Flamingo, the pink pigeon who was rescued from Madison Square Park, died overnight.

Rescuers believe his death was a reaction to hair dye, which they suspect was the cause of his pink hue.

The Wild Bird Fund, which had been caring for Flamingo, announced its death in a Twitter post on Tuesday:

“We are deeply sad to report that Flamingo, our sweet pink pigeon, has passed away,” the group said. “Despite our best efforts to reduce the fumes coming off the dye, while keeping him calm and stable, he died in the night.”

The Wild Bird Fund said that the pigeon's death was likely due to inhaling the chemicals from the dye.

Rita McMahon, the director of the Wild Bird Fund, told Gothamist last week that her team did not know who colored the bird pink, or why, but they believed Flamingo had been used as a prop in a gender reveal party.

She said the bird still smelled of perfume, days after it had been rescued.

Flamingo was rescued last week by Carlos Rodriguez, a professional dog walker who spotted the pigeon in Madison Square Park.

He took Flamingo uptown to the Wild Bird Fund in a taxi.

Since then, the pigeon had been in “delicate critical” condition, vomiting repeatedly. McMahon believed the bird had been ingesting the dye’s chemicals through preening, which birds spend about a third of their day doing.

On Tuesday morning, the Wild Bird Fund also thanked people for their interest in Flamingo.

“Flamingo's story sparked a lot of emotion and generated interest from around the world," the Wild Bird Fund wrote on Twitter. "We hope the tale of his too-short life will help prevent more acts of careless cruelty.”