It was the chrysalis (pupal) stages of this particular colony that were discovered first. The strange-looking black objects had survived the winter. To the delight of the observer, inspection a month later - in mid-October - revealed that many colourful butterflies had emerged.

The imperial jezebel is mostly white with black edges when its wings are fully opened, but underneath it has bright red and yellow spots on a smudgy black background.

A colony like this - which numbered more than 20 butterflies at one stage - is a memorable sight. A dozen more were seen a couple of days later.

MORE NATURE NOTES: Black cockatoos seen moving around area

Like its more common relative the spotted jezebel, the imperial jezebel lays its eggs on mistletoe leaves. Overwintering pupae are black. The pupae appeared to be lifeless when discovered at the end of September, but many butterflies emerged two or three weeks later, after pupating on a sheet of silken web.

Because of its damp conditions and lack of sun, this season has not been a good one for butterflies, with most species being low in numbers so far.

Painted ladies are appearing whenever conditions suit, but yellow admirals are scarce. Common grass blues have been reported in gardens and on nature strips once again. No doubt more species and more individuals will appear when we get a week of sunny weather.

The imperial hairstreak - a Christmas - New Year butterfly - is another colonial species, with pupae and adults often to be found at the same time on their favourite wattle trees.

A guided bird walk at Lake Wendouree and the North Gardens Wetlands a fortnight ago found 44 species of birds. Among these were scarcer birds such as pied cormorant, greenfinch and peregrine falcon. A flock of 60 cattle egrets was a surprise.

Australasian darter, sacred kingfisher and goldfinch were other notable species found during the walk.

Out in the centre of the lake are a lone wood sandpiper, and both magpie geese and Cape Barren geese with their goslings. Other sightings at the lake in October were black-tailed native-hen, royal spoonbill and red-kneed dotterel.

Up to 16 greenfinches have recently been seen there, along with a few goldfinches. They are feeding on elm seeds. A newly-arrived migratory satin flycatcher rested for a few days on the shoreline, on its way to native forest habitat elsewhere.

Away from the lake, blue-faced honeyeaters have recently been reported in gardens at both Canadian and Creswick.

What is this blue slimy creature that looks like a worm? It was in the Lerderderg forest area on October 22. D.M., Bacchus Marsh.

This is a blue flatworm or blue planarian, a worm-like creature that is usually seen only when conditions are damp, such as after rain.

Adults measure approximately 60 mm long. This ground-dwelling creature is native to Australia, but has been accidentally introduced to other parts of the world. Although superficially rather leech-like, it is harmless to humans, feeding on small ground creatures such as slaters, millipedes and worms when the ground is damp. In dry weather it shelters in damp places under rocks and logs.

Its head end is slightly more pointed than its tail, with the head often having a red or orange tinge. Many specimens are duller and darker than the colourful one in this photo.

Email questions to rthomas@vic.australis.com.au, or send to Roger Thomas at The Courier, PO Box 21, Ballarat, 3353.

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