FILE PHOTO: Tourists stand outside in Plaza Mayor of Madrid, Spain September 2, 2018. REUTERS/Javier Barbancho/

MADRID (Reuters) - Madrid has begun planning for a cull of almost all the city’s population of thousands of Kramer and Monk parrots, invasive species that the city council says are a nuisance to human neighbours and a threat to public health.

More than 11,000 birds, or some 90% of the capital’s total population of the birds, will be culled under the programme, local government officials said on Thursday.

The cull, criticised by several animal rights groups, is due to begin in October and run for 23 months. It will aim to bring the bird numbers under control by destroying nests, removing eggs, and capturing both chicks and adults using nets and cages.

“The ethical euthanasia of the animals will be conducted using methods that do not contravene animal welfare norms,” Madrid’s environment department said.

The parrots’ numbers have increased by a third in the last three years and they built 4,400 nests across the city in 2019, according to the council, which has been ruled by a conservative-far right alliance since June.

The birds build large, heavy nests, which run the risk of dropping from trees and occasionally bring branches down with them, according to official documents.

Wildlife protection associations dispute the birds’ negative impact on local fauna and flora and question the council’s capture and extermination techniques. They have denounced any potential use of gas as cruel.

Spanish anti-animal cruelty party PACMA is one of several animal rights organisations decrying the move, first announced in October. A PACMA-backed petition demanding the process be halted has received 32,000 signatures to date.

The local government has allocated just under 3 million euros ($3.25 million) for the operation.