Life amongst the volcanoes

After his trip to Guyana last year Oxford's George McGavin recently led an expedition to Papua New Guinea as part of BBC One's Lost Land of the Volcano.

The first part of the series went out on Tuesday [watch it on BBC iPlayer] but, with two more episodes still to come, I quizzed George about his latest adventure, the new species the team discovered and how they coped with humidity, leeches and lava bombs:

OxSciBlog: Why is Mount Bosavi such an interesting place to study?
George McGavin: Mount Bosavi, which rises to a height of 2,507 metres (8,225 ft) above sea level, is the collapsed cone of an extinct volcano in the Southern Highlands of Papua New Guinea that last erupted some 250,000 years ago in the Pleistocene.

What makes this area so interesting is that it is remote, relatively unexplored and the difficulty of accessing the crater means that hunting pressure on the animals inside is currently very low. Additionally, the top of Mount Bosavi, being an isolated montane habitat, will harbour species not found in the surrounding lowland forest.

OSB: What species there captured your imagination?
GMcG: The forest is filled with weird and wonderful species from pygmy parrots and giant rats to squeaking beetles and grunting fish. Halfway through the expedition I found and photographed a small group of caterpillars, which I had never seen before. They sat on a branch in a snake-like group and when threatened thrashed around violently.

The only way of finding out what they were was to rear them through to adulthood in a cage. They pupated but nothing happened until the very last morning when we were due to leave. I had transferred them into a small box in the hope that they might emerge - and they did! - I opened the box to see three large and colourful, fruit-piercing noctuid moths (Eudocima iridescens).

OSB: What were the challenges of filming in the crater?
GMcG: Filming in rain forest is tough on equipment and people. Constant high humidity does not go well with sophisticated microelectronics and all the essential camera gear was kept in custom built hotboxes over night to make sure they were dry - even if we were not.

One team filmed inside the 'white water cave' of Mageni on New Britain and had to wade, scramble and climb their way deep into the heart of a mountain. It was like travelling through the world's greatest jet-wash. The enormous quantities of water and spray gave the cameras and sound equipment a hard time but they still managed to film some extremely exciting new passages as well as the cave’s natural inhabitants, bats, leeches and cave crickets.

Another smaller team visited Tavurvur an active stratovolcano near Rabaul in East New Britain. During the time we were filming, Tavurvur became unusually and spectacularly active, throwing up huge plumes of ash and ejecting some large volcanic ‘bombs’ a kilometre into the air some of them flew over and landed near our camp site - forcing a very hasty early morning retreat.

OSB: Why is protecting the wildlife of places such as Papua New Guinea so important?
GMcG: Recent analyses of thirty years of satellite imagery for Papua New Guinea have found that 19.8 million acres of forest was lost between 1972 and 2002. At the rate forest is being cleared or degraded more than 80 percent of the country's accessible forest - and more than half of the total forested area will be gone or severely damaged by 2021.

The loss of what is the world's third-largest rain forest would see the extinction of a unique flora and fauna and have devastating and far-reaching effects on the physical environment, regional weather patterns and the lives of the people that live there.

And it’s not just the forest and its species we will lose. As the process of logging releases huge amount of carbon dioxide into the atmosphere, continuing deforestation make it virtually certain that the world as a whole will not be able to escape the worst effects of global climate change.

The next part of Lost Land of the Volcano will be broadcast on BBC One, 15 September at 9pm, with the third part airing on 22 September at 9pm.

Dr George McGavin is an Honorary Research Associate at the Oxford University Museum of Natural History.