Madden, H.

Breeding Success of Red-billed Tropicbirds at Pilot Hill, St. Eustatius – Year 3 (2014-2015)

We assessed the breeding success of red-billed tropicbirds (Phaethon aethereus) at Pilot Hill on St. Eustatius, particularly in relation to predation at the nest. We conducted weekly surveys during 2014- 2015 and measured chick and adult morphometrics. Apparent hatching success was 57% and apparent fledging success was 73.7%, with reproductive success 37.8%. Camera traps installed in nesting cavities documented rats opportunistically scavenging eggs left unattended for even short periods of time. In total we confirmed nine predation events by rats at eight individual nesting cavities. Given the importance of St. Eustatius as a nesting site for red-billed tropicbirds, the implementation of a rodent control program is urgently required for the coming season. 

 

Date
2015
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

Goat Excluder Project in the Quill National Park Year 2

The presence of feral goats (Capra hircus) can have detrimental effects to island ecosystems where native plants have evolved in the absence of these animals. Feral goats are implicated in habitat destruction and alteration of species composition on sensitive island ecosystems. In the absence of population control, goats have become the ecologically dominant species on many islands, with the results that numerous endemic or native plant species have been extirpated, or are threatened by excessive grazing. It is demonstrated that the removal of goats can lead to rapid recovery of suppressed vegetation.
Nine excluders and nine controls were established randomly in three areas of the Quill. Data is collected annually every April. The size of each excluder and control is approximately 3m2. Overall a slight difference is apparent between the Quill control and excluder sites in 2014, with more plants present in the excluder plots than in the control plots.
 
Retrieved from STENAPA

Date
2014
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

Assessment of the Breeding Success of Red-billed Tropicbirds on St. Eustatius

We assessed the breeding success of Red-billed Tropicbirds Phaethon aethereus on St. Eustatius, particularly in relation to predation at the nest. We conducted weekly surveys at five sites during 2012-2013 and measured chick and adult morphometrics. Apparent nest success ranged from 55-100% across five breeding areas, while apparent fledge success ranged from 63-100% at those same locations. We used cameras and baited rat traps to document the presence of predators at nest sites. Predation rates captured on cameras were low (ca. 20 images of predators from ca. 263,000 images over 11 weeks). Cameras documented cats and rats at accessible nests. Although we could not confirm the cause of egg loss or the death of some chicks, the presence of cats and rats suggests that additional effort be expended to accurately measure their impact.
 
Retrieved from http://www.statiapark.org on April 13, 2015

Date
2013
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius

Important Bird and Biodiversity Areas (IBA) map of Bonaire

Important Bird and Biodiversity Areas (IBA) map of Bonaire (GIS).

See Bird life international website for program description

Date
2013
Data type
Maps and Charts
Theme
Research and monitoring
Document
Geographic location
Bonaire

Breeding success of Red-billed tropic birds at pilot hill, St.Eustatius - a follow up study (2013-2014)

Assessment of the breeding success of Red-billed Tropicbirds (Phaethon aethereus) at the Pilot Hill site on St. Eustatius, particularly in relation to predation at the nest. We conducted weekly surveys during 2013-2014 and measured chick and adult morphometrics. Overall apparent hatching success was 64.6%, while apparent fledging success was 75.6%. We used cameras to document the presence of predators at nest sites and wax bait blocks to estimate rat density. Camera traps documented rats opportunistically scavenging eggs that were left unattended for even short periods of time. In total we documented nine predation events of eggs by rats at eight individual nesting cavities.

Date
2014
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

Assessment of the Breeding Success of Red-billed Tropicbirds on St. Eustatius

Abstract:

We assessed the breeding success of Red-billed Tropicbirds Phaethon aethereus on St. Eustatius, particularly in relation to predation at the nest. We conducted weekly surveys at five sites during 2012-2013 and measured chick and adult morphometrics. Apparent nest success ranged from 55- 100% across five breeding areas, while apparent fledge success ranged from 63-100% at those same locations. We used cameras and baited rat traps to document the presence of predators at nest sites. Predation rates captured on cameras were low (ca. 200 images of predators from ca. 263,000 images over 11 weeks). Cameras documented cats and rats at accessible nests. Although we could not confirm the cause of egg loss or the death of some chicks, the presence of cats and rats suggests that additional effort be expended to accurately measure their impact. 

