Insects dine out on wild feast

Watching a dead animal rot may not sound like everyone’s idea of fun but for insect expert Sarah Beynon it can provide a feast of information.

Sarah, from Oxford University’s Department of Zoology, took part in Hippo: Nature's Wild Feast which airs tonight on Channel 4, 9pm. The programme reveals what happens to the carcass of a hippopotamus in the wild over a week, using high-tech equipment to track the vast array of predators, scavengers and insects that strip the body down to the bone.

‘The hippo is essentially a whole ecosystem to an insect,’ Sarah tells me. ‘During the decomposition process, it goes through five stages of decay; fresh, bloated, active decay, advanced decay, and remains. Each stage supports a unique suite of insects.

‘Also, the different parts of a hippo support different insects - the flesh, skin, bones and gut contents all have different species feeding on them. In fact, insects are the only creatures that will feed directly on the tough, dry skin.’

The hippo carcass studied by the team was located in Zambia's Luangwa Valley. Sarah explains that in Africa such a body may support more than 300 species of insect, with millions of individual insects calling the carcass home.

Sarah was one of the scientific team studying the carcass, her work included observing insect behaviour, collecting specimens, and then commenting on each day’s footage for the programme.

‘My personal highlights were getting up close and personal to the hippo carcass,’ she reveals. ‘I had to don a fully protective plastic boiler suit and mask to guard against potential disease, and being out in 46˚C heat (ground temperature 64˚C), it was rather warm to say the least, but well worth it to see the wealth of insect life up close and personal.

‘The metallic green hide beetles were feasting on the parched skin, whilst a host of hister beetles were preying on all other insects feeding on the carcass.’

But with such a massive meal on offer she had to be on the lookout for some of the larger diners: ‘We got stranded at night on the river bed right next to the hippo carcass surrounded by well over 200 crocodiles and 7 hyenas!

‘We got the vehicle stuck in the sand and had to dig it out in torchlight with the hyenas and crocs waiting for us to leave so they could resume their feast. Seeing so many pairs of eyes glowing in torchlight was an awe-inspiring experience.

‘In fact, every time I went filming insects, we always seemed to run into the large game at very close proximity - a herd of elephants when setting the light trap, and hyenas when searching through dung for dung beetles! Quick retreats were called for in all cases!’

Whilst the cameras recorded animals visiting the hippo day and night Sarah and the team found innovative ways to study the insects – using radio transmitters mounted on individual insects to track their movements. She believes this technology has great potential, particularly in investigating the large-scale impacts of pesticides on insect populations.

The filming may be over but Sarah is flying back with plenty of new data and specimens that could still spring some surprises: ‘All specimens taken will be identified, with the hope of finding species new to science. When I was in Zambia last year, I found a sub-species new to science, so it is very possible, as the country is so under-studied.’

Hippo: Nature's Wild Feast airs Monday 7 November 2011 on Channel 4, 9pm.