Butterflies

Based on four years of butterfly monitoring in four contrasting natural habitats on St. Eustatius, we document large and consistent differences in the butterfly species assemblages in the different habitats and compare the butterfly assemblages of the three windward Dutch islands to those of other islands of the Lesser Antilles. Seven new species records were established for St. Eustatius, thereby updating the butterfly list to a total of 32 species. Pieridae were the most numerically abundant group of butterflies (48%), followed by Lycaenidae (26%), Hesperiidae (12%), and smaller numbers of both Heliconiinae (6%) and Charaxinae (5%). Heliconiinae and Charaxinae both showed a significant dependence on the moister, wind-sheltered habitats of the volcanic slopes and crater of the Quill, but this dependence was particularly strong for Heliconiinae. The butterfly faunas of the windward Dutch islands numbered a total of 44 species. The presence of larval host plants needed for local reproduction was confirmed for all but two species. Cluster analysis separated the butterfly faunas of these and the surrounding islands into two groups. The more speciose butterfly assemblages of Saba, St. Eustatius, and St. Martin clustered together with the those of the surrounding higher islands of Antigua, Montserrat, Nevis, and St. Kitts, while the poorer faunas of the low-lying islands of Anguilla, St. Bartholomew, and Barbuda formed a separate cluster and had a lower species richness particularly in the Heliconiinae and Charaxinae. Based on consistent effects of elevation on butterfly faunas, at both geographic scales (between areas on St. Eustatius and between islands), our results suggest that island maximum elevation is the overriding factor explaining the distribution of butterfly faunal richness in the northern Lesser Antillean islands studied.

This month’s issue focuses attention on a very important species group – butterflies. Due to their sensitivity to environmental conditions, butterflies may serve as bioindicators for local and global environmental change. In addition to butterfly inventories and research across our islands, five years of butterfly monitoring on St. Eustatius is beginning to produce clear trends that indicate broader ecosystem change.

Also in this issue, on Saba the seafloor of the well-known site ‘The Pinnacles’ has been surveyed for the third time since 1991, resulting in the most detailed map of the seabed to date, demonstrating the benefit of improving technology for nature conservation(ists).

• ‘Research of the Month‘: Butterflies of the Windward Islands
• Butterflies as Beautiful Bio-indicators
• Butterfly Monitoring Programme on Statia
• Underwater Mapping on Saba
• Overview of Research and Monitoring Efforts
• Calendar of Upcoming Events, Meetings and Workshops

Sinds 10 oktober 2010 maken de eilanden Bonaire, Sint Eustatius en Saba onderdeel uit van het Nederlandse staatsbestel. Met deze tropische eilanden is de biodiversiteit binnen Nederland enorm toegenomen. Ik heb ruim vier jaar bijgedragen aan de ontwikkeling van het milieubeleid in Caribisch Nederland. Op Sint Eustatius zijn ondanks de aanwezigheid van een grote Amerikaanse olieterminal en raffinaderij grote natuurparken op het eiland aanwezig. Vanwege de afgelegen ligging van het eiland is het aantal soorten vlinders er gering

Saba ligt in de Caribische Zee en is een van de drie eilanden die vroeger behoorden tot de bovenwindse eilanden van de Nederlandse Antillen. Sinds 10 oktober 2010 heeft Saba, net als Sint Eustatius en Bonaire, de status van bijzondere Nederlandse gemeente gekregen. Deze tropische eilanden zijn daarmee een onderdeel van Nederland geworden en Nederland heeft er zo een aantal heel bijzondere tropische natuurgebieden bij gekregen