Prince Charles spoke up for a cause close to his heart during his latest royal engagement in Sandringham! As Hello! reports, Charles helped conservationists release the critically endangered Eurasian curlew on Tuesday, speaking about the importance of doing so.

Prince Charles says he's "delighted" to have assisted in curlew release

Prince Charles wore a light blue collared shirt, khaki pants, sunglasses, and patterned belt for the occasion. He was joined by Chrissie Kelley, Pensthorpe Conservation Trust's Head of Species Management, and Tony Juniper, chair of governmental advisory Natural England. As Hello! mentions, the conservation group has led an initiative to repopulate east England with the birds.

"I have always cherished the evocative call of the curlew, but it is now dangerously close to being something that our grandchildren will never have the chance to enjoy," Charles said. Charles went on to talk about how he's "particularly delighted" to be able to aid in the release of the curlews, thanking the "tireless work" of everyone involved.

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"Every curlew nest is something to prize, nurture and protect," the royal said, calling it "utterly vital" that people work together in order to do so. Charles is well-known for his environmental advocacy work. In January, he virtually shared a bilingual message about conservation at the One Planet Summit. Several other royals— including Prince William and Princess Charlene of Monaco— have also been strong proponents of conservation.