the reality might consist of a combination of these scenarios, affecting the parrot population more severely. It is therefore recommended, as a bare minimum conservational approach, to maintain the annual count of the population size in order to readily notice a decline in population size, enabling counter measures to be taken accordingly.

The Lesser Antilles include high volcanic islands with a limited marine shelf, and low coralline islands with a more extensive shelf. Withinthe group, reefs are affected to a greater or lesser degree by widely differing conditions of rainfall and runoff, hurricane damage, recreational use and fishing pressure. While degradation is reported in many areas, there are few long-term studies that quantify trends in reef status. In recent years there has been an increase in the number of management initiatives, and in the number of reef areas under active and effective management. 

General description 

New observations indicating undesirable trends on Bonairean reefs 

Unusual high abundances of the colonial tunicate Trididemnum on Bonaire’s Northwestern reefs

 Population explosions of coral and gorgonian eating snails 

Overgrowth of deeper reefs by the brown alga Lobophora variegata 

Increased abundance of coral‐destroying territorial damselfish 

Unprecedented predation on native fish by the invasive red lionfish 

 Historic factors negatively affecting the “health” of Bonaire’s reefs 

Current situation 

Unknown stressors for Bonaire’s reefs 

Conclusions