In the pre-development days graziers would have paid good money for these grasses’ seeds and oats to improve pasture for their stock. Did they also spend money and countless hours on clearing the area of trees? They may have been told trees steal nutrients and water from the grasses their sheep & cattle needed. Rewards were available for cleared land in many states and jurisdictions. It’s quite sobering to visualize the hours of toil felling and ring-barking required and then reflect that these policies have begun the degradation and salination of countless hectares of Australian land.
Photos from the seventies show Mt Rogers as mostly open and treeless and supporting tall grass and thistles. Forty years on we resent these introduced grasses because, in good years, they grow tall enough to be a fire-hazard and might mask the presence of snakes which are a hazard to inquisitive dogs and unprotected legs. Although I saw three this week, there aren’t enough kangaroos to graze the grasses on Mt Rogers but, by autumn, the tallest, most healthy-looking grasses are native species…..Red grass, Weeping grass, Spear grass and smaller pockets of Kangaroo grass.
After overnight rain I donned wet-gear and gumboots and went cross-country too.
A certain, now deceased, ash tree offered a fine example of winged seeds having blown away from the parent plant. There are dozens of small ash seedlings amongst the grass. The seed that germinated to become the older tree may have blown in from a street where other, perhaps unwise; policies generated the planting of introduced trees without anticipating that their seeds would spread beyond nature strips. More encouragingly there were also seedling eucalypts doing well amongst the Weeping grass and several native Hop-bushes.
This partly illustrates the point some land-carers make that the bush will re-generate itself given favourable conditions. Of course it helps, and feels good, to give it a hand through weeding-out introduced species and planting, Years ago I discovered seven specimens of Indigofera adesmiifolia in seven different parts of Mt Rogers. I planted a few extras and they seem to be doing well, as do most of the plants the Guides put in in August 2010. Before the Guides planted we had to have both the proposed sites and the proposed locally-sourced native species checked for suitability.
The woody, environmental weeds we focused on for the working-bee on Sunday 10th show the down-side of leaving the bush to its own devices. Parks, Conservation and Lands did some productive removals about five years ago in the south-east of Mt Rogers but since then Privet, Cotoneaster, Hawthorn, Ivy, Periwinkle, and Pyracantha have grown from berries brought in from suburban gardens.
Four Conservation Volunteers Australia volunteers, with Ken as their leader and six Mt Rogers carers (Sue, Anne, Christine, Pamela, Helen and Bob apologised) used loppers, saws and glyphosate to spoil the introduced plants’ seeding chances. Four trailer-loads of berried branches were removed for high-temperature composting at Canberra Sand & Gravel by Chris and Denis. Kirsty abandoned visitors to arrive later bringing new energy to our effort. Barbara and Berlinda also multi-skilled by providing delicious home-baked fare to enhance morning-tea.
Anne had previously worked on Chinese pistachio and I made a start on a dense thicket of Broom whose seeds may have been brought by ants from a garden 50 m away. Because they have no natural predators here all these plants out-compete native vegetation for space, light, nutrients and water. They were given out as free-issue plants in the seventies until it was realised their berries were being taken into the bush (or others’ gardens) by birds. They proved useful as quick-growing screen plants and for hedges but those who’ve inherited them now face the task of removing them or making the annual effort to cut back the flowers or immature berries to reduce the weeds problem.
One of the signs of approaching cooler weather recognised by generations of Canberrans is the caroling calls of Pied Currawongs. Fifty years ago the birds used to return to the suburbs from breeding in the high country. Their behaviour has changed in response to the availability of the environmental weeds’ berries. The Currawongs were able to stay all-year with these supplies and when the berries were finished the birds also changed from supplementing their diet with Sparrows and Starlings to preying on the eggs and young of Fairy-wrens, Thornbills, Willie wag-tails and Honeyeaters. I read somewhere that one pellet regurgitated by a Currawong contained 60 Privet seeds. One pair of Currawongs may kill 40 broods (up to 2kg) of small birds to raise one brood of their own. You’ve probably noticed that Crimson rosellas and Silvereyes also enjoy Cotoneaster berries. This just adds to the complexity when appealing and attractive birds play a part in the negative cycle of weed dispersal. We prefer to ‘blame’ the big-guys.
There were several honeyeaters “up there” this morning making their specific contact calls. Honeyeaters are a very numerous group of birds and include Wattlebirds and the dizzyingly-fast Eastern Spinebills currently active in our gardens. In a bird book or on the COG* website’s gallery you’ll see that their beaks are ideal for probing into flowers. They have brush-like tongues for extracting the nectar offered by the plant in exchange for pollinating services. If you hear calling flocks of small birds passing through the Mt Rogers trees they may well be migrating groups of honeyeaters passing through towards warmer places for over-wintering. Yellow-faced honeyeaters were the most numerous this week.
It’s a good time to check out “mixed-feeding-flocks” of small birds. There may be several species feeding in the same area but using each other as look-outs in case of danger from raptors. Keep an eye out for Robins, Whistlers and several Thornbill species in these flocks. Grey fantails may seem to swoop very close but they have learned that we disturb insects as we walk and they seize the chance to capitalise on our exercise-routines. Perhaps fanning their tails also stirs up insects. Their aerial ballet is delightful to watch as they sally-forth from a branch after insects they’ve seen.
Tuesday morning was even better as there was an unperturbed mixed-flock on the edges and above the gully. There were Red-browed finches in the mix, sometimes eating fallen Paspalum seeds from the path. In the shrubs White-browed scrubwrens were concentrating on insects and probing under any lift-able bark. I have very few records of this species for Mt Rogers and I’ve not regularly found ‘Red-brows’. I moved on to the mountain-bike track south of the second summit. Work has resumed on refinements including moving soil and using a chain-saw to cut fallen timber. You may be pleased to know the ACT Government has employed consultants to examine tracks and trails within Canberra Nature Park
A consternation of Currawongs alerted me to the flight of a large brownish bird which alighted in a tall wattle just below the ‘second-summit’. It was, I think, a juvenile Brown Goshawk. It was very watchful but the resentful Currawongs only flew ‘so’ close. After some minutes I realised the raptor had a small bird in its talon as it would pluck out a few feathers from time to time. Eventually all moved off and the cacophony flew away. Luck places birdwatchers at the scene of the action, sometimes, but the little bird’s genes won’t be passed on.
I hope you’re out early enough these mornings to catch the effects of misty dewdrops on cobwebs. Such beautiful decorations show there are far more spiders around, playing their essential role in ecosystems, than we realise. If 1) you want to watch where your feet are going there should be several species of fungi emerging from the ground or leaf-litter whilst the soil is still slightly warm and still moist. Some lichens are fruiting now and mosses will green-up when the next rain falls. If 2) you like paintings of bush flowers visit the artists’ exhibition at the ANBG. Most of the excellent works are by everyday enthusiasts rather than professionals…all are inspiring. If 3) you enjoy reading about the bush and its wildlife seek out A Bush Capital Year by Ian Fraser with Peter Marsack’s evocative paintings illustrating each season’s subjects. If 4) you need a closer-look-picture-book to share with young children try Julia Cooke’s My Little World which focuses on plants and animals found on Black Mountain
* Canberra
Putting Birds in Backyards into Google is another way to research birds from our region.
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