Animal rights activists have urged Pope Francis to end the tradition of releasing doves, after two of the birds were attacked by predators on Sunday.

The pontiff and children flanking him set free two white doves from his studio window overlooking St. Peter's Square on Sunday. The birds were soon attacked by a crow and seagull.

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Animal rights activists claim domesticated doves cannot survive in the wild.

"Domesticated doves are easy targets for other birds due to their white color and inability to recognize predators and flee," writes Chris Wolverton on the petition website Care2.com. The online petition is asking to pope to stop releasing doves.

"The Pope's intentions in releasing the doves were innocent, but after witnessing the gruesome aftermath he needs to end the practice," the petition says.

"It was very disturbing to see those peace doves getting attacked," Wolverton said, according to FoxNews.com. "There are many other symbols he could use like paper cranes, white poppy flowers, and the peace sign, to name a few. Putting animals in danger is not a sensible way to promote peace."

Pro-animal advocate and ex-tourism minister Michela Brambilla told The Associated Press she was confident that Francis, with his "extraordinary love" for all creatures, would reconsider. At his election last year, Francis became the first pontiff to choose the name of St. Francis of Assisi, famed for his love for birds and other creatures of the wild.

"It is clear that traditions of many years reach a moment where they have to be reconsidered," Brambilla said in a telephone interview.

The National Animal Protection Agency published an open letter Monday reminding Francis that domesticated doves are easy prey for predators like gulls, who nest atop the colonnade of St. Peter's Square and scavenge for garbage in Rome. The group said freeing doves in Rome is like "condemning them to certain death."

An umbrella group of animal rights advocates, the Italian Federation of Animal and Environment Rights Associations, carried a text of the letter on its website.

Pope Francis seemed to have made up with the world of birds on Wednesday.

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Francis gladly blessed and held a green parrot named Amore on Wednesday that was offered to him by his owner, Francesco Lombardi.

Francis initially drove by Amore during his general audience, but then doubled back and took the bird for a few seconds on his finger. Lombardi said Amore parroted back the "Papa" that the crowd was chanting.

Information from The Associated Press was used in this report.