First a pair, but more recently one, of these rare birds has been seen lately at Lake Wendouree.

The first sighting was in the middle of August, when a pair were seen flying to the west over Fairyland.

The next report was of two birds sunning themselves and preening on the mud islands in the centre of the lake. That was a month later, on September 14.

Since then, all reports have been of just one goose. It feeds (grazes) out on the point at the end of the rowing course, and with swans and other waterbirds on the grass at the end of Carlton Street.

This bird has created a lot of interest from people near and far.

Cape Barren geese are sometimes kept in captivity. The current lone bird behaves as though it is accustomed to people, so it is likely to have been raised in captivity.

Serendip Sanctuary near Lara has had a population of these birds for many years. Many are free to roam wherever they like. The same applies to a farm property at Clunes, where at least one brood is hatched each year.

Enquiries at Ballarat's Wildlife Park, and from residents nearby, indicate that the birds are unlikely to have originated from that property. A Clunes origin seems most likely.

The two recent Lake Wendouree birds may be younger ones from previous years, now driven away by their nesting parents, and - perhaps instinctively - heading south to the coast.

Wild Cape Barren geese in Victoria are mostly coastal birds, although they visit some of the Corangamite lakes in most years when conditions are wetter.

Wild geese are likely to be more timid and alert than the current Lake Wendouree bird, and the busy lake is unlikely to be chosen by them as a stopover.

Thanks to those who have recently sent reports and photographs of the Cape Barren geese.

The first report of flowers of the yellow weedy daisy known as capeweed was made on a sunny September 20. That was at Cambrian Hill. Already these flowers are opening in many more places.

Eastern banjo-frog and growling grass-frog were both heard nearby on the same day. A few days later, these two frogs were heard in a wetland alongside the Yarrowee River just south of Hill Street in Ballarat.

Butterflies are remaining scarce, possibly because of lack of sunshine.

What is the difference between a lichen and a moss?

M.T., Scotsburn.

These two groups can certainly look very similar. Mosses are generally greener and softer, and they have proper - but often tiny - leaves.

Lichens tend to be firmer and often crustier, and they lack proper leaves, although this is sometimes difficult to discern, because they sometimes appear to be leafy. They are often dull silvery-green, but can be many colours, including yellow and orange.

Technically, lichens are not plants, but a combination of an alga and a fungi.

Mosses generally grow in damper or shadier places, while lichens are often out in the full sun.

Probably the best way to distinguish the two groups is by the presence of leaves on mosses. Lichens might have leafy-looking growths, but they do not have true leaves.

Neither group grows more than a few centimetres tall.