San Tau

You may see some Blues twinkling around. If you look carefully, they are Blues called “Quaker” (Neopithecops zalmora). The upper side and lower side of the wings of Quaker have very contrasting colours — the upper side is black and the lower side is white. When it flaps its wings, we can see its wing colours — black and white flashing in the air. Quakers always appear in groups, surrounding Glycomis, which is their caterpillar food plant.

Romerillo growing beside Tung Chung Hau Wong Bridge attracts many Blues, Whites and Yellows, like Long-tailed Blue (Lampides boeticus), Indian Cabbage White (Pieris canidia), Common Grass Yellow (Eurema hecabe) etc. Also, Tung Chung River is a highly ecologically valuable local river, where you will encounter numerous species of freshwater flora and fauna.

Kandelia is commonly found in tidal wetlands, and is the food plant for caterpillars of Chocolate Royal (Remelana jangala). Females like to lay eggs on this plant. Nearby Wild Bean is favoured by various caterpillars of Blues and Awls. This is also a good place to watch wetland animals, including fiddler crabs and mudskippers. Fiddler crabs spends much time in holes they have dug. Wait patiently if you want to see these lovely creatures.

You can find Chinese Hackberry on the right; this is the food plant for caterpillars of Red Ring Skirt (Hestina assimilis). Red Ring Skirt has black and white stripes on its wings, mimicking toxic Danaids. Thus, predators mistakenly think it is poisonous and dare not attack it. Male Red Ring Skirt has strong territorial behaviour. It often stays high in area to guarding its territory.

King Snake Creeper can be found along both sides of river. The plant is the food of caterpillars of Red Lacewing (Cethosia bibles). The butterfly is orange red. The wings have serrated edges, and black and white stripes. You can also find a ghost face pattern on its wings! Slow down here to look for this interesting butterfly.

Lance-leaved Sterculia can be found here. It bears orange red star-shaped fruits in summer, like stars on the trees. The fruits are used in celebrations for Seven Sisters Festival, so are also known as “Seven Sisters Fruit”. It’s the caterpillar food plant of Short-banded Sailer (Phaedyma columella). This Sailer’s wings are black, with three distinct white stripes. It loves landing on leaves and spreading its wings for sun bathing.

You may find some plants with bizarre red flowers along the footpath. They are Uvaria and are caterpillar food plants for Five-bar Swordtail (Pathysa antiphates) and Common Jay (Graphium Scopoli). Five-bar Swordtail has a long tail on its back wings, like a sword. It flies swiftly. Watching it is not easy!

During weekends and public holidays, many hikers often gather at the stall to rest. When you look around, you can find lots of nectar plants including Lantana and Blood-flower Milkweed, which attract large numbers of butterflies coming for nectar. You can easily spot Swallowtails and Birdwings, like Lime Butterfly (Papilio demoleus) and Paris Peacock (Papilio Paris), in this area.

Choosing the middle footpath will lead you to the junction of Tung O Ancient Trail and the river. White Dragontail (Lamproptera curius) and Baron (Euthalia aconthea) have been recorded here. White Dragontail is listed among the Class 2 Protected Animals of the PRC. Illigera, the food plant of caterpillars of White Dragontail, is protected by Hong Kong legislation. Part of White Dragrontail’s front wings is colourless, and its back wings have very long tails, which look like a swallow’s tail. It is the smallest Swallowtail in the world, with a wingspan of just around 4cm. Pay more attention to the surroundings if you want to see it!