Island House Biodiversity
by Thomas Gomersall
In 1986, Island House was leased to WWF-Hong Kong as a conservation studies centre. Since then, its primary goal has been to engage and educate people about the importance of nature to our lives and the need to live sustainably through activities such as eco-visits, wildlife surveys and sustainability-themed events. It’s certainly an appropriate location for such things, with a garden brimming with birds, butterflies and bees, as well as the 140 species of flora that were planted by former Hong Kong Chief Secretary Sir David Akers-Jones and his wife when they lived here from 1985 to 1987. Not to mention the insects, crabs and other creatures scuttling along its shoreline.
This weekend (31 August-1 September), the Reconnect with Nature Festival will offer an excellent chance to experience the natural wealth of Island House in person. So here are five species you may expect to find whilst wandering its garden and shoreline.
Asian Koel (Eudynamys scolopaceus): You may not have seen this bird before, but you probably have heard it before. Its loud, whooping cry of ‘ko-el, ko-el’ is an iconic sound in Hong Kong wherever there are trees, even in urban areas (Tipper, 2016, p. 77). A member of the cuckoo family, like many of its relatives the Asian koel is a brood parasite, laying its eggs in the nests of black-collared starlings, common magpies, blue magpies and masked laughingthrushes, with the chick hatching several days before those of the host bird (Ferguson, 2019; Viney et al, 2005). Unlike other cuckoos, however, the koel chick does not kill or evict its foster siblings from the nest (Ferguson, 2019). Adult males are a glossy black colour while females and young males are dark-brown with white barring (Tipper, 2016, p. 77).
Asiatic Honeybee (Apis cerana): In a small crack in the rock face overlooking the water feature at Island House lies a natural hive of Asiatic honeybees. Distinguishable from the introduced Italian (European) honeybee (Apis mellifera) by its darker abdomen and narrower stripes (Yiu, 2005, p. 147–p. 148), this species also has a unique defense mechanism that its introduced counterpart lacks. When the hive is invaded by a hornet (a common bee predator), the bees will swarm all over it, vibrating their flight muscles to generate heat that ‘cooks’ their predator alive (Karacs, 2016). Sadly, it has no defense against diseases spread by European honeybees, leading to an 80 per cent decline in Asiatic honeybees across China since the 19th century. This decline may also have been further compounded by European honeybees invading the hives of Asiatic ones and preventing male bees (drones) from mating with the queens, another likely contributor to the break-up of colonies. This is worrying for the ecology of East Asia — while Asiatic honeybees can pollinate most of the plant species in this region, European ones can only pollinate a few (Chen, 2017).
Sea Slater (Ligia exotica): If you go for a stroll along the shoreline of Island House, one of the first things that may draw your eye is the sight of several tiny creatures zipping away over the rocks out of sight before you can get a close look at them. These are sea slaters, a primitive form of crustacean. They are abundant on exposed and semi-exposed rocky shores and have semi-flattened bodies that help them to hide in narrow crevices. Although they can survive in water, they prefer dry land and are usually found high up the shore away from the sea (Lai et al, 2006, p. 46).
Common Sandpiper (Actitis hypoleucos): Another, much less common animal one that may be spotted walking along the shoreline is the common sandpiper. Unlike many shorebirds of the order to which it belongs (Charadriiformes), it is a solitary animal that is just as at home on coastlines and wetlands across Hong Kong as it is on those of Deep Bay. It’s olive-brown upperparts provide good camouflage against the boulders, but as it is very active with a conspicuous, persistently bobbing white rear end, it can be quite easily spotted as it picks its way over the rocks in search of invertebrates and small fish (Tipper, 2016, p. 56; Lai et al, 2006, p. 75). It can also be seen flying low over the water with rapid, fluttering wingbeats (Tipper, 2016, p. 56).
Litchi Stinkbug (Tessaratoma papillosa): Given the presence of a lychee tree at Island House, it is perhaps not surprising to find the litchi stinkbug here too, as the sap of lychee and longan trees is a favoured foodstuff of this insect. It is most frequently seen in spring and summer, with large numbers often gathering on the same tree to feed, sucking its sap using special piercing mouthparts. But while it does have a beautifully patterned body, don’t touch it. It’s not called a stinkbug for nothing and when threatened, it produces a foul-smelling substance that can remain potent for several days afterwards (Fang, 2006, p. 35, p. 37).
References
· Chen, S., ‘Why China’s honeybees are losing out to their Western counterparts’. South China Morning Post, 9 April 2017, https://www.scmp.com/news/china/society/article/2083725/why-chinas-asian-honeybees-are-losing-out-their-western (Accessed: 15 July 2019).
· Ferguson, R., ‘What is that really, really noisy bird?’, Wild Creatures Hong Kong [web blog], 25 March 2019, https://www.wildcreatureshongkong.org/single-post/2019/03/25/What-is-that-really-really-noisy-bird (Accessed: 17 July 2019).
· Fang, H.J. 2006. Photographic Guide Series to Hong Kong Nature (8): Amazing Insect World. Jan KC Chan, HK Discovery Limited, Hong Kong. 35pp., 37pp.
· Karacs, S., ‘Asian hornet invasion: British beekeeper shocked to see Hong Kong bees boil thumb-sized foe using own body heat’. South China Morning Post, 13 February 2016, https://www.scmp.com/hkbees (Accessed: 16 July 2019).
· Lai, V.C.S., Lui, H.T.H. and T.C.W. Wong. 2006. Photographic Guide Series to Hong Kong Nature (9): Hard Shore Organisms — Rocky Shore and Boulder Shore. Jan KC Chan, HK Discovery Limited, Hong Kong. 46pp., 75pp.
· Tipper, R. 2016. A Naturalist’s Guide to the Birds of Hong Kong, John Beaufoy Publishing, United Kingdom. 56pp., 77pp.
· 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. 132pp.
· Yiu, V. 2005. Photographic Guide Series to Hong Kong Nature (6): Insect Portfolio — Hong Kong Insects (Volume 2). Jan KC Chan, HK Discovery Limited, Hong Kong. 147pp.–148pp.
