World’s smallest monkey gives birth to 15-gram twins in Devon

A small wildlife charity in South Devon has announced a major breeding success with the birth of two finger-sized Eastern Pygmy Marmosets, the world’s smallest monkey species.
The infants were born on Thursday 9th July 2026 to parents Pablo and Tumble. The double arrival marks the first time Shaldon Wildlife Trust has successfully bred Pygmy Marmosets in 11 years.

The romantic story behind the new arrivals came together quickly. Dad Pablo arrived at the zoo from Shepreth Wildlife Park in June 2025, while mom Tumble joined him from Dudley Zoo in January 2026. They hit off from the moment they met, the pair proved to be an instant match, welcoming twins just six months after being introduced.

At birth, Eastern Pygmy Marmoset infants weigh approximately 15 grams—roughly the weight of a single ping-pong ball.

In Eastern Pygmy Marmosets, fathers take on the primary caregiving duties. Pablo has proved to be an exemplary father, carrying the twin infants on his back as he navigates the habitat, only handing them over to mom Tumble for feeding.

“We are absolutely over the moon,” said Zak Showell, Director at Shaldon Wildlife Trust. “To have our first Eastern Pygmy Marmoset births since 2015 is a huge milestone for our team, but to see how quickly Pablo and Tumble bonded makes it even more special.

“At 19 days old, the twins are doing fantastically well. Dads do most of the heavy lifting in marmoset families, and Pablo is an experienced dad, having had several babies at his previous zoo. Visitors this summer will need a keen eye, but if you look closely at Pablo’s back, you’ll see two tiny furry faces peeking out over his shoulders!”

Native to the rainforests of the western Amazon Basin, Eastern Pygmy Marmosets, Cebuella niveiventris are famous for their miniature size, reaching just 12 to 15 centimeters in length as adults. Classed as vulnerable to extinction by the IUCN Red List, wild populations face growing threats from habitat loss and the illegal pet trade.

The new family can now be spotted in their indoor and outdoor habitats at Shaldon Wildlife Trust, where they are helping raise vital awareness for tropical rainforest conservation throughout the peak summer holiday season.