Our folly with regard to animals knows few bounds. These days it tends towards the sentimental. We support sanctuaries where donkeys are pampered and where swans can have their broken wings mended. We lavish money on the RSPB and on the cats that eat the birds that the RSPB protects. The Scottish Wildlife Trust has organised a preposterous venture to re-establish beavers in the wild. On Salisbury Plain a well-meaning charity receives €2.2 million from the EU to release great bustards flown in from Russia, only for their eggs to be eaten by foxes. We fall over ourselves to save whales and show our hatred of faraway hunters who dare to club the loveable seal, but we scarcely raise an eyebrow over the atrocious suffering endured by chickens and pigs so that we may enjoy cheap meat.

In various parts of the world conservationists are waging war to contain the effects of past stupidity and carelessness, and it is this conflict that has given William Stolzenburg the subject for an absorbing, if rather irritatingly written, book. His arena is the world’s offshore islands, each of which once consisted of a unique and wondrous ecosystem whose delicate balance was irreparably upset as soon as we turned up.

The ruin started early. Hawaii was, in Stolzenburg’s words, a ‘paradoxical kingdom of grounded birds’ until the Polynesians paddled in around AD 600. The humans ate the plumper specimens and the rats they brought with them tucked into the rest. Around six centuries later Maoris reached New Zealand to be met by more than a dozen species of nourishing wingless birds, including that ‘walking bonanza of bird meat’, the mighty moa. It took no more than a century to polish off the moas, after which the hunters turned on a big, green, toothsome, defenceless parrot called the kakapo.

Some time later, courtesy of Captain Cook, the brown rat arrived in New Zealand, accompanied by the ship’s cat and followed by the rabbit. The rabbits ate the grass, the rats everything else. In the 1880s the harassed administrators authorised the introduction of weasels and stoats. These were supposed to eat the rabbits, but in Stolzenburg’s droll phrase ‘they also came with brains’ and ate the birds instead.

Stolzenburg’s heroes are the men who made it their mission to save the defenceless from the invaders. An early example, Richard Henry, spent years rounding up kakapos from the New Zealand mainland and installing them on Resolution Island. He thought the mile of water would keep the enemy out. One day he spotted a weasel on the shore and knew the game was up.

Across the world, in the Bering Sea off Alaska, a similar saga was being played out. Arctic foxes had been shipped to various of the Aleutian Islands so that their pelts could be harvested. When the bottom fell out of the fur market the animals were abandoned to their own devices – chief of which was to eat the birds that nested in phenomenal abundance, particularly the big, juicy, cackling goose. A man called Bob Jones – nicknamed ‘Sea Otter’ – went through the islands poisoning, trapping and shooting the foxes. But even Sea Otter was confounded by the rat.

‘Supernatural escape artist and ecological wrecking ball’ is how Stolzenburg characterises Rattus norvegicus. It was not until the development in the 1970s of a new super-poison, brodifacoum, that the rats’ enemies at last acquired the weapon they had, up until then, dreamed of. New Zealand biologists spread it across an island called Breaksea and cleared it of rats in three weeks. ‘Breaksea reconfigured the horizons,’ Stolzenburg comments with relish. Another rat stronghold, Campbell Island, was bombarded by helicopters with 120 tons of poison, and 200,000 rats perished.

American conservationists were inspired. They laid siege to Rat Island in the Aleutians, where the speciality of the brown rats was to snap a hole in the skulls of nesting auklets and suck out their brains. Forty-six tons of brodifacoum put an end to the feasting.

Stolzenburg drops in on other theatres of war: Baja, in the Sea of Cortez, where five islands were cleared by assorted means of cats, rats, rabbits and burros; Anacapa, off California, where the exterminators stood up to protestors upholding the rights of rats; and Santa Cruz, another Californian island, where a horde of feral pigs was pursued and massacred until the last grunt was heard. He is an energetic exponent of the hectic, adjective-laden school of journalistic non-fiction. Winter in the Aleutians Islands is not just winter, but ‘the long raging siege of winter’. Campaigners are ‘conservationistas’; one of them is ‘the unassuming sage of laconic wit, the Yoda of the car wars’.

Fortunately there is not too much of this. The book is refreshingly short, Stolzenburg having had the sense to realise that one slaughter is much like another. Nor, pleasingly, does he trouble himself with sympathy for the victims of the conflict. Like the rest of us he can admire the lethal efficiency of the rat and its fellow assassins, while still being of the view that the best rat is a dead one.