Monk parakeets, which have established colonies in the home counties, are to be culled because they are alleged to pose a danger to crops, the electricity grid and native species.

The Department for Environment, Food and Rural Affairs is launching an eradication programme targeting the south American birds that first began breeding in the wild near Borehamwood, Hertfordshire in the mid-1990s.

Also known as the quaker parakeet, its raucous screech normally echoes through the subtropical forests and grasslands of Bolivia and southern Brazil. The birds' habit of building enormous communal nests does, however, cause problems.

In the United States, escaped birds have settled on electricity substations and power lines, causing blackouts when nests become sodden with rain. In some states – including California, Georgia and New Jersey – ownership, let alone release, of the species is banned.

The UK population is thought to number only 100-150 birds. With its green back, pale grey chest, pale orange beak and blue wing feathers, the monk parakeet, which grows to around 30cm in length, is a distinctive addition to the UK's wildlife.

At least three other parakeet species have established feral breeding colonies: the most numerous is the ring-necked parakeet, now common in many London parks and suburbs. Alexandrine parakeets, originally from Asia, and blue-crowned conures, from Venezuela, have also been observed nesting in eastern England.

Two years ago, Natural England designated ring-necked and monk parakeets as pests, enabling them to be shot without a licence. At the time there was an outcry of racism towards non-native species; the London Wildlife Trust said the ring-necked variety was "as British as curry".

Defra has now initiated an extermination programme against monks as a preventative measure. "Control work is being carried out as part of a Defra initiative to counter the potential threat monk parakeets pose to critical national infrastructure, crops and native British wildlife," a departmental spokesman said.

"This invasive species has caused significant damage in other countries through nesting and feeding activity and we are taking action now to prevent this happening in the UK."

The spokesman added: "We want to get rid of the wild population. There will be trapping, rehoming in aviaries and we will probably have to shoot some as well. Non-native, invasive species deprive the British economy of £1.7bn every year."

The Royal Society for the Protection of Birds backs Defra's cull. A spokesperson said: "These species aren't causing any major conservation problems in the UK at the moment, but they might in future."

But Andrew Tyler, the director of Animal Aid, said: "Branding other species as vermin or intruders is intolerant and selfish. The danger is overstated. We should stop the importation of these birds which are sold as commodities and endure lives of boredom in cages.

"It's not surprising they want to escape. If we are serious about coexisting with other species, we have to concede them territory."

• This article was amended on 26 April 2011. In the original, a sub-heading said that the monk parakeets themselves took a £1.7bn toll on the British economy. This has been corrected.