Networking geckos a in tropical forest.
Research site: Praslin Island, Seychelles
What?► The question is whether ecological interactions among species – including humans – could threaten the fragile ecosystems and biodiversity in the tropical forests of the Vallée de Mai on island of Praslin, a UNESCO World Heritage Site in the Seychelles.
A major concern is the endangered coco de mer palm, Lodoicea maldivica, which produces a massive, talismanic fruit that looks like a double coconut. The fruit grows only on two islands in the Seychelles and is poached as an aphrodisiac; its loss would be a major biodiversity hit for the islands. The species has separate male and female trees, and scientists are trying to establish which creatures are its chief pollinators. “Something is transporting the pollen from tree to tree using bridges in the forest canopy and we want to know what that is,” says Christopher Kaiser-Bunbury, a network ecology expert at the Technical University of Darmstadt who researches the issues with his wife, Seychelles science program coordinator Nancy Bunbury. The aim is to see what combinations of insects, birds and animals most effect pollination – and mapping that in the form of mathematical network interactions.
How?►The researchers work in the tropical forests of the Seychelles for eight months of the year. It can be gruelling fieldwork with temperatures peaking above 50 degrees Celsius, but with sudden three-hour tropical storms just as likely to leave them soaked and cold, he says. “I can lose 12 kg in a season and I am not a particularly big guy anyway,” Kaiser- Bunbury says. “It’s a lot of full-blast mountain work, day and night, and extremely strenuous.” Keeping hydrated, and with salty snacks at hand, is important. In addition to field ecology, however, the pair have also been testing some advanced ecotech.
Since one suspected coco de mer pollinator is the 30-cm-long giant gecko, the pair tested intelligent GPS radio tags developed by Microsoft Research to track it. These tags connect with each other to form a mesh network that relays messages through a chain of geckos, so researchers need to access only one critter’s tag to download data from many of them.
The tags are too heavy, however. “The 18-gram GPS tags need to be shrunk. The battery is the main issue,” says Kaiser-Bunbury. Next, he says, he would like to use drones to observe the Seychelles’ saltwater manatees, called dugongs. The noise of boats scares the dugongs away, so drones are ideal observation platforms as they are quiet at altitude. That will allow the researchers to check on dugong numbers, feeding habits and risks like the choking threat from the plastic micropollution caught up in the Indian Ocean’s swirling “gyre” current.
Special report by Paul Marks