Verdaat, J.P.

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

Data type
Maps and Charts
Research and monitoring
Geographic location

Aerial surveys of marine mammals and other fauna around Aruba, Curaçao and Bonaire, November 2013


In November 2013 aerial surveys were conducted for the first time in the Exclusive Economic Zone of Aruba, Curaçao and Bonaire to evaluate aerial surveys as a tool for marine mammal surveys in these waters, and to assess the distribution and abundance of marine mammals. A secondary aim of these surveys was to collect data on the occurrence of other megafauna (e.g. sharks, rays, turtles) and seabirds. Marine mammals were assessed using distance sampling methods; for other species a strip transect method was applied.

Four marine mammal species were sighted, all of them cetaceans: Humpback Whale, Atlantic/Pantropical Spotted Dolphin, Bottlenose Dolphin and Rough-toothed Dolphin. The total number of individuals seen was 107. Numbers of sightings were too low to calculate densities and abundance estimates for any of the species recorded.

In addition to the marine mammals, sharks, rays, turtles and seabirds were recorded. Noteworthy observations include the first record of a (living) Basking shark and records of seabirds that are scarcely documented in these waters: Red-billed Tropicbird and either Great Skua or South Polar Skua. The number of sightings for these groups were too low to calculate densities and abundance estimates for any of the species recorded.

This survey was commissioned by the Dutch Ministry of Economic Affairs (EZ), and World Wildlife Fund The Netherlands. 

Data type
Research report
Research and monitoring
Report number
Geographic location

Cruise report seabird and cetacean survey Saba bank expedition October 2011


In October 2011 an expedition took place to the Saba Bank, on board of the ship the Caribbean Explorer II. Main aim of the expedition was collecting data on underwater fauna and coral reefs. Apart from that data were collected on nutrients, water flow, sponges and seabirds and marine mammals. Data on the last group were collected by deploying acoustic data loggers, and by means of visual surveys. These visual surveys were conducted whenever the other activities permitted it. This cruise report presents an brief overview of the results obtained during the October 2011 survey. It contains a short day to day report, a full list of all birds, mammals and particular pieces of floating matter seen, and a brief presentation of the results. Furthermore the report contains a brief account of observed birds on Sint Maarten, since published accounts on the birdlife of the island are scarce.



  • The seabirds most often spotted were the Brown Booby and the Magnificent Frigatebird.
  • No marine mammals were observed.
  • Red-Billed Tropicbirds were primarily spotted near the shore of Saba.

Birds on Sint Maarten

The first ever records of the following birds were made during this expedition:

  • Cinnamon Teal (possibility of a hybrid cannot be excluded).
  • Marbled Godwit (flying over the Great Salt Pond).
  • A Merlin was seen hunting amongst Cliff Swallows and Barn Swallows.
  • Three Ospreys were recorded.
  • Breeding Caribbean Coots or adults with chicks were seen at several small ponds and in the salines.

Most Common (sighted>10)

  • Cattle Egret (Bubulcus ibis)
  • Snowy Egret (Egretta thula)
  • Magnificent Frigatebird (Fregata magnificens)
  • Brown Pelican (Pelecanus occidentalis)
  • Black-necked Stilt (Himantopus mexicanus)
  • Spotted Sandpiper (Actitis macularius)
  • Carib Grackle (Quiscalus lugubris)
  • Bananaquit (Coereba flaveola)

Least Common (sighted<2)

