A British duke sent six Himalayan tahr to New Zealand in 1904; five survived the voyage, and their descendants later grew into tens of thousands that now damage fragile alpine ecosystems

The Himalayan tahr is a large, shaggy mountain ungulate native to the Himalayas that has become an invasive species in New Zealand. In 1904, a gift from a British aristocrat brought a handful of shaggy mountain goats to the remote peaks of New Zealand’s South Island. The aim was to build up big game stocks […]

In 1867, Canterbury released 40 house sparrows to eat crop pests; within 15 years New Zealand was poisoning the birds and paying bounties after they began stripping grain crops

The Canterbury Acclimatisation Society liberated 40 sparrows in 1867. (Picture: Birds of the world) The house sparrow was brought to New Zealand in 1867 to help farmers deal with crop-eating insects, but the small bird soon became a problem of its own. Within a few years, while it grew in numbers, it also began damaging […]

In the 1930s, Florida introduced rhesus macaques to boost tourism; today the invasive monkeys carry a potentially fatal virus and are considered a public-health concern

Nonhuman primates (NHPs) can harbour multiple zoonotic pathogens owing to their close phylogenetic relationship and frequent interactions with humans. They can also be extremely successful ecological invaders. Within the United States, fewer than or equal to NHP species have been introduced and of them, the rhesus macaque has successfully established populations in Florida and Puerto […]

19th-century ships accidentally brought mice to islands 30 miles off San Francisco; they later reached densities of 1,270 per hectare and began reshaping the seabird ecosystem

The Farallon Islands Are Off Limits to Humans — but Not Wildlife Accidentally brought to the Farallon Islands by ships in the 19th century, non-native house mice have reached extremely high numbers, with densities of up to 1,270 mice per hectare. The rodents are disrupting the fragile ecosystem of the islands, located about 30 miles […]