Madden, H.

In October 2016, a two-year project to increase awareness and understanding of nature on St. Eustatius commenced, funded by the Ministry of Economic Affairs (MinEZ) and facilitated through the Caribbean Netherlands Science Institute (CNSI). Public awareness and community outreach is of critical importance in order to gain the support of the local community, and to promote efficiency among the various stakeholders pertaining to new nature and environmental plans. Public support for nature can be enhanced enormously, when people see the link between nature and their own interests like economic prosperity.

This news-item was published in BioNews 10-2017.

An immediate concern after hurricanes Irma and Maria fell to the Bridled Quail-dove, a species that forages for fruits and seeds on the forest floor. The Quill is the only habitat on Statia that supports the quail-dove, and we had conducted a population assessment in May 2017 in connection with a rodent control project that is being facilitated through the Caribbean Netherlands Science Institute (CNSI). Our initial results were encouraging, with an estimated 1,030 (standard error [SE] = 275, 95% confidence interval [CI] = 561-1,621) quail-doves across its local habitat of 440 hectares, possibly the highest known density in the region. For this reason, and thanks to the generous persons that supported BirdsCaribbean’s fundraising appeal, we were able to repeat the survey in November to assess the population post-hurricane. 

This news-item was published in BioNews 9-2017.

Reprinted with permission from BirdsCaribbean

The avifauna of the Dutch Caribbean island of St. Eustatius has been little studied. We document 22 new bird species for the island and update the status of several important species based on our recent observations. The documented avifauna of the island amounts to 75 published species records. We conclude by pointing out several positive developments in the avifauna and ascribe these to the combined effects of reduced hunting, the legal establishment of protected park areas, and a growing environmental awareness among the island’s inhabitants.

The original description of Ipomoea sphenophylla by Urban in 1908, based upon a fruiting specimen, did not include a description of the owers. The holotype was subsequently lost and plants in ower were recol- lected in 1994; a neotype was then designated by Howard and McDonald in 1995. An amended description of the species was also supplied, detailing the characteristics of the cotyledons, a swollen root system, and dimorphic owers. The owers were described as including a more common morph with a normal funnelform corolla, and an abnormal morph having a 3–5 polypetalous corolla. Presently, both morphs occur together on one sterile individual that is located in the area where the neotype was collected. We have examined approximately 150 addi- tional plants, and all contain funnelform owers. The polypetalous morphology is therefore atypical of Ipomoea sphenophylla. The species description is emended and the reference to polypetalous owers is removed. 

Student report

Abstract

A reptile species that suffers from anthropogenic changes is Iguana delicatissima. This species was common on all Lesser Antillean islands from Martinique to Anguilla but since 1996 the species is vulnerable. Nowadays, however, the species only exists on St. Eustatius in the Dutch Caribbean. Native plant species might be dependent on I. delicatissima and its extinction could lead to biodiversity loss on St. Eustatius. Therefore it is important to gather as much data as possible on population size, feeding behaviour and habitat preferences, as well as create artificial nests. The information provided by this research can help the future conservation of I. delicatissima. Information about habitat preferences and feeding behaviour was documented. To create wooden artificial nests a literature study was used. A total of 128 individuals were located across the island during a secondary beading study, primarily next to roads. I. delicatissima were found in different trees and bushes and were documented eating invasive plants like Antigonon leptopus but also native plants such as Citharexylum spinosum. Earlier research on reptiles suggests that roadsides and surfaces attract reptiles for thermoregulatory purposes. Non-native plant species do not appear to have much influence on I. delicatissima. The 128 individuals located is below the recommended minimum viable population size of 5000 animals, however it is not currently possible to give an accurate population estimate from this study. There are a number of different threats to the population, such as free-roaming pets, habitat loss and habitat degradation. To conclude, more research is needed for the future conservation of I. delicatissima. 

Please contact STENAPA (research@statiapark.org)

Raw data of terrestrial bird observation on St.Eustatius by STENAPA. Observation include habitat, observer, plot, transect/point observation, species, number of individuals, heard/seen the bird, distance, etc.

Please contact STENAPA for more information.

Red-billed tropicbird peak attendance and nesting success on St.Eustatius. 

Please contact Hannah Madden for more information.

The Lesser Antillean island of St. Eustatius harbors two native anole species, the large Panther or Statia Bank and the smaller Schwartz’s or Saint Kitts Bank Bush Anole (A. schwartzi; max. SVL 53 mm). No exotic anoles had been reported for the island until a stray individual of the lizards Saba Anole (Anolis sabanus) was discovered in the harbor of Oranjestad, St. Eustatius in April 2016, marking the first recorded introduction of the species. 

In 2013, the invasive Giant African Land Snail, Achatina fulica was found in a small part of urban St. Eustatius. In collaboration with local government agencies and Dutch universities we conducted field and laboratory pilot trials of control methods from October 2015 to June 2016. From the initial two gardens in 2013, the species has since been confirmed in 37 gardens encompassing an epicentre of about 100 lots in the Bay Brow area. During the study period, application of eco-friendly iron-phosphate snail bait successfully prevented further spread into adjacent buffer-zone monitoring areas. Iron-phosphate snail bait was effective in greatly reducing snail population density. It was applied once a week at an average density of 0.7 g/m2 at garden level, but was concentrated in hotspot snail habitat areas. Nevertheless, hand picking, which is more labour intensive and gives more variable results, also appeared effective in reducing snail density. Finally, beached Sargassum seaweed, brought forth as a snail deterrent used on neighbouring islands, did not measurably kill snails above zero control levels, and we conclude that seaweed is unlikely to be effective in snail control. 

Iguana delicatissima sightings on St. Eustatius, supported by RAVON (Reptiles, Amphibians and Fish Research Netherlands),  STENAPA and the MSc theses of Thijs van den Burg (Vrije University Amsterdam) and Tim van Wagensveld (Wageningen University and Research).

See this report for more information on the survey.