Explosion in Hong Kong butterfly population linked to hottest year ever
- Environmental group recorded 127 species of butterfly in 2019, up on 113 a year earlier
- Four rare species spotted for the first time in the city since surveys began in 2005
Environmental group Green Power recorded 127 species of butterfly and more than 7,800 individuals across Shing Mun Country Park and Tai Po Kau Nature Reserve, both areas under environmental protection. The locations were selected to allow the survey to focus on the effect of climate on butterfly populations and minimise other factors from human activity.
“Our 2019 survey showed climate change had induced a sharp increase in the butterfly population. In the long term, this may not be a good thing,” said Matthew Sin Kar-wah, senior environment affairs manager at Green Power, which has been surveying butterfly numbers annually since 2005, and has never counted a bigger population than last year’s.
Green Power found 113 species in 2018, and last year’s numbers were 50 per cent higher than the average population from 2005 to 2018.
Butterflies act as pollinators for plants to help them reproduce, and as food for birds and other animals. Any significant changes in their populations could in turn affect the local ecosystem, Sin said.
Fluctuations in temperature could change the time when caterpillars hatch, which could lead to them eating more plants or young birds having less food, if they hatch early or late.