Nectar-seeking rosellas bypass pollination

Birds with shorter bills can't steal the nectar - unless they cheat by nipping or slitting the flowers.

The accompanying photo shows a sprinkling of common heath flowers underneath a flowering heath plant at Ross Creek. A close look reveals damage to the bases of some of the flowers.

This is probably the work of a crimson rosella, seeking the flowers' nectar.

The rosella's short, stubby bill and short stubby tongue would not enable it to reach the sweet-tasting liquid, so it has learnt to nip the whole flower off and then lick the nectar. It's surprising that the rosella did not consume the whole flower. New Holland honeyeaters and red wattlebirds learn something similar when seeking nectar from tubular correa flowers.

Unlike the rosella, they make a slit in the bottom of the flower, rather than nipping the whole flower from the plant.

Although these birds have curved honeyeater-type bills, these bills are not long enough to allow the nectar to be reached legitimately via the flower's opening.

Their "bypassing" feeding means that the flowers are not fertilised - an eastern spinebill probing its 26mm bill inside the long tube gets a dusting of pollen on its forehead as it goes from one flower to another, thus pollinating the flowers it visits. The rosella's nectar-feeding also bypasses pollination.

Last week, we mentioned several wallabies living at Lake Wendouree.

This week it is an echidna at Paul's Wetland, in Wendouree's Dowling Street. The echidna was discovered in that wetland reserve last weekend.

This is a surprising report, with an echidna being totally unexpected in suburban Wendouree.

Traffic would seem likely to prevent its travelling, leaving us wondering if it had in fact arrived there on its own, or whether it had been captured somewhere else and then released later at Paul's Wetland.

The wetland is not a suitable long-term spot for an echidna, because it would not support the numbers or species of ants that an echidna would need for long-term survival. Because of this, the animal will probably soon wander off in search of a better site. Hopefully, it will avoid the traffic on the way.

There may be small populations of echidnas at the cemetery, or at Midlands Golf Course, but the nearest larger echidna population could be at Invermay - on the other side of the busy bypass road, the Midland Highway and the railway line.

What is this yellow, mouldy substance that was covering damp decaying gumleaves and leaf litter? The patch of bright yellow was about 30cm across.

F. T. Clunes.

This is a yellow slime mould, a fast-growing, fungus-like mould that can spread twice its size in 24 hours if conditions are right.

It is single-celled, but when conditions are right, millions of these single-celled organisms unite and spread across the ground, grass, twigs and leaves. Mulched gardens are favoured places.

Although its appearance and spread can be alarming, it is harmless, living on decaying organic matter. It reproduces by spores, which germinate in cool, moist conditions. They soon grow to spread as a mass, before producing their own spores to keep the cycle going.