Happy, the Bronx Zoo's 55-year-old Asian elephant at the center of a groundbreaking animal rights case, was euthanized Tuesday following declining kidney and liver function. Zoo officials said her age-related conditions had progressed despite hospice care, ending years of legal battles over her confinement.

The Nonhuman Rights Project had sued for Happy's transfer to an elephant sanctuary, arguing she deserved habeas corpus protections as a cognitively complex being. New York's highest court rejected the case 5-to-2 in 2020, marking the first such animal rights appeal to reach that level in the English-speaking world.

Zoo officials called the lawsuit frivolous and maintained Happy received excellent care during her nearly 50 years at the facility. Her cognitive abilities first gained attention in 2005 when she became the first elephant to pass the mirror self-recognition test, demonstrating self-awareness previously documented only in humans, apes, and dolphins.

The case's dismissal sets precedent for how courts handle animal rights claims, potentially affecting zoo operations and animal sanctuary movements nationwide. While the Nonhuman Rights Project failed to secure Happy's freedom, the organization noted two dissenting judges supported her right to liberty, keeping the debate alive for future cases.