The small primate has since been named Oyster in honour of London's travel card
A female marmoset monkey has been rescued after being discovered abandoned on a London bus, concealed inside a laundry bag placed on the luggage rack.
The small primate, who has since been affectionately dubbed Oyster in honour of the Capital's travel card, was left on the 302 bus and found when the vehicle reached Kensal Rise in north-west London on Friday morning.
Her presence only came to light when a mother boarding with a pushchair was unable to pass through the aisle because the bag was jutting out from the luggage bay and obstructing the walkway.
The bus driver stepped in to assist the passenger and, upon shifting the bag, heard the animal chirping and leaping about inside.
When he peered inside the chequered plastic bag, he discovered the frightened marmoset trapped in a small metal bird cage.
She had been left with nothing more than a piece of apple and was found stressed and dehydrated.
The driver transported the animal to the Metroline depot in Willesden, where the RSPCA was called in.
Clare Dew, the charity's London Chief Inspector, said: "No-one noticed anything unusual on the bus before the monkey was discovered but we'll be looking at CCTV and logs for scanning on and off to see if we can locate the person who left her on board."
She added: "It was clearly intentional. This is clearly a direct result of the new legislation and is something we feared would happen. I'd be surprised if it's the last primate we see being dumped."
The RSPCA believes the incident is directly connected to primate licensing rules that came into force in England in April, requiring anyone keeping a primate as a pet to obtain a licence.
Evie Button, the charity's Exotic Animals Expert, said: "Primates are highly intelligent and social wild animals who need a lot of space, mental stimulation and appropriate companions - needs that can't be met by human company alone."
She described the licensing regime as "an important step forward for animal welfare" but warned: "There is a real concern that keepers who cannot or do not want to license their pet may now instead abandon them."
With the Government estimating that roughly 5,000 primates are currently kept as pets in England, and Born Free reporting minimal uptake of the new licence system, the charity fears many animals remain unaccounted for.
Oyster has since received a clean bill of health following a veterinary examination and been moved to an animal sanctuary, where carers plan to pair her with a male companion.
The RSPCA is urging anyone struggling to look after a primate or unable to secure the necessary licence not to resort to abandoning their animal.
Instead, keepers should contact a vet or reach out to animal welfare organisations for guidance on rehoming.
The investigation into who left Oyster on the bus continues, with officers reviewing CCTV footage and passenger records.
