Malpais is a former plantation, just north of Sint Michiels Bay. An earthen dam has been erected, thus creating two lakes, that retain at least some water during dry seasons in most but not all years. The IBA, that is the two lakes and their near surroundings, covers an area of c. 3 km2 from about 10 to 71 m asl. Greater Malpais is about twice the size of the IBA. [this IBA should include the surrounding area in my opinion to encompass some important dry scrub habitat and its associated bird species and to include the vegetation and waterhole below the dam which hosts a large and important Brown-throated Parakeet roost and a columbid roost that includes Scaly-naped and Bare-eyed Pigeons.
The area is managed as part of a conservation area and has excellent well-signed and designated hiking trails which are maintained by the local conservation organization Uniek Curaçao. Unfortunately, the island’s large and apparently growing dumpsite is located just north and upstream of the Malpais freshwater ponds. The potential of contamination of the wetlands from toxins leaching from the dumpsite and from the adjacent pig farm is unknown.
St Michael Lagoon (500 ha. 0 – 50 m altitude) is situated on the south coast of Curaçao some 5 km north-west of Willemstad and forms part of the greater Malpais conservation area. It is landlocked, lying inland from the coral reef-fringed St Michiels Bay. The area is basically basaltic in origin with overcapping hills of coralline limestone rock surrounding the lagoon.
Caribbean Coot Fulica caribaea is a regular at Malpais, with normally tens of birds observed at a time (46 in March 2000) but frequently numbering upwards of 100 (Debrot, pers. observ.). It is present all-year round in most years, and has been confirmed breeding. Other probable or confirmed breeding birds include White-cheeked Pintail, Common Moorhen, Black-necked Stilt, Pied-billed Grebe, Least Grebe Tachybaptus dominicus and Black-crowned Night-Heron Nycticorax nycticorax. Wintering waterbirds include Blue-winged Teal and the occasional other duck species.
The area below the dam is a traditional roost for Brown-throated Parakeets and columbids. As many as 165 Brown-throated Parakeets were counted leaving the roost in early morning in November 2003 (Wells pers. obs.). The surrounding habitat supports characteristic thorn scrub bird species including White-tailed Hawk, Crested Caracara (20 in Nov., 2003), American Kestrel, Crested Bobwhite, Bare-eyed Pigeon (an exceptional 600 leaving roost in April 2000), Ruby-topaz Hummingbird, Blue-tailed Emerald, Caribbean Elainia, Northern Scrub-Flycatcher, Black-whiskered Vireo, Rufous-collared Sparrow, Troupial, and Yellow Oriole.
The wetlands and surrounding vegetation, imbedded within the otherwise dry habitat of the island, are a magnet for migrating birds. Feeding groups of migrating Caribbean Martins were observed in Nov., 2003, and are likely regular. Species like Blackpoll Warbler and Northern Waterthrush are of regular occurrence and the site has hosted many rarer and irregular species including Philadelphia Vireo, Red-eyed Vireo, Chestnut-sided Warbler, Northern Parula, and Ovenbird. Wintering raptors that have been regularly observed here include Peregrine Falcon and Merlin.
The prime importance of this site are the waterbirds that are supported by the freshwater dam. Most waterbirds are non-breeding species, and these include a number of herons and shorebirds. The flamingos that feed in the freshwater dam and nearby saline lagoon are part of a population of flamingos that variously use the three main saline wetlands of Curacao. Thus the Malpais area forms part of a vital network that supports an important southern Caribbean population of the species.
St Michiel Lagoon
Greater Flamingo 100-200 throughout the year (157 counted March 2000, 81 Nov., 2003—Wells pers. obs.) Common Tern (15 pairs breeding in 2002 and a similar level of breeding confirmed for 2006 (A. Debrot, pers. obs.)
Other species documented include Reddish Egret, White-cheeked Pintail (25 in Nov., 2003), Peregrine Falcon, Merlin, Osprey, Black-necked Stilt (30-Nov., 2003), Greater Yellowlegs, Lesser Yellowlegs (50 in Nov., 2003), Willet, Western Sandpiper, Least Sandpiper.
Non-bird biodiversity: Floristically the area is important as a number of endemic plants are present (Anonymous 1989). Apart from Christoffel National Park, Malpais is the only other area on Curaçao where the White-tailed Deer Oidocoleus virginianus is found. The endemic freshwater fish Poecilia vandepolli is present in the lakes (Vonk et al. 2007; Debrot, 2003). The area supports several or possibly all of the seven bat species known to occur on Curaçao as well as various lizard and endemic landsnail species.
Pressure/threats to key biodiversity
The island’s large and apparently growing dumpsite is located just north and seemingly upstream of the Malpais ponds, as is a pig farm, the smell of which can be almost overpowering at times. The potential of contamination of the wetlands from toxins leaching from the dumpsite and pig farm is unknown. While hunting and poaching of parakeet nests appears to be limited, uncontrolled recreational access by hikers who bring along dogs is a threat to both birds and other fauna such as the white-tailed deer.
Poor maintenance of the dam may result in the desiccation of one of the two freshwater lakes during prolonged dry seasons, thus significantly decreasing the value of the area for waterbirds and the endemic fish.
The main threat to St. Michiel is uncontrolled public access that disturbs the flamingos and limits their presence. The nesting terns are located on the distant west side of the lagoon, away from the most intensive recreational disturbance.
Conservation responses/actions for key biodiversity
Relatively extensive research has been conducted by staff and visiting scientists of the Carmabi Foundation in the past decades. CARMABI has for instance done surveys on both the vegetation and the White-tailed Deer Oidocoleus virginianus that inhabit the area as well as butterflies and the rare endemic Curaçao Barn Owl which nest in the limestone cliffs. Inventories of waterbirds and terrestrial birds, as well as fishes, has been carried out by the Zoological Museum Amsterdam (2006). The area has been recognized as an key bird area for many years already (e.g. Bokma 1972, Debrot and de Freitas 1991).
Habitat and land use
The avifaunal diversity of the area of the Malpais area has long been known (e.g. Bokma 1972) and can be ascribed to the diversity of habitat types in combination with low disturbance levels. The freshwater dam is one of the island’s two most important and rare freshwater bird sites (Debrot and de Freitas 1991). Aquatic vegetation found here include the uncommon Ammania coccinea, Echinodorus berteroi and Nymphaea ampla. More towards the coast lies the hypersaline lagoon habitat of the salina of Sint Michiel. This saline lagoon constitutes one of the three principal foraging areas for the flamingo on Curacao, as well as important nesting habitat for the Common Tern. The area further possesses both coralline limestone and volcanic geological formations. In general, the dry deciduous vegetations of volcanic soils on the island have been more seriously impacted by agriculture and urbanization, than have the evergreen limestone vegetations. In the Malpais area, the dry deciduous vegetations are nevertheless in very good condition and harbor many rare plant species such as Abrus precatorius, Crateva tapia, Geoffroea spinosa, Senna bicapsularis and others. The calcareous plateau vegetation of Malpais is of the Coccoloba swartzii-Erithal fruticosa type, which is only found in the central part of the island. Malpais contains the largest patch of this vegetation with such species as Crossopetalum rhacoma, Erithalis fruticosa, Guiacum sanctum and Metopium brownei (Beers et al. 1997). Below the dam, the wetter soils have contributed to the growth of a thicker, more luxuriant forest (“Hippomane Rooi vegetation”) interspersed with some larger non-native fruit trees apparently a legacy of the former plantation.
BirdLife International (2020) Important Bird Areas factsheet: Malpais-St Michiel. Downloaded from
http://www.birdlife.org on 08/08/2020.