Butterflies of Hong Kong

Introduction

Composition of Hong Kong Butterflies

Key Species of Conservation Concern

Conservation Measures

Key Sites for Observing Butterflies

Tips for Observing Butterflies

Further Reading

Introduction

Lying on the southern coast of Mainland China, Hong Kong is geographically closely linked to Guangdong Province. Blessed with a mild climate and ample rainfall, Hong Kong is rich in flora and fauna. Although some 10,000 times smaller than China, Hong Kong has an impressive butterfly checklist of about 240 species (Lo & Hui, 2004), representing about 11 percent of the 2,153 species recorded throughout China (壽 等, 2006). This is a surprisingly high number as compared with 85 in Macau (Easton and Pun, 1999), or about 400 in Taiwan where it is far larger (台 灣 蝴 蝶 保 育 學 會, 2009).

Historic records show that Hong Kong has an accumulation of 276 butterfly species. Among them, 36 are considered occasional vagrant, doubtful species or having no recent records. After removing these 36 species, the current butterfly checklist in Hong Kong has 240 species. Although there are no endemic species, there is one endemic subspecies (Halpe paupera walthewi).

Besides having cultural and ornamental value, butterflies also play important and unique roles in ecology, science and the economy. The most widely known is the close correlation between butterflies and plants. At least 6 flora species in Hong Kong depend on butterflies to disperse pollen: Splash-of-white (Mussaenda pubescens), Hong Kong Pavetta (Pavetta hongkongensis), Glabrous Pittosporum (Pittosporum glabratum), Acronychia (Acronychia pedunculata), Long-flowered Ehretia (Ehretia longiflora) and Reevesia (Reevesia thyrsoidea) (Corlett, 2001). To scientists, butterflies are great study and research subjects, ones that lead to many other interesting investigations. In China, butterfly caterpillars are used in pharmaceutical applications. The caterpillar of Swallowtail (Papilio machaon), a vagrant that visited Hong Kong in 2004, is a Chinese medicine for stomach disorder. Indeed, butterflies bring great benefits to both nature and man. They are important insects of significant value.

Composition of Hong Kong Butterflies

According to the classification by Chou (1994), there are 17 butterfly families in the world and 12 of them are found in China. Hong Kong has ten butterfly families (Table 1).

C = common, UC = uncommon, R = rare (adopted and modified from Young and Yiu, 2002 and internal assessment.)

Well shaded by trees, forests are cooler and more humid. The forest ground is sparse in vegetation and covered with leaf litter. In these environments, the diversity of butterflies is usually low, and the species occurring here are plainer in colour (Lo and Hui, 2004). By contrast, sunny and open habitats besides woodlands, shrublands and agricultural fields are frequented by butterflies in significant numbers and species diversity.

Key Species of Conservation Concern

Before naming a species of conservation concern, one must identify, record and understand accurate information on its life cycle. Some of the rare butterflies feed on certain rare plants and have strikingly coloured patterns. These butterflies should be protected. The following are five such species.

Birdwings: Described as uncommon species, Common Birdwing (Troides helena) and Golden Birdwing (T. aeacus) are the largest butterflies in Hong Kong. Their wingspan can be as wide as 16 cm, and Common Birdwing (T. helena) is usually larger than Golden Birdwing (T. aeacus). Both species are listed as butterflies of local conservation concern by Fellowes et al (2002). They share similar habits and occur in areas where India Birthwort (Aristolochia tagala) grows. Adults often sip nectar from the flowers, and males display significant territorial behaviour. The Indian Birthwort is a climbing vine found in shrublands. It is the food plant of Birdwing larvae. Attracted by its special scent, female Birdwings lay eggs on its stems and leaves. When hatched, the caterpillars feed on new shoots, buds and leaves. After maturing, caterpillars usually pupate and hang their chrysalises on the stem of Indian Birthwort. In fact, Birdwings spend a good part of their life on Indian Birthwort.

