A staggering 75% of the south west’s 7000 species of flowering plants are found nowhere else on earth? So be prepared to see plants that you have never seen before if you walk this track. One of the main understorey plants through here is karri hazel (Trimalium ordoratissimum). It usually grows in dense thickets as a large shrub, up to 9m high. Its small flowers are massed into large delicate creamy-coloured sprays. The Aboriginal people call this the soap tree and used it for washing as it lathers well. They also used to place it over ponds of water, drugging animals that came to drink and hence making it easier to catch them.
Peppermint trees (Agonsis flexuosa) are common in many coastal areas on this track. They form thickets or open groves, and range from dwarf in coastal areas to tall trees away from coast. Tufts of white flowers adorn pendulous branches in spring and summer. They are arranged in tight spherical clusters. The leaves have a strong peppermint smell when crushed. The bark is thick, grey and fissured. They are an important habitat for the endangered ring tail possum that feeds on the leaves and build dreys (nests or platforms) in the branches. Peppermints are extensively planted as a street tree in Western Australia.
There are lots of karri trees (Eucalyptus diversicolor) along the track. Karri is one of the world’s tallest hardwoods and WA’s tallest tree. They can live for 300-350 years and grow up to 90m tall, reaching their full height after about 75 years. They have pale grey peeling bark reveals smooth pink, orange, brown trunk hues. The karri’s surface bark is shed every year during summer and autumn, exposing new bark that is pink and cream coloured. Aboriginal people knew that when the bark of the karri dropped, this was the time of year when ocean salmon (perch) were running. There are relatively few upper branches arranged in distinctive “broccoli” shaped clusters. The botanical name “diversicolour” means “separate colours” and refers to the difference between the two shades of green on the leaves – strong green on top and grey green below.
On the walk out of Walpole you’ll see tingle trees, particularly red tingles. There are three types of tingles – red (Eucalyptus jacksonii), yellow (Eucalyptus guilfoylei) & Rates (Eucalyptus brevistylis).
The red tingle can be identified by its rough fibrous bark of a grey-red colour. Only found near Walpole and Nornalup, this tree has an extremely restricted range. It can only be found in an area of approximately 6,000 hectares. People have tried to grow them elsewhere but been unsuccessful.
Red tingles are named for their distinctive red wood. They can reach a height of 75 metres and grow for over 400 years. They are known for their large trunks, which can have a circumference up to 20 metres. They are the largest buttressing eucalypt. Swaying in the wind stimulates growth of the tree’s lower trunk and roots which broaden outward in the shallow soil to stabilise the tree like angle brackets.
The distinctive feature of the red tingle is its large, hollowed out base. The hollows have been caused over a long period of time by fire, fungal and insect attack. They can survive with these hollow bases as the wood is very strong and even a thin shell will support the tree – as long as part of the living layer of the tree immediately under the bark remains intact, the tree will re-shoot and continue to grow.
Jarrah (Eucalyptus marginata) is the state’s most important commercial timber. It’s also one of the most common trees in the south west. Marginata refers to the thick margin around the leaf’s edge. It’s a tall tree growing to 40m. It has grey, fibrous, striated bark, often twisting up the trunk. The bark sheds in long flat strips. The richly coloured and beautifully grained timber is used for flooring and cabinet making. And, in the early days of European settlement, some famous roads in cities such as London and Berlin were paved with blocks of jarrah.
Marri (Corymbia calophylla) is a tall tree with twisted branches, chunky tessellated bark, oozing resin and broad dark green leaves. One of the most noticeable things you’ll see is the large gum nuts lying underneath the tree. They are bell shaped and about 2 – 3cm long and are locally called “honkeynuts” fruit. Take care as they are easy to trip up on! These nuts are the largest fruit of any eucalypt and they are a very important food source for a range of parrots and cockatoos. They inspired May Gibbs to write her stories about gumnut babies, Snugglepot and Cuddlepie. They have recently been reclassified and are now no longer considered to be Eucalypts.
The sheoak trees (Allocasuarina decussata) have very deeply rutted bark, making them easy to identify. They are also called karri sheoak and are in the Casuarina family. When cut across the grain, early settlers thought it resembled oak from back at home but of an inferior quality, hence they called it “she” as women in those days were considered inferior!
