As we approach the end of our most intense period of filming, there is a bit of a competition going on in the Life team as to who has filmed the most bizarre story of the series.

Since the last report the claims have been coming thick and fast, but if pressed I would say the current leader is Adam Chapman and his Hawaiian waterfall-climbing fish! The star of this story is a colourful goby that spends the earliest part of its life in the shallow coastal waters off Hawaii, as any normal goby would. But then, when it is time to breed, it heads for fresh water – and this is where it gets bizarre, because the freshwater pools it needs are at the top of a waterfall over 20 metres high!

With extraordinary pluck, braving a deluge of water, the little fish clamps itself onto the vertical rock face (using its ventral fins that are modified into a sucker), and in what is the equivalent of you or me climbing the Empire State Building in a power shower, proceeds to loop its way up to the top. It’s two steps forward, one step back as he gets knocked back again and again by the massive force of water… when you see him finally make it you can’t help cheering!

As well as being great entertainment this story perfectly encapsulates the aims of Life: extreme behaviour revealing an almost unbelievable solution to some extraordinary challenge thrown at an animal by mother nature, and a beautiful example of ‘evolution in action’.

In our three-year quest for the best stories there have been many other contenders of course, as the Life team have been to the four corners of the planet and continued to push the use of revelatory filming technology; dung-collecting owls, cart-wheeling toads, flies growing their eyes on the end of giant stalks (which are the same length as their bodies) and hippos having their teeth cleaned by shoals of fish have amazed us back at base.

As well as the strange, we have also been on the trail of the spectacular and dramatic. We’ve been tracking with vast elephant herds, using our new ‘yogi-cam’ to rub shoulders with the matriarch as she leads them across the Amboseli plains. We’ve been joining enormous flocks of knot as they make their critical refuelling stop on their 1000-mile plus migration; watching the perilous fledging of baby snow geese as they leap from their clifftop nests into thin air (before they can fly); and spying beneath the waves on huge spider crabs as they come together in their thousands to moult.

Staying underwater we’ve been back to our very own shipwreck (which we sank at the beginning of shooting to show how a coral reef evolves). It’s progressing well. The corals are beginning to colonise the decking, an octopus has taken up residence in the funnel and the hull is coated with all sorts of marine creatures. There’s even a shark which likes to pay regular visits.

The series has tried not only to deliver beautiful, enthralling images but new scientific revelation, and one of the signatures of Life has been the use of ultra-high-speed cameras to show previously unseen action. In Belize, Madagascar, Peru and here in England images taken at up to 8000 frames a second have shown how a Jesus Christ lizard really runs on water; what it’s like to be on the receiving end of a chameleon’s tongue; the mating dance of the spatule tailed humming bird; and the way plants turn their seeds into ballistic missiles.

We still have many miles to go in the last few months of filming. In South America we’re looking forward to mass hunting by dolphins and the parental care of poison arrow frogs. In the Falklands we will be returning to film more of an amazing orca hunting behaviour. And, at last, I am going on location – heading to McMurdo base in Antarctica to film the strange creatures that live on the sea bed beneath the ice!

We are also off to West Papua to film two extraordinary birds, the Volgelkopf bowerbird and the king bird of paradise. This is an extremely tough assignment for cameraman Barrie Britton and director Stephen Lyle; it’s a very remote location and these amazing birds are very secretive. Their displays to attract a mate are almost beyond belief, including building a huge tent out of hundreds of orchid stems, each carefully collected from the surrounding forest, and, in the case of the king bird of paradise, doing a dance that resembles a scene from Monty Python’s ‘dead parrot’ sketch. Which I suppose neatly brings me back to the weird side of nature.

Maybe one of these birds will knock the waterfall fish off the top slot for the most bizarre story of Life!