Both species have been recorded in Po Lo Che, Fung Yuen Valley , Tai Po Kau, Ngong Ping, Tai Lam Wu, Tai Tam Country Park and Shing Mun Country Park. Records show that Common Birdwings are more widely distributed than Golden Birdwings. The former can also be found in Shan Liu, Ho Chung and Wong Lung Hang.

Common Birdwing, Troides helena

Golden Birdwing, Troides aeacus

Common Rose: Pachliopta aristolochiae is a Swallowtail (family Papilionidae) found mainly in well-vegetated valleys. It was common in the 1960's but it is now considered uncommon. It appears sporadically. In years of abundance, it can be found in relatively large numbers at sites with its larval food plants, but it may be completely absent in other years. Key sites include Po Lo Che, Fung Yuen Valley, Tai Po Kau, Ngong Ping, Shing Mun Country Park, Shan Liu and the Peak. The larvae feed on Indian Birthwort and Ford's Birthwort (A. fordiana).

Common Rose, Pachliopta aristolochiae

White Dragontail: Lamproptera curius is the smallest Swallowtail in Hong Kong. It is considered uncommon in Hong Kong. Its characteristic dragonfly-like flying pattern, transparent wing parts and tailed hind wings distinguish it from other butterflies. Its larval food plant Illigera (Illigera celebica) is protected under the Forestry Regulations of the Forests and Countryside Ordinance (Cap. 96). White Dragontail has been recorded in Po Lo Che, Fung Yuen Valley, Tai Po Kau, Shing Mun Country Park, Yung Shue O, Kak Hang Tun and Kap Lung.

White Dragontail, Lamproptera curius

Red Lacewing: Cethosia biblis is a locally rare species whose larvae feed on Passiflora moluccana, a vine of restricted distribution. This species used to have a wider distribution. During the 1960-70's, it was widely present in the New Territories and was recorded in Stanley on Hong Kong Island (Marsh, 1960). Recent records were made in Lung Kwu Tan, Lung Kwu Chau, Pui O and Shing Mun Country Park.

Red Lacewing, Cethosia biblis

Conservation Measures

Successful conservation begins with educating our younger generation. Only by communicating knowledge and appreciation of butterflies can we succeed with a long-term conservation programme. While actively promoting nature education, the Agriculture, Fisheries and Conservation Department (AFCD) has established a complete, systematic butterfly database from our baseline surveys. This data makes an important base for future monitoring and conservation programmes.

Individual Species Conservation and Legislative Protection

Common Birdwing is protected under the Wild Animals Protection Ordinance (Cap. 170) and all Birdwings (Troides spp.) are listed under Schedule 1 of the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) that regulates the trade and possession of these butterflies. In addition, Indian Birthwort and Illigera are protected under the Forestry Regulations of the Forests and Countryside Ordinance (Cap. 96). No person shall, without lawful excuse, sell or have in his possession of these plants.

Preserving Habitats for In-situ Conservation

About 80% of Hong Kong's territory is still natural, or semi-natural. Nearly half of this, 40% is designated as Country Parks and Special Areas, where plants and animals within are protected by law and managed by AFCD. Fellowes et al. (2002) identified 74 butterfly species of conservation concern. We assessed the effectiveness of Hong Kong 's protected area system in protecting these 74 species based on the existing butterfly distribution information. It was found that 73 of the 74 species have at least one locality inside the Hong Kong protected area system.

Only one species, which accounts for less than one percent of the total of butterfly species recorded in Hong Kong, is not represented in our protected areas (Table 2). This clearly demonstrates the importance of protected areas for in-situ conservation of butterflies in Hong Kong. In late 2004, in collaboration with conservation organizations such as Hong Kong Lepidopterists' Society, WWF HK, Kadoorie Farm & Botanic Garden and Green Power, AFCD selected various sites in Hong Kong as key conservation sites for butterflies, and thus assisted in mapping out our future butterfly conservation work.

