LAST week we farewelled Jeremy at Tarlo River National Park after removing his radio collar.

This week we did the same to Tim, who lives in the bush beside Peter Meadows Road. Tim has been wearing an expensive GPS collar that plotted his position from satellites each few hours and recorded it in the collar. We then had to find him through a signal transmitted from the same collar so we could download the stored information.

Unfortunatel y, the transmitter failed and we lost contact with Tim, thereby losing the expensive collar and the precious data.

But to our great relief Kieran, from our research team, eventually found him after scouring Tim's favourite bushland areas. Tristan will now use the recovered collar to plot Tim's daily and nightly activities on a map and we'll discover much new information on male koala behaviour.

Tim featured in a previous column when he sheltered from hot weather by hiding in caves. Such behaviour may block contact with the satellites and so reduce the collar's ability to record its locality and thus indirectly measure time spent in caves.

A sadder farewell was for Brittany whom we had taken to the Wildlife Health and Conservation Centre at Camden for a check-up after she had been reported acting strangely at Ironside Avenue, St Helens Park. We had first ear-tagged her in Spring Creek in March 2003 when she was still with her mother, Courtney. She would have been a year old then, so would be over seven now. Unfortunately, she was diagnosed with advanced leukaemia and had to be put down.

Leukaemia is one of the illnesses associated with a strange retrovirus found in koalas. Tristan has shown that Campbelltown koalas carry the viral DNA but so far we've seen no sign of its effects. In fact, our koalas, particularly the females, have been remarkably healthy and long-lived. It's too early yet to attribute Brittany's illness with the virus. Much money and research is needed to investigate this phenomenon.

Blake Draper and his five helpers, with the assistance of Mac the Koala in the Advertiser, did their bit last week to support the conservation of koalas by raising $346 at the Mary Immaculate Primary School fete at Eagle Vale. Congratulations to them. It's great to see their concern converted into action.

Please report koala sightings on the UWS pager: 99629996.