By Robert Fuller

The story of how I hand-reared a baby weasel touched the hearts of millions after a nature documentary featuring this tiny creature made it to American TV screens last week.

Initially shown on UK screens last October, the BBC programme aimed to dispel idea that weasels are villainous creatures. Sure enough, as the tale of how I adopted Twiz unfolded, viewers reached out via social media in their thousands to assert a newly discovered love for mustelids.

It was an incredible feeling to share my passion for these much misunderstood mammals. I follow the lives of wild weasels via hidden cameras in my garden and have long felt they don't deserve their poor reputation.

Given their size - weasels are the smallest carnivore in the world and can fit through a wedding ring - they are admirably tenacious creatures. Over years of studying and painting them, I have become increasingly knowledgeable about their behaviour and have raised and released several back into the wild. So when Twiz was found at just two weeks old, she was referred on to me.

But I was at a loss how to help a weasel as young as she was. At just 10.6g, she was impossibly small. Blind and deaf, she squirmed around in the palm of my hand with her head wobbling and squeaking in distress. A fine coat of blonde fur barely covered her pink body. At this age baby weasels, known colloquially as ‘fingerlings’, are roughly the size of a child’s finger. I contacted a local rehabilitation centre highly skilled at raising small mammals and asked them to take care of Twiz during this crucial early stage. Twiz was fed via a syringe every hour during the day and every two hours at night - an incubator was placed by her bedside so she could be fed every time she squeaked.

Feeding a kit as young as Twiz requires considerable skill. A drop of milk on the lungs could drown her.The first few days were critical but within two weeks Twiz had doubled her weight and had begun eating meat. She was returned to me and, at just over a month old, her eyes opened and she was running around.

By now Twiz was also eating dead mice. Instead of just placing these in her box, I pulled them along on a string to teach her that food doesn’t stay still and she would have to work for it if she was going to survive in the wild. I was careful to be as hands-off as possible, but sometimes when I heard her squeak for attention I couldn’t help but go and see what she wanted. She would greet me with an excited chitter.

It was always going to be difficult to persuade Twiz to separate from me. She had been so young when I took her in and I worried she was not independent enough. I began by building her an outdoor enclosure alongside another where I was about to release two more rescued weasels. Wire netting separated the enclosures and I installed cameras to watch how the animals responded to each other.

After a few days I was confident enough to put all the kits into the same enclosure. By now I had been completely hands off for 10 days but Twiz was still displaying worrying signs of attachment.

It is difficult to decide when animals are ready to release. Weasels are so tiny that there is a long list of animals that will hunt them down, including kestrels, owls, foxes, stoats (their closest relatives) and even cats. And of course if they have been hand reared, they don’t have the natural wariness that keeps their wild counterparts alive.

I decided it was now or never and so I opened the door to let all three weasels out. I felt very emotional as I watched all three kits rush around the garden giddily. But although they looked happy, their carefree play unnerved me. I would have been happier if they were more wary.

The next morning Twiz spotted me as soon as I stepped into the garden and rushed over, chittering. She kept darting under my feet - only just avoiding being trampled on. I crouched down and she rushed into my hands, whickering excitedly. This was not a good sign. I put her back into the enclosure.

Over the next few days Twiz continued to display an unhealthy attachment to me and so in the end I decided, reluctantly, to keep her. It would have been better to see her run free in the wild, but she lived in my outdoor enclosure until the ripe old age - for a weasel - of 13 months and during that time she was a wonderful companion - and a stunning model for my paintings of course.

The story of Twiz was told as part of BBC Natural World: Weasels: Feisty and Fearless. The documentary is available on iPlayer.