* Level of concern as indicated by Fellowes et al. (2002)

Key Sites for Observing Butterflies

Wu Kau Tang and Lai Chi Wo: Partly within the Plover Cove Country Park, these two sites and the areas between them cover a variety of different habitats including woodlands, scrublands, abandoned agricultural fields and coastal areas. Some uncommon Lycaenidae and Hesperiidae, such as Club Silverline (Spindasis syama), Common Awl (Hasora badra) and Great Swift (Pelopidas assamensis), can often be seen. In addition, Yellow Coster (Acraea issoria), which is new to Hong Kong, was recently sighted in an abandoned agricultural field here. During the 2002-2009 survey, AFCD recorded nearly half of all local butterfly species in this area.

Tai Po Kau Nature Reserve: During the 2002-2009 survey, AFCD recorded 111 species in the reserve. Some uncommon butterflies, like White Commodore (Parasarpa dudu), Constable (Dichorragia nesimachus), Painted Jezebel (Delias hyparete) and Orange Oakleaf (Kallima inachus) can be found here. Chocolate Mime (Chilasa agestor), another new species recorded in Hong Kong in 2002, was discovered at this site. In Butterflies of Tai Po Kau Nature Reserve, Young and Lee (2001) listed more than half of all butterflies occurring in Hong Kong.

Pak Tam Chung: Within the Sai Kung East Country Park, Pak Tam Chung is a well-vegetated area with high butterfly diversity. During the 2002-2009 survey, AFCD recorded 105 species in this site. These included White-banded Flat (Gerosis phisara), Tailed Sulphur (Dercas verhuelli), Gaudy Baron (Euthalia lubentina) and Muirhead's Labyrinth (Neope muirheadii).

Fung Yuen Valley: Designated as a Site of Special Scientific Interest (SSSI) in 1980, Fung Yuen Valley is a forested ravine behind the village of Fung Yuen. This SSSI is recognized as an important breeding site for some butterflies of conservation concern, such as Common Birdwing and White Dragontail. Despite being located at the urban fringe, remarkably more than half of all local butterfly species have been recorded here (Young & Yiu, 2002).

Lung Kwu Tan: The fung shui wood and adjoining scrubland on the hillside in the vicinity of the Lung Kwu Tan Village are renowned for its diverse butterfly assemblages. The site is also recognised as an important breeding site of the locally rare Red Lacewing. Other uncommon butterflies found here include Striped Blue Crow (Euploea mulciber), Danaid Egg-fly (Hypolimnas misippus), and Plain-banded Awl (Hasora vitta). During the 2002-2009 survey, AFCD recorded 107 species here.

The Peak: The Peak is one of the last green havens on the heavily built-up Hong Kong Island, with relatively well preserved vegetation. In the area between Lugard Road and Harlech Road, butterflies are common. During the 2002-2009 survey, AFCD recorded 62 species in the Peak area, including the rare Red Lacewing (Cethosia biblis), Dark Edged Snow Flat (Tagiades menaka) and Chinese Windmill (Byasa alcinous).

Siu Lang Shui: Siu Lang Shui is a closed landfill where public access is restricted. Although the site has been planted almost entirely with exotic trees species, such as Eucalyptus spp. and Acacia confusa, it is an important overwintering site for Crows and Tigers (family Danaidae), mainly Common Indian Crow (Euploea core) and Blue-spotted Crow (E. midamus), and a small number of the uncommon Striped Blue Crow (Euploea mulciber) and Dark Blue Tiger (Tirumala septentrionis). Scientific research carried out by AFCD indicates approximately 32,000 - 45,000 individuals spent the 2002 - 2003 winter in Siu Lang Shui.

Crows aggregating at Siu Lang Shui

Tips for Observing Butterflies

There are 10 families of butterflies in Hong Kong, each different in shape, colour, flight pattern and other characteristics. Beginners can identify individual species by noting these features. Illustrated butterfly guides and reference information are helpful tools for learning special features and ecological characteristics. To accurately identify smaller species, such as Hesperiidae and Lycaenidae, or to distinguish similar species, you need field observation experience. The more you watch butterflies in the wild, the better you will get.

