Environmental group Green Power has announced the latest results of its Butterfly Survey, which documented a total of 186 butterfly species across six butterfly hotspots. This accounts for nearly 70% of all butterfly species in Hong Kong, with 59 "Rare" and "Very Rare" species among them. The top three locations with the highest number of recorded butterfly species are Luk Keng, North District, Lung Kwu Tan, Tuen Mun, and San Tau, Tung Chung, with 149, 147, and 141 species recorded, respectively. The number of butterfly species recorded at Lung Kwu Tan and San Tau locations hit new highs, representing an increase of 11% and 21%, respectively, from the previous survey.
Environmental Affairs Manager of Green Power, Lo Wing Fung stated that the Butterfly Survey has been ongoing since 2008, with new butterfly hotspots gradually added over the years. San Tau has been a survey site since the survey's inception, while Lung Kwu Tan became one in 2018. In this latest survey, both locations had new records in species numbers. According to Lo, San Tau's environment has remained relatively unchanged over the years, and the number of butterfly species recorded has shown an increasing trend, making the new record unsurprising.
In contrast, the natural environment at Lung Kwu Tan has been steadily deteriorating over the past six years. Its natural habitats, such as shrubs, orchards, farmlands, and abandoned wetlands, have gradually been converted into parking spaces, warehouses, workshops, and other such brownfield facilities. Large areas of wetlands have also been filled in, which should lead to a decline in butterfly species, yet the latest survey recorded a new high in butterfly species numbers. Lo speculated that the reduction in natural habitats in the surrounding areas has caused butterflies to become more concentrated in their distribution, making it easier for surveyors to find them. Nevertheless, he pointed out that the reduction in habitats would inevitably create a negative impact on butterfly diversity in the long term.
New Survey Sites in Northern Lantau Island
For the first time, Sham Wat, Sha Lo Wan, and San Shek Wan on Lantau Island were included in the Butterfly Survey, where a total of 138 butterfly species were recorded. Among these, there were 31 "Rare" and "Very Rare" species, including the Orange Awlet (Bibasis oedipodae), Colon Swift (Caltoris bromus), and Bi-spot Royal (Ancema ctesia), etc. Lo mentioned that the survey results were a reflection of the rich butterfly resources in the area. He noted that due to the relatively inaccessible transportation in the surrounding areas, there has been no large-scale development or brownfield facilities, so the habitats have remained well-preserved. However, with the upcoming development of northern Lantau Island and the increase in both resident and transient populations, there will undoubtedly be growing development pressure on rural areas. He hopes that while the authorities focus on the development of northern Lantau Island, they will also strike a balance with their response to ecological needs.
About Green Power's Butterfly Survey
The Butterfly Survey, launched in 2008, adjusts its survey sites each year depending on their conditions. The survey is conducted by "Butterfly Surveyors", who are citizens that have been trained and certified. It typically starts in June or July each year and continues until the following May or June, which allows for ongoing comparison of butterfly resources and environmental changes at different survey sites. The latest Butterfly Survey (2023 – 2024) was conducted by 235 butterfly surveyors across six sites.