Western Grey Kangaroo, Macropus fuliginosus

Kangaroos are an Australian icon and our best-known marsupial.

The two legged hopping type ancestor of present day kangaroos evolved in Australia around 8 million years ago, prior to that all marsupials walked on all fours. However marsupials have a long evolutionary history with the earliest known fossil dated to around 125 millions years ago (long before the dinosaurs disappeared). Now you may think that these fossils were discovered in Australia, but you would be wrong; they were discovered in China. The Australian line of marsupials are relatively late with the earliest known fossils only 55 million years old. It is thought that they had moved down via South America, into Antarctica during the warmer Gondwana period and then into Australia.

Around 15 million years ago, maybe due to climate change or the rise of placental mammals (the ancestors of cats, dogs, horses, cows and even us), the marsupials in most other parts of the world went extinct, leaving the island continent of Australia their remaining stronghold. A few marsupial species still survive in North and South America, plus Paupa New Guinea but none compare with the diversity of our marsupial fauna.

Mum and joey of the Western Grey Kangaroo, Macropus fuliginosus. The female joey will often remain with her mother long after leaving the pouch (over 2 years), even giving birth to a joey herself.

The Western Grey Kangaroo (Macropus fuliginosus) is very similar to the Eastern Grey Kangaroo (Macropus giganteus) and was considered to be the same species for over 100 years. Of the differences between them, the most obvious is their fur color, the western greys being much darker and brown in color, whilst the eastern greys are in fact, more grey. The eastern grey is also slightly larger (reaching close to 2 metres in height), although not much larger than the westerns. Mature males of both species are noticeably bigger than the females.

The western grey's territory extends from the west coast of WA, right across the southern part of the continent into western NSW, Victoria and southwestern Queensland, preferring the more arid zones. Interestingly all the kangaroos on its namesake, Kangaroo Island in SA, are western greys. Eastern greys occupy parts of Tasmania to northeastern Queensland and just entering eastern SA, preferring the higher rainfall regions (above 250 mm a year).

The eastern and western grey kangaroo territories actually overlap in SA, NSW and Qld, but they are not known to interbreed (although in captivity they can). Other obvious differences is in their behaviour, with the western greys keeping to small family groups, whilst the easterns often collect in large mobs of both genders and different ancestry.

A small western grey kangaroo family group of mum, dad and junior.

Possibly due to habitat, these two kangaroo species have slightly different diets. The eastern greys preferring grass and soft herbaceous plants, whilst the westerns greys tend to consume more roughage gained from a variety of shrubs and even tree bark. The dietary requirements of the eastern greys has put them into more conflict with farmers, as their prime grazing areas have been taken over for agricultural purposes. Whereas the more arid living western roos can often cohabit with domestic stock on large rangelands. Also due to their drier habitat, the western greys have a lesser need of water, gaining most of their moisture from what they eat.

Interestingly, western grey kangaroos sexually mature (by several months) earlier than the eastern greys, allowing depleted populations to re-establish more quickly. The male of this species has the derogatory name of 'stinker' because unlike the eastern grey, it develops a strong unpleasant curry-like odor upon sexual maturity. Generally grey kangaroos in the wild live for around 10 years, but this time span can be doubled when kept in captivity, such are the high stress levels and other hardships of a large herbivore contending with drought, predators and human restrictions.

A pair of western greys getting their roughage from a heath habitat.

By hopping, rather than running on four legs, the kangaroos have actually developed a very efficient means of locomotion. To hop faster, the kangaroo simply maintains a similar number of hops per minute, but simply increases its stride, also it recycles up to 70% of the energy used, we on the other hand can only recycle around 20%, so they can maintain high speeds for lengthy periods. I have clocked grey roos effortlessly doing 45 kilometres per hour over several kilometres. Yet another advantage of hopping is it aids breathing; when landing air is expelled from the lungs and when jumping, air is automatically drawn into the mouth. So kangaroos are very well adapted to living in open semi-arid rangeland, grasslands or open woodlands.