Season

Butterflies become inactive when the temperature drops below 22°C. With an average temperature of 22.8°C, Hong Kong has butterflies occurring all year round. Abundance and diversity are most marked in spring and summer between April and June, and in autumn between October and November. On particularly cold or hot days, butterfly numbers decrease drastically. Species that go through one generation of life cycle a year occur only in certain months. If you miss them, you would have to wait till next year.

Weather

Butterflies are cold-blooded animals. You often see them sun bathing themselves where there is ample sunlight. This is a good time to observe them closely, as they remain relatively still. On cloudy days their numbers drop and on days of heavy rain you would not find any butterflies at all. When the sun comes out after rain, it is one of the best times to watch them in motion.

Time

On warm days in spring and summer, the best hours to watch butterflies are 9:00-11:00 am and 2:00-4:00 pm. In autumn and winter, the best hours are 10:00-11:00 am and 2:00-3:00 pm. Although most butterflies are active during the day, some Hesperiidae and Satyridae are most active at dusk.

Place

Diverse habitats and flora provide butterflies with diverse roosting, feeding and mating environments. Common species like to visit flowering plants in the open countryside. Abandoned agricultural fields, fruit orchards, fung shui woods and most Country Parks are all ideal butterfly watching spots. In the uplands, you can find uncommon and rare species congregating at summits where they mate. Remote islands are also good places to watch rare butterflies They usually avoid windy and permanently shaded areas.

Things you need

Illustrated butterfly guide, notebook, pen, camera and binoculars.

Respect life. Do not capture any butterflies in the wild.

Further Reading

Butterfly Working Group, 2003. Migration and overwintering aggregation of Danaid butterflies in Hong Kong. Hong Kong Biodiversity, Agriculture, Fisheries and Conservation Department 6: 1-7.

Chou, I., 1994. Monographia Rhopalocerorum Sinensium. Henan Science and Technology Press, Henan.

Corlette R.T. 2001. Pollination in a degraded tropical landscape: a Hong Kong case study. Journal of Tropical Ecology 17: 155-161

Easton, E.R., Pun, W.W., 1999. Butterflies in Macau. University of Macau, Publications Center, Macau.

Hong Kong Lepidopterists' Society, 2002. Index to Butterfly Families recorded from Hong Kong. http://hkls.org/butterflies.html

Lee, Z.Y., Wang, X.Z, 2002. Butterflies in Taiwan. Owl Publishing House, Taibei. ( In Chinese: 李俊延及王效嶽，2002. 臺灣蝴蝶圖鑑 貓頭鷹出版社, 臺北.)

Lau, P., 1997. Butterflies of Hong Kong. Paul Lau Photography, Hong Kong .

Lo, Y.F., Hui,W.L., 2004. Hong Kong Butterflies. Agriculture, Fisheries and Conservation Department.

Marsh, J.C.S., 1960. Hong Kong Butterflies. The Shell Company of Hong Kong Ltd, Hong Kong.

Young, J.J., 2001. Record Euploeas hibernating at Siu Ling Shui, Tuen Mun. http://hkls.org/news/roosting/roosting.htm

Young, Y.S., Li P.C., 2001. Butterflies of Tai Po Kau Nature Reserve. Government of the Hong Kong Special Administrative Region, Agriculture, Fisheries and Conservation Department.

Young, J.J., Yiu, Y., 2002. Butterflies Watching in Hong Kong. Wan Li Book Co. Ltd., Hong Kong.

壽 建 新、周 堯 及 李 宇 飛，2006。 《 世 界 蝴 蝶 分 類 名 錄 》。陝 西 科 學 技 術 出 版 社 出 版。

台 灣 蝴 蝶 保 育 學 會，2009。 《  親 親 自 然 賞 蝶 趣 -- 台 北 賞 蝶 小 手 冊 》。台 灣 蝴 蝶 保 育 學 會 出 版。

Related Websites

Hong Kong Lepidopterists' Society

Shell Nature Watch- Butterfly Explorer