Many people were appalled when the Baby singer posted a shot of himself petting a chained tiger at his dad's engagement party over the weekend (30Apr16) on Instagram, and now a petition has been launched urging the singer to publicly apologise for his actions and make a big cash splash to the World Wildlife Fund to help officials in their efforts to double the tiger population by 2022.

The Care2 petition garnered over 2,200 signatures in less than two and a half hours, and by press time that figure had sailed past 21,000 supporters.

"My hope is that Justin Bieber just didn't know how awful animals like this tiger are treated and that once we alert him to it, he will do the right thing and apologize as well as donate to conservation efforts," Kelsey Bourgeois, the Care2 petition author, writes.

She notes the tiger is owned by the Bowmanville Zoo in Ontario, Canada, and that the big cat's trainer, Michael Hackenberger, has been charged with five counts of animal abuse. The petition also accuses Bieber and his family of perpetuating the abusive animal entertainment industry by hiring animals for events.

"Justin does not have a very good track record with animals," Bourgeois adds. "In 2013, he adopted a pet monkey and then abandoned it in Germany. Before that he bought a puppy at a shop rather than adopting from a shelter and gave away a pet hamster to a fan without warning. The hamster died in less than a year.

"This new picture with a captive tiger is yet another wrongdoing, and it's time to demand an apology and a public show of support for animal welfare."

Activists at People for the Ethical Treatment of Animals have also taken aim at Bieber for posing with the Bengal tiger, writing: "Justin Bieber is lucky not to have had his throat torn out by this stressed captive tiger. Tigers used for photo ops are torn away from their mothers shortly after birth, and the Bowmanville Zoo, in particular, was caught whipping one tiger more than 17 times, even after the cat was lying on his back in a position of submission and fear."

PETA bosses have asked Bieber to vow that he will never again promote "these types of abusive outfits".