Sunday, June 21, 2009
Bonaire’s Bats are Seriously Endangered by Increasing Construction
The cave-dwelling bat-colonies on Bonaire are under increasing pressure. The Barcadera and Colombia areas of Bonaire offer the highest diversity among bats on Bonaire, including the Mormoops megalophylla (phantom-face bat), a sub-species that is only found on Bonaire.
A large colony of Leptonycteris curasoae (long-snout bat) seems to have been driven away already. This is also the area for the Natalus tumidirostris (funnel-eared Bat). This animal is still found here, although it is possibly close to extinction on Bonaire. The increase of tourism, tourism projects, and construction of luxury villas threaten the survival of the cave-dwelling bats. It is estimated that 75% of cave-dwelling bat species on Bonaire have less than 500 individuals still living. Further, the fact that more and more people are visiting the caves does not help either in protecting these diminishing colonies.
These summations can be found in a 2008 report by Anna Rojer of the scientific institute for Caribbean Research and Management of Biodiversity (Carmabi) in Curaçao. STINAPA Bonaire was shocked by the results and sounded the alarm bell: both caves and bats urgently need protection.
In areas with many caves, like Barcadera, Santa Barbara, Colombia, and Lima, there is construction planned while there is a lack of consideration for the bats’ environment. By protecting the caves and the surrounding areas, the bat population may be saved. Carmabi has pledged support to STINAPA in developing a control plan.
In 1991, the Barcadera area was designated as a protected area due to the presence of these caves and their bats. Unfortunately the government lifted that protection in 2005 to allow construction. STINAPA is pleading to reinstate this protection before it’s too late. The same goes for the Colombia area, which is also rich in caves and cave-dwelling bats.
Many tropical bat-species need caves as a daytime hiding place. It is also the place where their young are born. Not every cave is suitable for the bats. Most species have specific requirements. It is known that the phantom-faced bat (Mormoops megalophylla) and long-snout bats (Leptonycteris curasoae) only will live in caves that are very warm, so bats cannot simply relocate to another cave when disturbed, as other caves may not necessarily meet their exact habitat requirements. The rare Natalus tumidirostris’ (funnel-eared bat) also has high demands for its living quarters. There are only about 100 to 150 specimens left on Bonaire. There used to be a large colony that lived in a cave in Sabadeco until it collapsed when a house was built on top of it.
It’s not only the actual destruction of their cave homes that will drive bats away, but an entire colony of phantom-faced bats was decimated in Curacao when construction took place hundreds of meters away. It is theorized that the vibrations or sounds of the scraping of the earth by the bulldozers caused the bats to leave their cave home.
The funnel-eared bat still exists, but in only one cave on Bonaire. Just entering the cave could mean the wholesale death of this species if they have young as the disturbance can cause the babies to drop to the ground and die of hunger.
Bats are the only indigenous mammal species on Bonaire and all species that do exist on Bonaire are endemic subspecies. This means that they only occur on the Leeward islands and nowhere else in the world. They are very useful to man and nature because they eat mosquitoes and cross-pollinate the cacti (see image above). The long-tongue bat (Glossophaga elongate) and the long-snout bat are nectar-eating bats that pollinate the flowers of the pillar cacti, which only bloom at night. This pollination allows the fruits to grow which provide food for birds and reptiles in the dry season. (Source: STINAPA, image courtesy of Ron van Rijn)
