Climate change pushes moths up mountain

29 January 2009

Populations of moths living on a mountain in Borneo have moved uphill by more than 60m over the last 40 years, new research shows today.

This is the first demonstration that climate change is affecting the distribution of tropical insects, the most numerous group of animals on Earth.

The new research, led by the University of York, repeated a survey that was originally carried out in 1965 by a three-student team from Cambridge. Their expedition took them 3,675m above sea level up Mount Kinabalu in the Malaysian State of Sabah, where they trapped and identified moths.

Different environmental change theories

Jeremy Holloway, moth expert and a scientific associate at the Natural History Museum, was part of the original team and explains the different theories about environmental change at the time.

‘When I visited the mountain in 1965, climate scientists were talking more about the planet entering another Little Ice Age rather than being worried about human activities causing global warming.’

Moving up the mountain

The 2007 study showed that as the climate has changed over the years, the moths had to move further up the mountain to find the cooler environment they preferred. On average the populations of moths occurred 67m higher than they had 42 years earlier.

More vulnerable

As they retreat from the surrounding lowlands to the mountain summit, the area of suitable habitat gets smaller and smaller, making them more vulnerable. 

This horse-shoe shaped summit is bare granite, with stunted vegetation only where there are cracks and crevices, and so it is surprising any creature would survive here at all. 

However, 4 species of moth were found living there (they are endemic and live no where else), including the Hypocometa titanis species shown in the image at the top of the page.

Climate refuges

The team says that these areas could become climate refuges for species living at lower levels – they would be able to move upwards as the climate changes the mountain environment in the future.

Fortunately the mountain is conserved as a Sabah State Park, however the team highlights the importance of conserving the forested areas surrounding the mountains too.

Identifying moths

Holloway helped identify more than 150 species of moths collected from the two expeditions. With such a huge task, he used the Natural History Museum’s collection of 9 million moth and butterfly specimens to help him.

The process of describing, naming and sorting organisms is known as taxonomy and is a crucial first step in any study of the natural world. Understanding current levels of biodiversity is important before you try and protect it.

Specimens from the expedition in the 1960s are looked after at the Museum and, combined with newer material and historic material collected over the last 200 years, they form an important resource that will help with future conservation.

Naming over 4000 moths

‘After 25 years, I have been able to produce 18 monographs (short books) on the larger moths of Borneo,’ says Holloway. 

'They cover about 4500 different species and about a quarter of them are new to science.’

Holloway concludes, ‘This work is providing, both in hard copy and online, a sound taxonomic foundation for future environmental surveys of moths in Southeast Asia.’

This study is published in the latest edition of Proceedings of the National Academy of Sciences (PNAS).