There are lots of grass trees (Xanthorrhoea preissii) and kingias (Kingia australis) on the southern Bibbulmun. They might look similar at first glance but check out the flower spikes and you’ll spot the difference. The grass trees have long straight flower spikes that usually point upwards and kingies have lots of short stemmed flowers with a ball shape on the end, clumped in a ring.
This southern area of the track also contains the restricted, rare and spectacular red flowering gum (Corymbia ficifolia). It used to be called Eucalyptus ficifolia but was reclassified recently. It’s the only place it occurs in the wild. It flowers between January and March and has blossoms ranging from scarlet red and crimson to orange and pink. It is a small tree, growing to about 5m in height, which resembles a small marri with similar leaves and knobbly bark. Seed was originally collected here for nurseries throughout Australia and overseas.
Bull Banksias (Banksia grandis) are common in the understorey of jarrah forests. They have enormous leathery leaves that are quite distinctive as they are deeply divided into numerous large triangular lobes (saw-toothed), as well as very large golden yellow flowers in spring and summer. Candle Banksias (Banksia attenuata) are a tree that has numerous slender cones of bright yellow flowers in spring and summer. They have leathery strap-like leaves with finely serrated edges. Holly-leafed Banksia (Banksia ilicifolia) is not immediately recognizable as a banksias. It has short holly-like leaves, and the flower cluster is more like a ball shape.
Black cockatoos are red-tailed, white-tailed or yellow-tailed. Yellow tailed are not common. If you see a black cockatoo, look a little closer to see the colour of the underside of its tail. If there are red panels then it’s a red-tailed black cockatoo. If the underside of the tail is white, it will be one of two species of white-tailed black cockatoo – Baudin’s cockatoo or Carnaby’s cockatoo. Baudin’s has a long and narrow upper bill whilst the Carnaby’s is shorter and stouter.
Other birds you might see on this walk include, western rosellas, red winged fairy-wrens, black-faced cuckoo-shrikes, golden whistlers, splendid fairy wrens, white breasted robins, scarlet robins, spotted pardalotes, white browed scrub wrens, ring-neck parrots, red-eared fire tail finches, purple-crowned lorikeets and crested shrike-tits.
The beaches along this coast are home to many seabirds. Seabirds utilise the energy of the westerly gales in this area, known as the Roaring Forties. The yellow nosed albatross and the Australasian gannet are regular visitors to these shores. These birds rely on the wind for their survival – they cannot fly low across the waves nor cover the vast distances they travel without it.
As you are walking along the Bibbulmun you’ll see many skinks (tiny lizards) darting about all over the place. They will often freeze on the track if surprised by walkers, in the vain hope that their camouflage has worked and that you can’t see them! If they are being chased by a predator such as a bird, they are able to drop the end part of their tail off. The predator is usually happy as it gets at least something to eat. The skink can then grow a new tail.
Whales can be seen during winter & spring. Humpbacks are the most acrobatic of whales and often display breaching, spy hopping & tail slapping. They have a dark body, a dorsal fin (i.e. the one on their back), a characteristic “hump” back and rarely exceed 15m in length. From about late April to early May they leave Antarctica to migrate northwards to their tropical calving grounds along the west and east coasts of Australia. About August they begin heading south to their feeding grounds in Antarctica where they feed on krill, so the first whales can be seen here from early spring. They often travel in large pods of 200 or more. They are filter feeders, straining their food from the water by hundreds of horny baleen plates hinged on their upper jaws. A humpback can eat about one tonne of food a day so they feed where there are large concentrations of krill. Whaling of humpbacks ceased in 1963 and since then the whale population has steadily increased. Several thousand pass this way every year.
The Southern Right whales hang around inshore for months. They are the rarest of the large whales and grow up to 17.5m long. They are easy to identify as, unlike most whales, they don’t have a dorsal fin. They move slowly, have large callosities (horny growths) on their large heads,
and are commonly seen close to shore, often looking like a floating log. They were so named because they were the “right” whale to harpoon. For a bit of trivia, they have the largest testes and penises of any living thing! Whaling of Southern Right Whales ceased officially in the 1930s but illegal catches until about 1970 prevented their recovery until then. About 200 visit the south and west coast of Australia each year.