Should animals have the same rights as humans? A legal crusade to redefine personhood is raising profound questions about the links between animal and human kingdoms.
Elephant follows monkey to legal personhood
Glossary
Bronx - A district of New York City.
Nonhuman Rights Project - An animal rights organisation that aims to have at least some nonhuman animals declared persons. The nonprofit organisation has also filed habeas corpus petitions on behalf of chimpanzees, but they were rejected.
Solitary confinement - The UN considers solitary confinement of over 15 days a form of torture.
Person - To possess personhood is to hold certain rights and legal protections against cruel and unfair treatment.
Sentient - Able to perceive or feel things.
Chorongo monkey - Also known as the common woolly monkey, they live in packs of up to 70 individuals.
Seismic shift - A very sudden or dramatic change.
Primatologist - A scientist who specialises in the study of primates.
Cognition - The mental processes involved in gaining knowledge and understanding.