On one or two bare patches of soil I came across quite-fresh kangaroo scats. Just 30 minutes later, returning to that same area I found a young male kangaroo, took his photo and moved away from him. Wouldn’t it be great if we could have a small mob to keep the wild oats and rank introduced grasses in check and thereby reduce the summer fire-risk? Solutions are not that simple, of course, and I expect sightings such as todays are the result of the individuals being separated from Dunlop or CSIRO mobs.
Some years ago on a sleety, wintry day I was surprised to find a small flock of Varied sittellas foraging just west of the two tanks. On 27th June I came on another group of these small birds giving our trees a ‘going-over’. With distinctive yellow legs and quite short tails the sittellas glean insects from the barks of trees but tend to travel down the trunks and branches as they do so whereas tree-creepers move upwards. Sittellas are listed as a threatened species in the ACT so we’re lucky that they visited.
They were accompanied by other species of small birds including Double-barred finches. Seeing these little birds was another “buzz” as I’ve not seen them around or heard their “mewing” call for many months though I class them as residents. Scarlet robins are with us for the winter months. There was a pair in the flock, characteristically dropping down to the ground to grab insects and then flying back up to a bare lookout-branch. There are pairs of Golden whistlers with us now also.
April is usually the time for the traditional Honeyeater migration out of the ACT with thousands of birds flying to warmer places. Sites along the Murrumbidgee corridor serve observers well but it’s common to see small flocks moving through places like Mt Rogers. Even Red Wattlebirds gather and migrate but many remain to be the dominant species in many gardens. Some White-eared and Yellow faced honeyeaters over-winter around Mt Rogers and with Silvereyes and sometimes our resident Wrens form the core of ‘mixed’ feeding flocks to host visitors like the Sittellas.
Mixed flocks allow different species of small birds to forage in safety. Each species has its own niche of preferred insects or seeds. Old, scruffy and prickly trees shelter these birds from predators such as Currawongs. There was a raptor with what could have been a feathered victim in its talons on 28th. Perhaps it was a Brown goshawk with a Silvereye.
Dense shrubs and established bushes in nearby gardens are also essential shelter and sources of food for foraging native birds. The instinct is to request gardeners remove berried weeds from their gardens but in tough times the invasive plant species do provide food. Pruning such shrubs after flowering does reduce the number of berries available for dispersal into the bush, but, of course reduces the colourful display of winter berries that, I assume, owners enjoy. It would be interesting to know how far berry-eating species travel before depositing their load of potential-weeds. Or, in other words, how far away do gardens have to be from “the bush” before they could be said to be innocent of providing the next delivery of weeds’ berries.
You’ll have noticed that many birds seem to eat all day in order to have enough ‘fuel’ for their daily life or moving around. Birds such, as Sulfur-crested cockatoos, are large enough to have ‘time-to-play’. Have you seen them creating the carpets of prunings under flowering eucalypts by ‘chewing’-off the branches with their powerful beaks? Does this destruction damage the trees or affect the nectar-supplies for honey-eaters, bees and other pollinators?
Most Eucalypt species show enormous resilience. As we saw after the 2003 fires, many species developed new branches from epicormic buds underneath their bark. There are also examples of trees re-growing from lignotubers or adopting this epicormic regeneration process on ‘the hill’. Presumably blown over by capricious winds one or two trees now have horizontal trunks but enough roots remaining in the soil to bring water up for the leaves on vertical branches. Perhaps, in refusing to die, they’re shaped like giant toothbrushes. They certainly add to the diversity of trees’ form and Mt Rogers has a wealth of arboreal sculptures! It would be hard to capture the wonder of barks’ rain-wetted colours from a conventional paint-box. Photography, at least, can record that and the barks’ textures.
Rain stimulates another showing of resilience when mosses, ferns and lichens ‘come-to-life’ once the air is moister. Lichens hydrate and rejuvenate their special colours on rocks, bark, soil and fallen litter. According to Wikipedia lichens demonstrate helotism, a relationship whereby ‘fungi enslave algae’. The association of the two organisms produces lichenic acid which etches rocks. This etching has the effect of wearing-away rock so that plants such as mosses can take hold. There’s also a soil-building effect and lichens growing on bare soil bind the surface particles together, preventing erosion.
A ‘cross-country’ walk brings rewards of seeing clusters of lichen-covered rocks and noting the plants which benefit from growing near them. Urn heath has pale yellow ‘heather-shaped’ flowers for most of the winter months. It’s found near several boulder clusters around Mt Rogers. Less common are the Cryptandra bushes with tiny white buds gradually opening from August onwards. These two species have slightly woody stems which reach knee height. Rock ferns hug the rocks even more closely seeking the moisture than runs off the surfaces and the cool but constant temperature underneath for their roots. In the burnt area there are many young Rock ferns but it is the older ones which are fascinating in their ability to change after rain. The heat of summer appears to shrivel their fronds into brown, almost-skeletal twists and yet they appear to green up, in a matter of hours if rain falls or as autumn brings more regular moisture. One particular group of rocks hosts a group of 13 Barbed-wire grass clumps. They are named for the shape of the flower-heads and I remember being amazed when I first found them because as I approached I expected the rust-coloured plants to be the comparatively commonplace Kangaroo grass. Three clumps of BWG were planted 2 years ago and another three are waiting to be planted up there when the soil becomes damp enough.
As we all realise once we’ve become addicted to walking amongst Mt Rogers’ plants, animals and features there is always something to marvel at and hypothesise about. What other signs of spring will be noticed over the next two weeks? Which birds will be nesting first (a magpie was recycling soft material from a fallen nest yesterday)? A large, delightful group of Silvereyes enjoyed Privet berries whilst I watched them this morning…whose garden will those weed-seeds end up in? Do some animals eat weed seeds and destroy them in the process or do the seeds remain viable in spite of their digested journey?
Why do some small numbers of species like Barbed wire grass and Indigofera survive against the odds? Are the Hoveas in flower already? Will the Frogmouths nest where we can see them this spring? What happened to the Speckled warblers? Were they and the Quail eventually taken by foxes or residents’ cats? Has anyone seen Echidnas in recent months?
Sometimes our questions can be answered by browsing books but the Internet is an invaluable tool too. Canberra Ornithologists’ Group’s website has a photo-gallery where members’ photos help with bird identification. www.canberrabirds.org.au and www.birdsinbackyards.net is also useful. Local plants are illustrated by the Australian Botanic Gardens website’s photographs.
On a slightly different tack and for those of you with water-features, the Ginninderra Catchment Group has produced a free, excellent large poster of local frogs. If you would like a copy or know who would, phone them to arrange collection from their office at Kippax 6278 3309.
If there are issues about Mt Rogers that you wish to raise with ‘the Government’ then contacting Canberra Wickens Place
No comments:
Post a Comment