Lamma Island Biodiversity

WWF HK
WWF HK
May 31, 2019 · 6 min read

by Thomas Gomersall

Amid Hong Kong’s rapid urban expansion, it’s hard to imagine a more slow-paced environment in the city that allows for greater expanses of green spaces. But you can find it just a 30-minute ferry ride away from Central, on Lamma Island.

The two places could hardly be more different. Whereas Central features tightly packed high-rises, Lamma has only two small urban hubs (Sok Kwu Wan and Yung Shue Wan) with the rest of the island being natural forest or low-density village housing. Whereas Central has a crisscrossing network of MTR, highways and overpasses, Lamma has only walking trails and cycle paths. And while Central seems largely devoid of wildlife, butterflies flitting through trees are a common sight even in the most urbanised parts of Lamma.

With so much green space, it is hardly surprising that the island is home to a rich array of Hong Kong wildlife. A walk along its beaches and through its forest is bound to turn up at least some of the species listed below, especially at night.

Photo credit: Thomas Gomersall

Green Turtle (Chelonia mydas): Designated as a Site of Special Scientific Interest (SSSI) since 1999, Sham Wan beach in the south of Lamma is the only regular green turtle nesting beach in Hong Kong. Every year from June to October, unauthorised entry to the beach is prohibited (offenders are liable to a HK$50,000 fine) and a speed limit on boats is implemented to prevent collisions with turtles. Prior to this period, any garbage or plants that might limit movement of turtles are removed (Agriculture, Fisheries and Conservation Department, 2018). Still, there have been few recorded nestings over the past several years, with the last one occurring in 2012. Male turtles that greet and mate with the females in shallow waters before nesting are likely to be disturbed by beach-goers and jet skiers that continue to visit during the closed season (Lau, 2014). Yet as of 2018, nobody has been charged for it (Knott, 2018). Any turtles that may hatch there in the future face the additional threat of climate change as warmer sand will lead to a heavily female biased population (turtle genders are determined by the temperature their eggs are incubated at), threatening its long-term survival. If Hong Kong wants to preserve its turtles, better law communication and enforcement and immediate, long-term action to address the impacts of climate change on them are urgently needed.

Last year, a study from the Caribbean identified two simple, cost-effective ways of dealing with the latter problem: shading nests with palm leaves and relocating them to cooler beaches (e.g. ones more exposed to wind). A combination of these was found to significantly lower nest temperatures and was projected to reduce sex ratios to 97-100 per cent female to 60-90 per cent (Esteban et al, 2018).

Photo credit: Billy Hau

Spotted Black Cicada (Gaeana maculata): Lamma is a paradise for insects in Hong Kong, with a casual stroll along its forested walking trails likely to turn up a wide variety of species, from butterflies to stinkbugs. But in March and April, they are joined by the loud, electric whirring of large numbers of spotted black cicadas (Hong Jian, 2006, p. 31). During the mating season, adults will emerge en masse from underground and the males will clamber up trees and other plants, where they will display to the females with deafening songs of up to 120 decibels (louder than a rock concert). To produce this sound, the males have two corrugated exoskeleton membranes at their rear end called tymbals that click as they contract and relax their internal muscles. The click is in turn amplified by the cicada’s hollow abdomen, which it will move towards or away from what it is resting on in order to modify its song (Ferguson, 2018). After mating, the adults all die and their young will eventually burrow into the soil where they will begin their development into adult cicadas and restart the cycle (Ferguson, 2018; Hong Jian, 2006, p. 31).

Photo credit: Timothy Bonebrake

Large Woodland Spider (Nephiles pilipes): With so many flying insects around, it’s little wonder that Lamma is also a good place to find one of Hong Kong’s most iconic spiders, whose webs dot the sides of the jungle walking paths here. The yellow patterning on its body is used to lure nocturnal flying insects to its web. On the urban fringe, however, it faces a challenge as artificial light makes it easier for prey to spot their webs in the dark, lowering the rates of prey capture (Yuen & Bonebrake, 2017).

