Until a couple of months ago, the nocturnal bird known as the nankeen night-heron had been regularly seen at Lake Wendouree. Now it has gone.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
When the small group departed in spring, night-herons had been constantly present at the lake for around two years. Sightings prior to that were irregular, mostly in summer and autumn.
Most of the lake birds were in adult plumage when they left - orange-brown on the back, with a black cap. This plumage takes two or three years to attain, so we assumed that they departed to breed somewhere along the Murray Valley.
Confirmation of this has now been received, with a report last month of a large colony of 1600 night-heron nests in the Barmah Forest, upstream of Echuca.
The nankeen night-heron builds a stick nest in a tree. Other waterbirds are nesting in the flooded redgum forests at Barmah too.
No night-herons could be found at Lake Wendouree or anywhere else in the Ballarat region during a local bird count two weeks ago. In recent years, birds in adult plumage have outnumbered those in the mottled dull immature colours, but before about 2000, immature birds were more usual.
Nesting at Lake Wendouree has been reported only once. Most nesting occurs in colonies, as has recently been reported at Barmah.
Our sightings of night-herons have been mostly made in willows, particularly the smaller, bushier, oval-leaved "grey sallow" species. The night-herons roosted in these all day, even in winter when no sheltering leaves were present. True to their name, they leave their roosting spots about 30 minutes after sunset to hunt at night for small fish, yabbies, mudeyes and frogs.
The nankeen night-heron is not the only waterbird to have left Lake Wendouree this year. Another is the freckled duck, which has been present there for at least eight years, probably longer. It is another waterbird that breeds in flooded inland places.
ONION-ORCHIDS
Onion-orchids become prominent at the end of spring and in early summer, after most of the other orchids have finished.
Rather insignificant plants of grassy places, they are mostly about 20cm tall, light green with a single vertical stem carrying 20 or more tiny stalkless flowers "like small green beetles" the same colour as the stem.
There are two common local species - the common onion-orchid and the slender onion-orchid. They are similar to each other and are not easy to distinguish.
Their onion name comes from their single onion-like leaf. Onion-orchids seem to seed readily, in some places appearing on nature strips and on ovals.
NATURE QUERIES ANSWERED
This little creature was clinging to my wire door. I'm guessing it's a moth but it's one I've never seen before. It's 4.5cm from top to bottom. L.H., Mt Pleasant.
This beautifully-marked creature is a male Common Splendid Ghost Moth (Aenetus ligniveren). Although found all over south-eastern Australia, it does not appear to be common here. Early summer is its usual time.
It was probably attracted to light the previous night.
The wings seem to wrap around below the body. The hindwings, not visible here, are glossy grey. The antennae are surprisingly small.
The female is larger, blotchy green and brown, without white marks; she looks like a different species. Her wingspan is around 70mm, whereas the male's is 50mm.
The ghost moths belong to the same family as the swift moths. They can be identified partly by the way they hold their wings over their bodies.
Questions and photos are welcome. Email to rthomas@vic.australis.com.au, or send to Roger Thomas at The Courier, PO Box 21, Ballarat, 3353.
