An airborne reintroduction(giới thiệu lại) programme has helped conservationists(người bảo vệ môi trường) take significant steps to protect the endangered Galapagos tortoise.
A Forests of spiny cacti(xương rồng gai) cover much of the uneven(nhấp nhô) lava plains that separate the interior(nội địa) of the Galapagos island of Isabela from the Pacific Ocean. With its five distinct(riêng biệt) volcanoes, the island resembles(giống) a lunar landscape. Only the thick vegetation at the skirt of the often cloud-covered peak(đỉnh) of Sierra Negra offers respite(hoãn, nghỉ ngơi) from the barren(khô cằn) terrain(địa hình) below. This inhospitable(khắc nghiệt, không thuận lợi) environment is home to the giant Galapagos tortoise. Some time after the Galapagos’s birth, around five million years ago, the islands were colonised(thành thuộc địa) by one or more tortoises from mainland South America. As these ancestral(thuộc tổ tiên) tortoises settled(ổn định, định cư) on the individual islands, the different populations adapted to their unique environments, giving rise to at least 14 different subspecies(phân loài). Island life agreed with them. In the absence of significant predators(động vật ăn thịt), they grew to become the largest and longest-living tortoises on the planet, weighing more than 400 kilograms, occasionally exceeding(vượt quá) 1,8 metres in length and living for more than a century.
B Before human arrival, the archipelago’s(quần đảo) tortoises numbered in the hundreds of thousands. From the 17th century onwards, pirates(cướp biển) took a few on board for food, but the arrival of whaling ships in the 1790s saw this exploitation(sự khai thác) grow exponentially(theo hàm mũ). Relatively immobile(bất động) and capable(có khả năng) of surviving for months without food or water, the tortoises were taken on board these ships to act as food supplies during long ocean passages. Sometimes, their bodies were processed into high- grade oil.
In total, an estimated 200,000 animals were taken from the archipelago before the 20th century. This historical exploitation was then exacerbated(làm trầm trọng) when settlers came to the islands. They hunted the tortoises and destroyed their habitat to clear land for agriculture. They also introduced alien(ngoại, khác) species – ranging from cattle(gia súc), pigs, goats, rats and dogs to plants and ants – that either prey on the eggs and young tortoises or damage or destroy their habitat.
C Today, only 11 of the original subspecies survive and of these, several are highly endangered(gây nguy hiểm). In 1989, work began on a tortoise-breeding(sinh sản) centre just outside the town of Puerto Villamil on Isabela, dedicated(dành cho, hết mình cho) to protecting the island’s tortoise populations. The centre’s captive(nhốt)-breeding programme proved(cho thấy, chứng tỏ) to be extremely successful, and it eventually had to deal with an overpopulation(bùng nổ dân số) problem.
D The problem was also a pressing(cấp bách) one. Captive-bred tortoises can’t be reintroduced into the wild until they’re at least five years old and weigh at least 4,5 kilograms, at which point their size and weight – and their hardened shells(mai rùa) – are sufficient to protect them from predators. But if people wait too long after that point, the tortoises eventually become too large to transport.
E For years, repatriation(hồi hương, trở về nơi sinh ra) efforts were carried out in small numbers, with the tortoises carried on the backs of men over weeks of long, treacherous(không chắn chắn) hikes along narrow trails(đường mòn). But in November 2010, the environmentalist and Galapagos National Park liaison officer(sĩ quan liên lạc) Godfrey Merlin, a visiting private motor yacht(thuyền buồm) captain and a helicopter pilot gathered(tập hợp) around a table in a small cafe in Puerto Ayora on the island of Santa Cruz to work out more ambitious(tham vọng) reintroduction. The aim was to use a helicopter to move 300 of the breeding centre’s tortoises to various locations close to Sierra Negra.
F This unprecedented(chưa từng có) effort was made possible by the owners of the 67-metre yacht White Cloud, who provided the Galapagos National Park with free use of their helicopter and its experienced pilot, as well as the logistical(hậu cần) support of the yacht, its captain and crew(đoàn thủy thủ). Originally an air ambulance(xe cứu thương), the yacht’s helicopter has a rear(phía sau) double door and a large internal space that’s well suited for cargo(hàng hóa), so a custom crate(sọt, thùng thưa) was designed to hold up to 33 tortoises with a total weight of about 150 kilograms. This weight, together with that of the fuel(nhiên liệu), pilot and four crew, approached(gần bằng) the helicopter’s maximum payload(trọng tải), and there were times when it was clearly right on the edge of the helicopter’s capabilities(khả năng). During a period of three days, a group of volunteers from the breeding centre worked around the clock to prepare the young tortoises for transport. Meanwhile, park wardens(người bảo vệ), dropped off(đưa đến) ahead of time in remote locations, cleared landing sites within the thick brush(bụi cây), cacti and lava rocks.
G Upon their release(thả, phóng thích), the juvenile(thiếu niên, non) tortoises quickly spread out over their ancestral territory, investigating(thăm dò, điều tra) their new surroundings and feeding on the vegetation. Eventually, one tiny tortoise came across a fully grown giant who had been lumbering(nằm ngổn ngang) around the island for around a hundred years. The two stood side by side, a powerful symbol of the regeneration(sự hồi sinh) of an ancient species.