Hong Kong people were in a flap when they spotted a few pigeons in Victoria Park sporting suspicious looking red sticks on their tails, but an expert allayed their concerns, saying the attachments were simply whistles.

Pigeon racing expert Leung Kam-hung told Apple Daily that the suspicious looking red sticks objects were whistles, which helped alert owners that their birds had return home from a long distance flight. The whistles created a buzzing sound as the birds flew.

Leung said these pigeons might have been set free by their owners after the government began reducing the number of licenses allowing people to raise pigeons following the bird flu outbreaks that flare up in the city.

Officers from the Society for the Prevention of Cruelty to Animals (SPCA) said the whistles would be a burden to pigeons, and affect their mobility and flexibility.

SPCA officers made on-site observations, but failed to capture the pigeons with whistles for further examination. It said it would try to remove the whistles from the affected birds later.

Pigeon racing was once popular in Hong Kong and Taiwan, but its appeal has since declined due to the bird flu virus and controversies over illegal betting in the sport.

In 2013, People for the Ethical Treatment of Animals (Peta) from the United States found that around one million pigeons died in long distance races every year in Taiwan.