To cope with the impact of climate change, butterflies need "cool spots"

Source: Science and Technology Daily

It is understood that in the past 30 years, climate change has made the northern part of the United Kingdom warmer and warmer, so many butterflies have expanded their range of activities to the north of the United Kingdom. But at the same time, the range of butterfly species that are more adapted to cool environments is also shrinking.

Previously, there was little research on the effects of temperature changes on butterfly populations, so researchers in the United Kingdom began to study how butterfly populations respond to the impacts of climate change. At the end of September, the results of the study were published in the journal Animal Ecology.

For the study, the researchers captured a total of 4,000 wild butterflies from nearly 29 species, using precision detectors to measure the body temperature of each one. They also measured the temperature of the surrounding air, and for butterflies that prefer to inhabit plants, they also measured the ambient temperature of their habitat. These data suggest that many butterflies are adept at finding specific environments to regulate their body temperature.

The habitat environment helps butterflies regulate their temperature

Studies have shown that all butterflies are temperate animals, and they cannot produce heat on their own. The ability of different butterfly species to maintain a suitable body temperature varies significantly, and a considerable number of butterflies need to regulate their body temperature through changes in the temperature of the external environment.

Larger, lighter-colored butterflies, including European pink butterflies and hooked butterflies, are most well adapted to fluctuations in ambient temperature. They can adjust their huge pair of wings according to the direction of the sun, reflecting sunlight at different angles, so as to achieve the purpose of dissipating heat or letting more sunlight shine on the body. The population of these butterflies is relatively stable, and some of them continue to grow.

However, smaller butterflies, such as the Pan Fei Zhen eye butterfly, have a very bad ability to regulate body temperature autonomously. Now, these butterflies are at great risk of population decline.

The study found that butterfly species that are not in their own condition to regulate body temperature can find places with specific temperatures in the natural environment, such as shade, and then control their body temperature with the help of such a "microclimate" environment.

However, the researchers found through the investigation that this ability to adjust body temperature with the help of the natural environment did not help the "thermal experts" among these butterflies to live better, for example, in the past 40 years, the population of the love gray butterfly and red gray butterfly has decreased significantly.

The study notes that two-thirds of butterfly populations in the UK have experienced a decline in numbers: habitat loss and fragmentation, and the homogenization of the natural environment have wiped out the microenvironment on which many butterflies depend. This, combined with the fact that climate change has led to more extreme weather events, triggering greater temperature fluctuations, has complicated the survival of butterflies.

The protection of the natural environment needs to be more rational and systematic

More than 85% of human food crops are known to require insects, including butterflies, to pollinate, and these insects provide vital services worth billions of pounds worldwide. At the same time, protecting species diversity will provide natural ecosystems with greater resilience: insects are an important food source for many other species, including birds, and if the number of one insect species declines, other insect species will need to fill the gap.

"Many butterflies rely on micro-habitats with the right temperature to regulate their body temperature, and for them, climate change and habitat loss are undoubtedly fatal blows." First author Dr Andrew Bretton, a postdoctoral research assistant in the Department of Zoology at the University of Cambridge, said.

He added: "To preserve the diversity of butterfly species, we need to enrich the morphology of the geographical landscape. For example, in the garden lawn, we can also make the grass grow longer and more luxuriant, providing cooler shade for butterfly species. Within nature reserves, we can set aside areas for herbivores to nibble on or cut down moderately, while the rest of the areas remain in their natural native state. In addition, it is possible to add shrub fences and dig ditches to the farm. ”

Previous studies have confirmed that geographical landscapes with highly heterogeneous natural features have a wider range of temperature variations. Because diverse ecological structures can create different microenvironments, they can help butterflies regulate body temperature.

Previously, many scholars in related fields believed that butterflies have almost harsh requirements for habitat selection, but the specific reasons have not been confirmed. Through this study, it was found that butterflies are not so much picking habitats as they are picking the temperature of the environment they can inhabit.

Ed Turner, PhD of Zoology at the University of Cambridge, who led the study, said: "When we develop conservation measures against the impacts of climate change, we not only understand the habitat requirements of different butterfly species, but also focus on their temperature requirements. ”

He added: "Based on this research, humans need to maintain the natural environment more rationally and systematically, thereby protecting the diversity of butterfly populations, which may also protect other insects." ”