A female common marmoset was found abandoned on a London bus in Kensal Rise, north-west London, sparking concerns among animal welfare groups about the impact of recent legislation on primate ownership. The monkey, later named Oyster, was discovered inside a laundry bag placed in the bus’s luggage bay on a 302 route. A passenger first noticed the bag when it obstructed a mother’s stroller, prompting the bus driver to move it and reveal the distressed animal.

Oyster was reported to be dehydrated and stressed but physically healthy. She was taken to a Metroline depot before being handed over to the Royal Society for the Prevention of Cruelty to Animals (RSPCA). The animal is currently in the care of experienced keepers at a sanctuary equipped with specialist primate facilities, where she has reportedly settled well and is expected to be introduced to a male companion in the near future.

The incident occurred shortly after new licensing rules for primates came into effect in England in April. Under the legislation, anyone keeping primates must obtain a licence to ensure the animals are housed in suitable conditions, with noncompliance resulting in potentially unlimited fines or imprisonment. However, the RSPCA and other animal welfare experts have expressed concern that these new requirements may lead some owners to abandon their primates illegally.

Clare Drew, RSPCA London chief investigator, suggested that Oyster’s abandonment was “clearly intentional” and feared she might be the first of many similar cases. Drew noted that the monkey had not been microchipped, a legal requirement under the new rules. She urged owners who struggle to care for primates or cannot secure a licence to seek help from vets, charities, or specialists rather than resort to abandonment, which can have severe consequences for the animals.

Alison Cronin, director of Monkey World and a contributor to the primate licensing legislation, acknowledged that primate abandonment is not a new phenomenon but welcomed the law’s intent to regulate ownership more strictly. She pointed to widespread misconceptions fueled on social media about primates as suitable domestic pets and expressed hope that the new licensing system would reduce mistreatment by ensuring monkeys are only sold to appropriate homes.

Between 2021 and 2025, the RSPCA recorded 238 reports related to primate neglect and cruelty, highlighting ongoing welfare challenges. While a survey conducted earlier this year suggested limited initial uptake of the licensing scheme, experts have observed an increase in compliance as awareness grows.

The case of Oyster underscores the complexities involved in balancing animal welfare, owner responsibility, and regulatory enforcement as the government seeks to address the challenges posed by primate keeping in England. Investigations continue as authorities attempt to trace those responsible for the abandonment.