From time to time there is speculation that the grey kangaroo is endangered; this is certainly not the case as both species occur in their multi-millions. However, the eastern grey kangaroo although still very numerous are probably less so due to their grazing areas being utilised for farming activities, but they are far from being a threatened species and can occur in plague proportions in favoured undisturbed habitats. Still, I think we are very fortunate to have such a large uniquely Australian animal that can survive in most bush habitats and often in close proximity to human occupation. These kangaroos are so common that many people have a very indifferent attitude toward them and often consider them vermin, nevertheless we and the world would be worse off without them and we should cherish and foster their well-being.

Mum and a very cute joey playing hide and seek.Western Grey Kangaroo, Macropus fuliginosus

Honey Possum, Tarsipes rostratus

It is cute, but not a possum, nor does it eat honey.

The Honey Possum split from the glider and ringtail possum linage around 2 million years ago where upon it underwent rapid evolutionary change to become the sole member from the Family Tarsipedidae. Honey possums live almost exclusively on a diet of pollen and nectar (not honey, only bees make honey), and hence only survive in regions where nectar producing blossom are available year round. This only occurs in the SW of Western Australia (comprising the region known as the Wheatbelt) extending from Israelite Bay on the south coast, to the Murchison River on the west coast. Due to extensive clearing of vegetation in much of the inland mallee region for wheat production, its stronghold is on the coastal sand belt, much of which remains reasonably intact.

A very thoughtful little honey possum in an Adenanthos cuneatus shrub.

Honey Possum, Tarsipes rostratus

The honey possum is tiny, being smaller than the mouse, Mus musculus and weighing half as much. Their eyes are unusual, inasmuch they do not reflect torch light like true possums, so are very difficult to find amongst the dense foliage of the predominantly Proteaceae plants on which they feed. However partly because of their small size, they hold a couple of world records; apparently the males have the largest mammal testes in relation to their size (around 4.2% of their body weight), but surprisingly they also produce the largest sperm (to 0.36 mm in length). Not to be outdone, the female then produces the smallest young of any mammal, weighing only 0.0005 gm. So a very remarkable little animal and of great interest to the scientific community.

As an indication of size, that Banksia speciosa flower is 150 mm in height

Contemplating its future in a Banksia nutans shrub.

The long slender snout, houses a long slender tongue with a brush-like tip for reaching and lapping up the nectar from the generally long slender tubular Proteaceae flowers. Due to this adaptation it is thought to be an important pollinator of many Banksia and other Proteaceae species. The honey possum has teeth, but they are very specialised, the lower fangs are designed (along with groves in the palate) to scape off the nectar/pollen from the tongue, whilst the other teeth are tiny, peg-like, widely spaced and totally ineffectual for eating solids. However in captivity honey possums are known to eat soft-bodied insect larvae.



Females are about a third larger than males and occupy the dominant position in any relationship. However they generally lead a solitary life, but with overlapping territories, remain quite sociable with others except when the females have young. Their life span is between 1-2 years, but they breed year round providing there is sufficient food. I encountered a mum with two young sitting along side of her, they were only 600 mm away, stationary and in an exposed position ideal for photographing, but they looked so terrified that I returned my camera in its box and left them undisturbed.

Female honey possum about to disappear into an Adenanthos cuneatus shrub.

Honey possums are great climbers, but unlike most other mammals, they do not use their claws, but grasp branches like a monkey with opposable toes. Its genus name of Tarsipes, is derived from the Tarsier (a primitive primate, with a similar foot structure). The honey possum also has a prehensile tail that can support its weight, so is very agile and well adapted to its arboreal home. When caught by torchlight, it usually freezes and remains so unless you come too close, when it can move very quickly. I even had a fleeting glimpse during the day of one (probably disturbed by a bird or reptile) moving over the ground from one bush to another, it was very fast and with a mixture of galloping and leaping, it soon disappeared.