Photo credit: Timothy Bonebrake

Asiatic Painted Frog (Kaloula pulchra): Another animal that benefits from Lamma’s abundance of insect life is one of Hong Kong’s most colourful frogs. Despite being largely nocturnal, spending the day hiding buried beneath damp soil or underneath other objects, the Asiatic painted frog is not that hard to find, being fairly easy to spot in the open at night. Its presence can also be verified by its very loud call, which has been compared to that of a cow. When threatened it will inflate its body and secrete a sticky mucus from its skin that deters many predators, with the exception of the Chinese cobra. Although forests are its natural habitat, it has also been recorded in drainage holes and even dry areas far from water (Karsen et al, 1998).

Photo credit: John and Jemi Holmes

Pacific Reef Heron (Egretta sacra): Instantly recognisable thanks to its ashy grey plumage, the Pacific reef heron is a widely distributed but uncommon bird in Hong Kong. As its name suggests, it is a specialist of coastal ecosystems and will rarely venture into fresh or brackish water, unlike the more common great and little egret. Also unlike the other egret species, it is largely solitary. While sightings are unpredictable, they are usually found on rocky shorelines, with the best time for viewing at low tide, when they will venture out into the shallows to spear fish. When nesting, it will build a stick nest amongst the rocks near the high tide mark (Tipper, 2016, p. 30; Viney et al, 2005, p. 44). On Lamma Island, it can sometimes be seen resting on the boats off Yung Shue Wan ferry pier.

References

· Agriculture, Fisheries and Conservation Department, Conservation of sea turtles in Hong Kong: The Sham Wan Restricted Area, [website], 2018, https://www.afcd.gov.hk/english/conservation/con_fau/con_fau_sea/con_fau_sea_con/con_fau_sea_con_the.html , (Accessed: 29 May 2019).

· Esteban, N., Laloe, J.O., Kiggen, F.S.P.L., Ubels, S.M., Becking, L.E., Meesters, E.H., Berkel, J., Hays, G.C., M.J.A. Christianen. 2018. ‘Optimism for mitigation of climate warming impacts for sea turtles through nest shading and relocation.’ Scientific Reports, 8, 17625.

· Ferguson, R., ‘The loudest insect known to man? Have you heard them yet?’, Wild Creatures Hong Kong [web blog], 2 May 2018, https://www.wildcreatureshongkong.org/single-post/2018/05/02/The-loudest-insect-known-to-man-Have-you-heard-them-yet, (Accessed: 11 April 2019)

· Hong Jian, F. 2006. Photographic Guide Series of Hong Kong Nature (8): Amazing Insect World, Jan KC Chan, HK Discovery Limited, Hong Kong. 31pp.

· Karsen, S.J.,Lau, M. and A. Bogadek. 1998. Hong Kong Amphibians and Reptiles: Second Edition. Provisional Urban Council, Hong Kong. 68pp.

· Knott, K., ‘Actors and activists fight for endangered green turtles’ nesting site in Hong Kong’. South China Morning Post, 26 June 2018, https://www.scmp.com/lifestyle/article/2152477/actors-and-activists-fight-endangered-green-sea-turtles-nesting-site-hong (Accessed: 20 May 2019).

· Lau, M., ‘Give Hong Kong’s green turtles a fighting chance to survive’. South China Morning Post, 6 June 2014, https://www.scmp.com/comment/article/1526646/give-hong-kongs-green-turtles-fighting-chance-survive (Accessed: 30 May 2019).

· Tipper, R. 2016. A Naturalist’s Guide to the Birds of Hong Kong, John Beaufoy Publishing, United Kingdom. 30pp.

· Viney, C., Phillipps, K. and C.Y. Lam. 2005. The Birds of Hong Kong and South China. Information Services Department, Hong Kong SAR Government, Hong Kong. 44pp.

· Yuen, S.W. and Bonebrake, T.C. 2017. ‘Artificial night light alters nocturnal prey interception outcomes for morphologically variable spiders’. Peer J, 5 e4070.

Panda blog @WWF-Hong Kong

WWF HK

Written by

WWF HK

WWF contributors share regular insights on Hong Kong biodiversity and conservation issues

Panda blog @WWF-Hong Kong

WWF contributors share daily insights on Hong Kong biodiversity and WWF-Hong Kong projects

WWF HK

Written by

WWF HK

WWF contributors share regular insights on Hong Kong biodiversity and conservation issues

Panda blog @WWF-Hong Kong

WWF contributors share daily insights on Hong Kong biodiversity and WWF-Hong Kong projects

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