Tropical insects on Mount Kinabalu, Malaysia’s highest mountain, in Borneo, have moved uphill to cope with changes in climate, a recent survey by British researchers found.

The study, carried out by the University of York researchers, found that the insects have moved up in search of cooler places by about 220 feet or 67 metres between the first survey carried out in 1965 and the recent one in 2007.

mount-kinabalu

University of York said in a press release that its PhD student, I-Ching Chen — the first author of the study — said the findings demonstrate that climate change is affecting the distributions of tropical insects.

Potentially bad for biodiversity

“Tropical insects form the most diverse group of animals on earth but to-date we have not known whether they were responding to climate change,” he said. The new study confirmed that they had been affected by the change in the climate and this, he said, “is potentially bad for biodiversity.”

Professor Chris Thomas, who led the study, said, “Large numbers of species are completely confined to tropical mountains, such as Mount Kinabalu: many of the species found by the expeditions have never been found anywhere else on earth.”

Smaller space uphill, some species likely to die out

He added that “as these species get pushed uphill towards cooler conditions, the amount of land that is available to them gets smaller and smaller. And because most of the top of the mountain is bare rock, they may not be able to find suitable habitats, even if the temperature is right.”

Some of the species are likely to die out, he said.

The New Expedition in 2007 was joined by Henry Barlow, one of the members of the original survey, whose life-long enthusiasm for moths helped I-Ching Chen, who is from Taiwan, to come to terms with the sheer diversity of moths she had to identify.

Jeremy Holloway, a Research Associate at the Natural History Museum in London, and another member of the 1965 expedition, devoted his career to the identification (taxonomy) of moths from South East Asia, enabling the research team to identify the new samples. Armed with the data from 1965, moth-trapping equipment, tents, sleeping bags and rations, I-Ching and colleagues set out to repeat the original survey.

“Photographs from the 1965 expedition led us back to exactly the same sites sampled 42 years ago,” said Dr Suzan Benedick, expedition member, and Universiti Malaysia Sabah entomologist.

The new survey involved climbing the mountain and catching moths up to an elevation of 3,675 metres above sea level. Once all of the specimens had been caught and identified, then the team compared the heights at which each species had been found in 1965 and again in 2007.

The results revealed a highly statistically significant shift, indicating that the moths are now found higher on the mountain than previously.

Some positive news

There is a more positive note, however. As the highest and coolest location between the Himalaya and New Guinea, Mount Kinabalu represents an extremely important “climate change refuge.”

Species that begin to find conditions too hot (or dry) in the surrounding lowlands may be able to find suitable conditions by moving upwards on the slopes of this mountain, the report suggests.

“The critical thing is to protect the forests surrounding the mountain, so that the lowland species are able to reach the cooler conditions that they may need,” said Dr Jane Hill, expedition member, and one of I-Ching Chen’s advisors.

Extract

Below is the extract of the study, titled Elevation increases in moth assemblages over 42 years on a tropical mountain, which appears in the Proceedings of the National Academy of Sciences.

“Physiological research suggests that tropical insects are particularly sensitive to temperature, but information on their responses to climate change has been lacking—even though the majority of all terrestrial species are insects and their diversity is concentrated in the tropics.

Here, we provide evidence that tropical insect species have already undertaken altitude increases, confirming the global reach of climate change impacts on biodiversity.

In 2007, we repeated a historical altitudinal transect, originally carried out in 1965 on Mount Kinabalu in Borneo, sampling 6 moth assemblages between 1,885 and 3,675 m elevation. We estimate that the average altitudes of individuals of 102 montane moth species, in the family Geometridae, increased by a mean of 67m over the 42 years.

Our findings indicate that tropical species are likely to be as sensitive as temperate species to climate warming, and we urge ecologists to seek other historic tropical samples to carry out similar repeat surveys.
These observed changes, in combination with the high diversity and thermal sensitivity of insects, suggest that large numbers of tropical insect species could be affected by climate warming.

As the highest mountain in one of the most biodiverse regions of the world, Mount Kinabalu is a globally important refuge for terrestrial species that become restricted to high altitudes by climate warming.

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