LONDON — A British zoo says an endangered monkey that accidentally fell into a pond was eaten by otters.

Bristol Zoo Gardens say the rare golden lion tamarin monkey, a squirrel-sized species native to Brazil, was climbing on a branch when it fell and became trapped in the otter enclosure last month. The zoo said staff arrived too late to intervene.

The zoo made the statement after a whistleblower disclosed a series of animal deaths at the institution, including an endangered Visayan warty piglet that was eaten by its father shortly after it was born in December. The zoo said the male pig, Elvis, also attacked and killed the piglet's mother.

The zoo's director of conservation Christoph Schwitzer said despite their best efforts, keepers are unable to prevent unforeseen accidents.