Very sensitive to infrasound, certain migratory birds that frequent Polynesia, such as the kivi, are able to anticipate the arrival of storms or even waves linked to earthquakes. A team of scientists embarks aboard the Bougainville to find out if their movements can improve our own warning systems.
It was in the mind of an army officer, experienced in interventions in areas affected by cyclones or tsunamis, that the idea was born. What if birds could help us better anticipate these natural disasters? “We have been called upon to investigate the question”, explains Frédéric Jiguet, professor at the National Museum of Natural History, and head of the Kivi Kuaka program. A program that will launch its first expedition, in a few days at the fenua. Several months of preparatory studies confirmed that the idea was promising. Because scientists know that some migratory birds can rely on their sensitivity to infrasound. Imperceptible by humans, they allow them to pick up very early on the signs of potentially dangerous natural phenomena, for themselves and for humans.
“We have proven cases of small birds in the United States that leave their site to let a hurricane pass and come back after, explains the biologist and ornithologist. And then we have testimonies from survivors of the tsunami in Aceh, Indonesia, who say they saw flocks of birds entering the land several minutes before the arrival of the wave ”. Research has mainly focused on certain highly migratory species that “Are able to predict their departure based on winds and storms, and detect the presence of cyclones to bypass them”. This is particularly the case with the kivi, or Alaskan curlew, which connects North America to the Pacific Islands every year without stopping. Or the red barge – Kuaka in Maori – which can also travel up to 12,000 kilometers in one go. Birds which could, by their detection capacity, “Participate in early warning systems”, supports the researcher.
5 grams to follow the movements, from Tuamotu to Alaska
It remains to identify the movements of these birds. It is to this end that three researchers from the Museum, accompanied by specialists from the French Office for Biodiversity, the Bird Protection League, as well as a representative of the Polynesian Ornithological Society, will embark in Fakarava on board. of Bougainville. The French Navy’s multi-mission ship will help them reach 5 uninhabited atolls – for reasons of conservation, but also health security – of the Tuamotus. Tahanea, Haraiki, Reitoru, Tekokota, Tikei… On each island, the team will set net traps to immobilize the kivi, but also other migrants such as the torea (bald plover) and the uriri (errant knight). A total of 90 birds are expected to be equipped with ultralight GPS beacons.
State-of-the-art equipment, which offers itself its first large-scale test. These 5 gram Icarus beacons, which should also make it possible to collect data for Météo France, a partner of the mission, will communicate with the International Space Station every day. “If all goes well, we will be able to follow these birds for at least a year, both in Polynesia and when they are going to leave to nest in Alaska”, continues Frédéric Jiguet. Readings that will be particularly interesting in the event of a cyclone or earthquake. “We will be able to study their possible behavioral modifications: if the birds leave one island to go to the next, take off in flight or return to the interior of the atolls to take shelter, details the professor. What will be interesting is to be able to measure the anticipation in relation to the arrival of the catastrophic event on the site ”.
If these two weeks of expedition bring convincing results, it will be necessary, to arrive at alert mechanisms, to equip more birds, and to develop instruments for receiving data on certain atolls. The study could also be extended to other territories, in particular New Caledonia and New Zealand. Or to other birds, including non-migratory species. By the way, Kivi Kuaka should allow to deepen the knowledge of the ringed and marked birds.
The kivi, in particular, is very little known despite its classification on the IUCN red list of endangered species. The torea and the uriri, on the other hand, are not protected, and are even sometimes hunted, but are fragile species. “It is interesting to know that, through the development of technology and knowledge, it is birds that can have a protective interest for humans, remark the shipping manager. At the time of the sixth mass extinction, it also makes it possible to realize that any species is important, even if it will reveal itself later ”.