The general conclusion for this behaviour is that it is done for thermoregulation - warming in the winter and cooling in the summer.

The expanse of webbing is capable of absorbing warmth from the sun.

The accompanying photo shows clearly the blood circulation within the webbing.

In summer, it has been suggested that the birds lift their wet feet out of the water to take advantage of the cooling effect of drying.

People are often concerned about this behaviour, assuming that the leg might be injured.

Sometimes the leg is held out at a rather unexpected and uncomfortable-looking angle, but the bird is suffering no discomfort and the behaviour is recognised as normal for all species of swans across the world.

Some swans have been known to have the leg and foot thus exposed for 30 minutes or more, but the period is mostly shorter than that.

Swans are quite capable of swimming with just one foot for short periods, although the "foot out" behaviour is seen more often on swans that are not moving directly from place to place.

It occurs on swans that are resting on-shore, and young downy cygnets have been observed doing it too.

If the foot is not spread, it is most likely a simple matter of resting that foot.

A number of swans have leeches clinging to their feet.

Perhaps - in summer at least - a leech-carrying or otherwise sore foot might be held up in the warm sun in an attempt to get the sucking leech to drop off, or to deal with whatever other discomfort may be present.

There is a small leech at the bottom of the foot in the photo.

The "foot-out" behaviour appears to be a topic for further observation in both summer and winter - especially regarding the angle of the foot to the sun.

Oddly, ducks do not share this behaviour.

The black-shouldered kite is a small white, seagull sized hawk.

Its occurrence here is rather erratic - sometimes it is common, while at other times it is absent.

Its absences may be for months or sometimes a year or more.

This attractive small hawk has increased in numbers this month, after being scarce for several months.

The same can be said for a quite different bird - the white-necked heron. It has been almost absent for a few months, but has now returned recently in moderate numbers.

What is eating the peel on our lemons? A couple are completely missing their peel and three or four are missing about half their peel, and others have scratch marks.

D.D., Ballarat.

Your photo shows the lemons completely without peel, still hanging by their stems. One of the possums - brush-tailed or ring-tailed - is the most likely culprit.

I was pleased to receive your later email with a night-time photo of a ring-tailed possum in the lemon tree. For some reason, the possum prefers the peel, rather than the juicy flesh. The smaller ring-tailed possum is more agile than the larger brush-tail, but nevertheless must be a very skilled operator to be able to remove the peel, while leaving the remainder of the fruit intact and hanging. Rats are also known to eat lemon peel.

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