  • Merlin (Falco columbarius)
  • American Oystercatcher (Haematopus palliatus)
  • Wilson's Plover (Charadrius wilsonia)
  • Short-billed (Dowitcher Limnodromus griseus)
  • Wilson's Snipe (Gallinago delicata)
  • Marbled Godwit (Limosa fedoa)
  • Whimbrel (Numenius phaeopus)
  • Solitary Sandpiper (Tringa solitaria)
  • Lesser Black-backed Gull (Larus fuscus)
  • Cabot's Tern (Thalasseus acuflavidus)
  • Eurasian Collared Dove (Streptopelia decaocto)
  • Rose-ringed Parakeet (Psittacula krameri)
  • Yellow-billed Cuckoo (Coccyzus americanus)
  • Green-throated Carib (Eulampis holosericeus)
  • Antillean Crested Hummingbird (Orthorhyncus cristatus)
  • Northern Parula (Parula americana)
  • Caribbean Elaenia (Elaenia martinica)
  • Pearly-eyed Thrasher (Margarops fuscatus)
  • House Sparrow (Passer domesticus)
  • Northern Parula (Parula americana)
  • Blackpoll Warbler (Dendroica striata)
  • Prothonotary Warbler (Protonotaria citrea)


The vessel that was used during this survey was not well suited for dedicated seabird and cetacean surveys. However, the gathered data fits in well with the seasonal pattern in observed seabird species and densities described for Guadeloupe for the same time period (distinct dip from August to October). According to Debrot et al, there are few records of cetaceans in October.

Data type
Research report
Research and monitoring
Report number
Geographic location
Saba bank
St. Maarten

Important Bird Areas in the Caribbean Netherlands


The Important Bird Area (IBA) programme is an initiative of BirdLife International aimed at identifying, monitoring and protecting a network of key sites for the conservation of the world's birds. On the islands, Bonaire, Sint Eustatius (Statia) and Saba, nine IBAs have been designated in recent years. Prior to this study the boundaries of these areas were imprecisely defined and the specific ecological values of these areas were poorly documented and did not provide sufficient footing for further legal protection. In this report we compile available information, add recently collected field data and precisely define boundaries based on ecological and planning criteria so as to furnish the level of documentation sufficient to allow further legal designation and protection by island governments.

In this report we specifically:

  • document the most important ecological values represented in each IBA
  • define exact boundaries based on ecological and planning criteria and pinpoint core areas that can be distinguished for each IBA 
  • discuss the IBA’s spatial context within development and/or land-use plans
  • identify potential factors and developments that threaten the long-term spatial and ecological integrity of each IBA
  • determine which measures are needed to maintain the spatial and ecological integrity of each IBA.

On Saba one IBA is identified: Saba coastline IBA (AN 006). The 2,145 ha IBA of Saba lacks any form of legal designation as a protected area. Its value is especially based on breeding seabirds, most importantly the Red-billed Tropicbird and the Audubon’s Shearwater. In addition to legal designation, measures needed to protect the values of this IBA include eradication or control of predators such as cats and rats, and management of the garbage dump to limit the number of these predators. On Saba no gaps in IBA coverage are identified.

On Sint Eustatius two IBAs are identified: Boven (AN 007) and The Quill (AN 008). In contrast to Saba, the two IBAs of St. Eustatius enjoy almost full legal designation as protected park areas. Based on our findings we propose an extension of the 1,106 ha Boven IBA to include Signal Hill for its concentration of nesting Red-billed Tropicbirds. The problems caused by cats and rats are much less acute on Statia than on Saba. The value of the 472 ha Quill IBA is largely based on the resident breeding landbirds it supports. Key threats include goats and possibly feral chickens.

On Bonaire six IBAs are identified: Washington-Slagbaai National Park (AN 009), Dos Pos (AN 010), Washikemba-Fontein-Onima (AN 011), Klein Bonaire (AN 012), Lac Bay (AN 013), and Pekelmeer Saltworks (AN 014). The IBAs are designated as “nature” or “open landscape” in the Nature Policy Plan Bonaire spatial plan, thus enjoying protection. 

