Environmental group Green Power has published the results of its latest butterfly survey, recording a total of 189 butterfly species in seven butterfly hotspots. This accounts for over 70% of all butterfly species in Hong Kong, including 60 rare butterfly types (“Rare” and “Very Rare” species). The top three locations with the highest number of recorded butterfly species are Wu Kau Tang in Tai Po, Lung Kwu Tan in Tuen Mun, and Luk Keng in the North District, with 140, 132, and 130 species recorded, respectively. Among them, Wu Kau Tang and Lung Kwu Tan recorded the highest number of butterfly species since the 2008 Survey, showing a 77% and 22% increase, respectively, compared to the previous survey. Additionally, for the first time in Luk Keng, the “Very Rare” Chinese Windmill (Byasa alcinous) was sighted, and three butterfly species only recently discovered in Hong Kong, namely the Fluffy Tit (Zeltus amasa), Silver Royal (Ancema blanka), and Lesser Gull (Cepora nadina), were recorded in multiple locations, indicating that these three species, originally native to tropical regions, have taken root in the local habitat.
Ms Helen Yau, Assistant Senior Education & Project Manager, pointed out that the survey indicates an upward trend in the number of butterfly species in Hong Kong in recent years, which reflects the increasing maturity and stability of natural habitats in the local countryside. Many areas surrounding the countryside have evolved into complex ecosystems such as freshwater wetlands and secondary forests due to minimal human interference, providing ideal habitats for various wildlife, including butterflies.
Chinese Windmill Sighted for the First Time in Luk Keng, Tropical Butterflies Multiplying in Hong Kong
For the first time in the survey, the “Very Rare” Chinese Windmill was recorded in Luk Keng. Ms Helen Yau noted that consistent sightings of this butterfly were restricted to the high mountains of Hong Kong. Its presence in the northern region is unusual, and it is speculated that the Chinese Windmill recorded this time may have crossed the borders into Hong Kong from the mainland, as Luk Keng is located near the borders and adjacent to the Wutong Mountain National Park. She pointed out that the northern border region serves as an ecological corridor between Mainland China and Hong Kong, and urged authorities to carefully assess the impact of development in the northern area on the ecological environment.
As for the Fluffy Tit, Silver Royal, and Lesser Gull recorded in this survey, they are new butterfly species discovered for the first time in Hong Kong in 2021. All three have remained “unclassified” since. Ms Helen Yau said that the fact that the survey recorded these three butterfly species in multiple locations, with the Fluffy Tit documented in as many as five surveys, indicated that these new butterfly species have adapted to the environment of Hong Kong, and she expected their populations to continue to expand and grow. However, as these three butterfly species used to thrive in tropical regions, Ms Helen Yau acknowledged that their successful settling in Hong Kong has been evidently linked to the steadily increasing hot days in Hong Kong. She expressed concerns that intensifying climate change would gradually eliminate native temperate butterfly species and urged the government to commit to promoting carbon neutrality in Hong Kong to mitigate the impact of climate change on the natural ecosystem.
Effective Conservation of Butterfly Resources in the “Regulated Area” of South Lantau
This survey also covered two locations in South Lantau, namely Mui Wo, and Shui Hau and Tong Fuk. The former recorded 113 species, while the latter recorded 102 butterfly species, a relative abundance of butterfly resources. Regarding the recent decision by the Development Bureau to designate an ecologically valuable area of over 620 hectares within the “South Lantau Coast Outline Zoning Plan” as a “Regulated Area”, Ms Helen Yau said that this measure has enabled authorities to enforce the law against land-use violations more effectively. She believes that this would serve as a deterrent against environmentally destructive activities in the countryside, such as illegal construction waste dumping, riverbed filling, and large-scale deforestation, and would be expected to reduce instances of “destroy first, develop later”. She hopes that in the future, the authorities will enforce regulations more decisively, and thoroughly implement the conservation policies formulated for South Lantau.
Remarks: Launched in 2008by Green Power, the Butterfly Surveyor scheme trains members of the public tobecome qualified Butterfly Surveyors. The surveys begin in June/July each yearand end in May/June the following year. Butterfly species number andenvironmental changes of various butterfly hotspots were monitored over theyears. In 2022-2023, we had 171 surveyors monitoring seven butterfly hotspots.