Date
2013
Data type
Research report
Theme
Research and monitoring
Geographic location
St. Eustatius

Notes on the Flowers and Distribution of the Caribbean islands endemic Ipomoea sphenophylla (Convolvulaceae)

Abstract:

The original description of Ipomoea sphenophylla by Urban in 1908, based upon a fruiting specimen, did not include a description of the flowers. The holotype was subsequently lost and plants in flower 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 flowers. The flowers 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 indi- vidual that is located in the area where the neotype was collected. We have examined approximately 150 addi- tional plants, and all contain funnelform flowers. The polypetalous morphology is therefore atypical of Ipomoea sphenophylla. The species description is emended and the reference to polypetalous flowers is removed. 

Date
2012
Data type
Scientific article
Theme
Research and monitoring
Geographic location
St. Eustatius

The Lesser Antillean Iguana on St. Eustatius: A 2012 population status update and cause for concern

To assess the status and current population densities of the endangered Lesser Antillean Iguana (Iguana delicatissima) on the island of St. Eustatius, we spent more than 80 h searching for iguanas and covered more than 63 km of trails and tracks — but found only 22 iguanas, for an overall average of 3.7 h per iguana. Overall population density was 0.35 iguanas per hectare, which represents 0.5–1.0% of densities documented elsewhere in healthy populations. Population densities have declined across all habitats since the last assessment in 2004. The lack of nesting sites and high iguana mortalities due to anthropogenic causes were the two core factors limiting recovery of iguanas on St. Eustatius.

Our principal recommendations are to:

  • (a) Train and equip border officials to prevent potential entry of mongooses and Green Iguanas from neighboring islands;
  • (b) implement enforcement and upgrade protective legislation;
  • (c) develop and maintain new additional nesting habitat, a measure that is both easy and inexpensive; and
  • (d) establish a program to promoto "iguana-friendly" gardens as the main means of reducing cumulative mortality.

Finally, we propose the development of an in situ husbandry and breeding program to help bolster the overall recovery program, a move that would also benefit islanders by offering a relaxed setting in which they could better learn to appreciate this emblematic island species.

Date
2013
Data type
Scientific article
Theme
Research and monitoring
Geographic location
St. Eustatius

Preliminary checklist of the bees of St. Eustatius, Lesser Antilles (Hymenoptera: Apoidea: Anthophila)

A preliminary checklist of bees is presented (Hymenoptera: Apoidea: Anthophila) compiled for St. Eustatius, an island located in the Lesser Antilles of the eastern Caribbean. The list has nine species, including six that have not been previously documented on St. Eustatius. One species is exotic to the Caribbean, one species is found only on St. Eustatius and St. Kitts, and five species occur elsewhere in the Lesser and Greater Antilles. Two of the collected specimens could not be assigned to a species; their geographical distributions are unknown. 

Date
2013
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
St. Eustatius

The scorpions (Arachnida: Scorpiones) of Sint Eustatius, Lesser Antilles

In the present note, we revise the scorpion fauna of the small island of Sint Eustatius, in the Lesser Antilles. A total of two families, three genera and three species are confirmed to occur there: the buthids Centruroides barbudensis (Pocock, 1898) and Isometrus maculatus (DeGeer, 1778), and the scorpionid Oiclus purvesii (Becker, 1880). These include the first record of the occurrence in Sint Eustatius of the family Scorpionidae and the genus Oiclus Simon, 1880, as well as the first published findings of I. maculatus since 1942. A key to the easy identification of all three species is provided.

Date
2012
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
St. Eustatius