Washington-Slagbaai National Park (AN 009). (Size: 7,529 ha.) 
The Slagbaai IBA covers a diversity of habitats ranging from coastal lagoons to vegetated hillsides. Key values include its habitat value for Yellow-shouldered Amazon, nesting terns and foraging (West-Indian) Flamingos. Most of the area is legally protected either as an island park or with Ramsar status and actively managed. Key threats include overgrazing by feral goats and pigs. Poaching of the Yellow-shouldered Amazon is also a significant problem. Disturbance of tern colonies also occurs due to inappropriate routing of vehicles close to the important nesting island in the Slagbaai lagoon.

Dos Pos (AN 010) (Size: 293 ha.)
Dos Pos IBA is relatively small and largely has no legal protected status. It is an important freshwater site and is both of importance to resident species of which Yellow-shouldered Amazon is the most threatened worldwide. 

Washikemba-Fontein-Onima (AN 011) (Size: 6,286 ha.)
The Washikemba-Fontein-Onima IBA includes critical habitat for the Yellow-shouldered Amazon, nesting terns and the Caribbean Coot. About half the area is legally designated as either as “Island Park” or “Protected Landscape” in the Nature Policy Plan Bonaire. 

Klein Bonaire (AN 012) (Size: 2,052 ha.)
The Klein Bonaire IBA enjoys full legal protection being designated as a local conservation area and as an internationally recognized Ramsar wetland. The island and surrounding reef are protected within the Bonaire National Marine Park. It is principally of value as a tern nesting island. The woodlands are recovering since complete removal of goats from the island.

Lac Bay (AN 013) (Size: 2,117 ha.)
The Lac Bay IBA enjoys legal designation both as an island conservation area and as international Ramsar wetland site. The mangroves and salt flats are of local significance to nesting terns and hold a breeding population of the Reddish Egret (IUCN-status Near-Threatened).

Pekelmeer Saltworks (AN 014) (Size 6,197 ha.)
The Pekelmeer Saltworks IBA covers about one fifth of the island of Bonaire. Only the 55 ha “Flamingo Sanctuary” and the Pekelmeer enjoy island legal protected status and Ramsar wetland status, while most of the area is used as saliña by the Cargill company. Key IBA values in this area include the nesting colony of the Caribbean Flamingo, and nesting colonies of various tern species. The construction of isolated islands that will not be subject to industrial traffic along the dikes of the managed ponds should provide suitable nesting habitat for recovery of tern nesting in this area of the island. The Laughing Gull population of Bonaire is expanding largely due to the open landfill. This species predates on tern nests and should be controlled if it continues to expand in numbers.

All in all 18 trigger species occur in the nine IBAs in the Caribbean Netherlands. The IBAs on the Leeward islands of Saba and Sint Eustatius host ten and eleven species respectively. Saba is important for the breeding seabirds Audubon’s Shearwater and Red-billed Tropicbird, species with a high conservation priority. The Saba Coastline IBA is the only IBA in the Caribbean Netherlands that qualifies for Audubon’s Shearwater. Saba’s IBA qualifies for another seven species which are all year-round residents with a restricted world’s breeding distribution. St. Eustatius is important for the breeding seabird Red-billed Tropicbird, as well as another eight species: Bridled Quail-dove, hummingbirds and songbirds with a restricted range. The IBAs on the Leeward island of Bonaire host ten trigger species. Some of Bonaire’s IBAs are important for breeding seabird species with a high conservation priority like Royal, Sandwich, Common and Least Tern. Furthermore Bonaire’s IBAs are important for a number of species with a restricted range, of which Caribbean Coot and Yellow-shouldered Amazon have a high conservation priority.

Management Recommendations

On Bonaire several areas are identified that host IBA key species or other ecological valuable bird species and currently are not designated as IBA: 1) Ponds north of Dos Pos; 2) Ponds east of Kralendijk; 3) Urban parrot roosts; 4) Seru Largu. 


This report is part of the Wageningen University BO research program (BO-11-011.05-016) and was financed by the Ministry of Economic Affairs (EZ) under project number 4308701005.

Data type
Research report
Research and monitoring
Report number
Geographic location
St. Eustatius