Green Power announced a survey today about newly discovered butterflies and their relationship to rising temperatures.

Five new species were discovered in Hong Kong for the first time, including the white royal, the painted lady, the dark palm dart, the common line blue and the lime butterfly.

Matthew Sin Kar-wah, senior environmental affairs manager, said they discovered 67 common archdukes and 33 tailless line blue, which were first recorded back in 2018 and 2019.

Sin suggested how hotter areas attract butterflies to migrate as well. In 2019 and 2020, the hottest and the second hottest year in Hong Kong, the survey recorded the highest and second highest numbers and species of butterflies respectively. “It indicates that there will be more butterflies as the temperature goes up,” he noted.

“It is possible that butterflies from other tropical and subtropical areas migrate to Hong Kong because of its rising temperature in recent years,” Sin said.

For example, common archduke and tailless line blue that are recorded within this decade, are usually found in Thailand and Malaysia, according to Sin.

“These species might have been to Hong Kong before,” Sin added, “by the import of various plants or by typhoons and monsoons.”

Yet the environment might not be fit for their reproduction, explaining why their growth can only be seen recently.

However, the numbers dropped for the blue admiral and the Chinese peacock, which are commonly seen in Hong Kong. Their overall numbers decreased by 63 and 73 percent respectively, compared to that between 2005 and 2009.

Still, the overall numbers and species of butterflies increased after including the decrease of local common butterflies. The survey recorded 125 species and over 6,600 butterflies in total, marking two second highest data in 16 years.

“As the overall climate of Hong Kong becomes more heated, a ‘new normal’ for the structure of local butterflies flocks is expected,” Sin said.