IELTS Academic Reading Practice Test 7: Passage 1

The kakapo is, by almost any standard, an unusual parrot. It cannot fly, it is active mainly at night, and at up to four kilograms for a well-fed male, it is the heaviest parrot in the world. It is also thought to be one of the longest-lived birds, with some individuals possibly reaching sixty years or more. Its moss-green feathers, flecked with yellow and black, provide excellent camouflage on the forest floor, and when it senses danger, its instinct is to freeze and remain perfectly still. For most of its history this was an effective defence. Before humans arrived, the only land mammals in New Zealand were bats, and the kakapo's main enemies were birds of prey, which hunted by sight.

The arrival of people changed everything. Polynesian settlers, the ancestors of the Māori, hunted kakapo for food and used their feathers to make cloaks, and they brought with them dogs and the Pacific rat. European settlement in the nineteenth century brought further losses: large areas of forest were cleared, and cats, rats and stoats were introduced. Unlike birds of prey, these mammals hunt mainly by smell, and the kakapo, which has a strong, musty odour, was easy to find. Standing still, its best defence against eagles, became its worst response to a stoat. Breeding females were especially vulnerable, because they raise their chicks alone and must leave the nest each night to feed.

Concern about the bird's decline is not new. In the 1890s, a caretaker named Richard Henry moved hundreds of kakapo by boat to Resolution Island in Fiordland, which was then free of predators. For a few years the plan seemed to be working, but around 1900 stoats reached the island, probably by swimming from the mainland, and the birds there were soon gone. By the middle of the twentieth century the kakapo had vanished from most of its former range, and searches in the remote valleys of Fiordland in the 1970s found only a few birds, all of them male. The species seemed doomed until 1977, when a previously unknown population was discovered in the south of Stewart Island. Crucially, this group included females. Yet even here, feral cats were killing the birds at an alarming rate.

During the 1980s and early 1990s, all the surviving birds that could be found were moved to offshore islands from which predators had been removed. Even so, numbers continued to fall, and in 1995, when a new national recovery programme began, the entire species consisted of just 51 birds. The programme's approach has been one of extraordinarily close management. Every kakapo has a name, and each carries a small radio transmitter which allows rangers to find it and, in recent versions, to record when and with which partner it has mated. Birds are given extra food to encourage breeding, and nests are watched day and night by cameras. When a female leaves her nest to feed, rangers may cover the eggs or chicks with a heated pad to keep them warm; eggs at risk may be taken away to be incubated artificially, and weak chicks are raised by hand.

Breeding remains the greatest difficulty. Kakapo do not breed every year; instead, they breed only when certain trees, especially the rimu, produce an unusually heavy crop of fruit, which happens only every two to four years. In breeding seasons, males gather at traditional display grounds, where each digs a shallow bowl in the earth and spends the night producing a deep booming call by inflating air sacs in its chest. The sound, which can travel several kilometres, attracts females, which may walk a long way to choose a mate. Even when mating occurs, many eggs fail to hatch. Because all of today's birds are descended from so few ancestors, the population has very low genetic diversity, and scientists believe this contributes to the high rate of infertility. To address this, the team has used artificial insemination and has sequenced the genome of almost every living kakapo, so that pairings can be planned to keep as much variety as possible.

These efforts have been rewarded. In 2019, an exceptional rimu crop produced the most successful breeding season on record, and the population rose above two hundred for the first time in decades, despite an outbreak of a fungal disease that killed several birds. In 2023, a small number of kakapo were released into a fenced sanctuary on the North Island, the first time in decades that the species had lived on the mainland. The kakapo remains critically endangered, and every bird is still monitored closely. But a species that was once reduced to a few dozen individuals now has a real chance of survival.