Typical rusty brown stripes and long prehensile tail of the honey possum.

Although this tiny animal is known to climb high into Banksia trees to reach the blossom, I have only seen them within 2 metres of the ground and usually only between a ½ and 1½ metres. Being above this height on the terminal Banksia speciosa flowers, places them in considerable danger of predation from night birds like owls and frogmouths, and when at lower elevations from cats and foxes. I have encountered dead honey possums (and pygmy possums) that had been caught and mauled by cats, and have watched a fox so intent in tracking one down in a clump of low Banksia pulchella, that I almost caught it in my hands.

The reason I suspect the honey possum does not feed from lofty exposed Banksia flowers, is the Tawny Frogmouth, Podargus strigoides, who will happily dine on frogs, reptiles, moths and honey possum.

According to my Jack Russell Terrier (who is under very strict orders not to hunt them), the honey possums do give off an odor, but it is disguised by the odor of the Banksia flowers, and fortunately they take a while to track down, nevertheless the dog is aware if any are around, so presumably cats and foxes would too. I dare say birds and reptiles also take a few, therefore not only are they endangered from predators, but equally so from land clearing and devastating wildfires.

Honey Possum on a Banksia speciosa flower.

Wildfires are caused when the native vegetation is permitted to grow for many years without periodic burn-offs (partly to reduce fuel loads); such fires are highly destructive particularly to the fauna. However if the preferable indigenous mosaic fire management were employed, then it would by its more open flora composition, advantage predators like the cat and fox, by leaving the honey possum more exposed and consequently more easily caught. (see item 14. Fire Management: European versus Indigenous). http://natureitems.blogspot.com.au/2006/12/fire-management-european-verses.html

From studies conducted in the Fitzgerald River National Park (200-300 km west of Esperance), it was concluded the honey possum did best when fire frequency was at least 20 years apart, in order to permit the floral community, particularly the Banksia species to mature. The situation in the Esperance region I believe is quite different. There are four plant species I have seen the honey possum using and they are also the most dominant in Esperance sandy heath. They comprise the largest local Banksia, B. speciosa that grows to around 6 metres and flowers May to Jan. Banksia nutans to around 1½ metres (flowering Nov to April), and Banksia pulchella usually less than 1 metre and commonly only ½ metre in height (flowering Jan to Oct). The fourth plant and another Proteaceae also very popular with the possum, is Adenanthos cuneatus, which has a very long flowering period, doing so off and on throughout the year. This can grow to 2 metres in height.

With some exceptions, after 20 years, the three Banksia species mentioned would be pretty much at the end of their useful life, with B. pulchella being smothered by larger vegetation, B. speciosa beginning to die off and B. nutans just hanging on. The Adenanthos would be incredibly leggy by this stage (if not smothered) and like the rest, not producing much blossom. However, all of these species would be flowering within three years of a bushfire, and with more blossom than an army of honey possums could consume by 5 years. Most of the largest plants Banksia speciosa and B. nutans would be at their peak (blossom wise within 15 years and beginning to deteriorate thereafter), the others deteriorating within a much shorter period.

Having said the above regarding the Esperance (honey possum) flora situation, I return to the concluding statement of the Fitzgerald River study, where it was found that honey possum numbers were at their highest 20-30 years without a bushfire. This may well be the same for Esperance, but not for the number of nectar producing blossoms available, but from the dense (overgrown) vegetation that is providing protection from cat and fox predators. As a cautionary note, the entire possum population can also be wiped out by a wildfire derived from this overgrown environment with its very high fuel load.

What I believe to be a sensible solution as long as the fox and feral cat populations remain high, is to provide pockets of aged vegetation, alongside areas with a mosaic of different aged flora. However the situation I regret will not improve to where the honey possum is secure in its native environment, unless predator numbers are substantially reduced.

An easily hidden, yet highly vulnerable honey possum.