Giving koalas a new home

Koala climbing tree
Koalas and their trees cling to life and could need our help

Yinnar/Yinnar South Landcare

By Jay Duncan,

Koala food trees need support staff, especially if they are old or infirm

Our group has seen a lot of interest recently in planting koala food trees. To be pleasing to the koalas, and to keep the trees flourishing, new habitat areas need to include understorey and to be mindful of the health and support needs of the eucalypt trees.

In many areas of Australia there has been a major loss of eucalypt trees that has happened suddenly, frequently in the local dominant species. Koalas only eat eucalypt leaves.

Concerned Landcare Groups, farmers and conservationists have sometimes been able to slow or prevent further decline of some eucalypt species.

They do this by excluding stock and planting a lot of other species around any remaining old, unwell or isolated eucalypt trees. Some people are bringing in some of their seed from the warmest part of the species’ range to try and protect against a warming local climate.

By increasing local biodiversity these actions can have many other benefits for surrounding areas in addition to saving eucalypt trees.

Some things that are needed to help the remaining eucalypts to survive are:

From the bottom up:

Soil fungi for the trees to be able to take up nutrients. Vast subterranean networks of fungi feed the trees which can’t take up nutrients directly. Urine from stock sheltering under the few remaining trees in their paddocks will eventually kill the fungi and then the tree. Excluding stock and allowing some fallen timber and leaf litter to remain on the ground will allow any remaining soil fungi the best chance to flourish.

Venerable Fallen Tree
Venerable old tree sadly laid low by grazing and trenching

Slicing through the roots and/ or continually driving under trees is harmful. Pipes can and should be bored under the centre of valuable trees rather than put in trenches sliced through the root system.

Things that live in leaf litter and fallen logs such as lizards will help to manage the balance of insects and stop the trees getting suddenly attacked by unnaturally large numbers of beetles or caterpillars. (Gum trees can survive most insect infestations. Please do not use insecticides.)

Still on insect patrol, understorey vegetation will provide food for invertebrates and shelter and nesting sites for insectivorous birds which help with insect control.

Getting bigger.

If isolated trees or vegetation patches can be linked with other native vegetation, the night patrol can move in as the under storey trees get bigger. Possums, gliders, micro bats and flying foxes provide services to trees that include pest control and pollination. Eating their natural foods apparently delivers a contraceptive effect for possums – so your garden might also benefit.

Spotted Pardalote
Spotted Pardalote In wattle heading for creek bank nest
More pollinators.

Australia has many more species of flowering trees than virtually any other part of the world, and we have a whole lot of honeyeaters that have evolved to pollinate these plants – and often to fight with each other for the territory. They feed in the trees but nest much closer to the ground. Help them by keeping cats indoors, planting prickly shrubs and trying to control foxes. They also need insects to feed their broods and spiders’ webs to line their nests – so, once again, please tolerate a few bugs and lay off the pesticides.

The smallest and cutest of all birds, in my opinion, are pardelotes. They are classified as flowerpeckers and live in the outer canopy of trees. These and other birds feed on lerps which are another tree parasite that can get out of control and kill weak or isolated trees.

They do, however come down to ground level to breed and are especially vulnerable at this time. Spotted pardelotes nest in burrows in creek banks or drains.

Koalas also need to move into understorey trees for shade and shelter when the weather in the canopy doesn’t suit them.

Powerful Owls
Powerful Owls need tree hollows to breed and roost
in the understorey during the day

Next month: Some local acacias (wattles) to plant in your understorey.

Mark Adams at Swinburne University of Technology has measured the amount of wood laid down by various species and the amount of water required by them to do so. A champion genus is acacia. It produces far more wood for a given amount of water than other plant, and acacia species are quick growing. (The Science Show, Radio National)

Our Landcare Group can take orders now to grow: blackwood, silver wattle, black wattle, hop wattle, narrow-leafed wattle, varnish wattle and prickly Moses as well as most local eucalypt species and other understorey plants..

Secretary, Yinnar, Yinnar South Landcare Group 5163 1393