KEY POINTS:
Tui numbers are thriving despite an unidentified threat which is giving the bird various forms of cancer.
This week's controversy about tui disturbing some Wellingtonians with their early morning calls underlines how well the bird population is doing in most regions, experts say.
But the cancer threat has become a focus for scientists.
The director of the NZ Wildlife Health Centre at Massey University, Dr Brett Gartrell, said early research was showing that tui had higher rates of cancer than other native species.
"We are seeing pancreatic and cancers of the liver and spleen. The affected birds seem not to be from any one area, but spread across the country," Dr Gartrell said.
However, the research was in preliminary stages and it was too early to draw conclusions, Dr Gartrell said. Another mystery disease affecting the tui was causing severe neurological disorders, including seizuring, inability to stand and heads twisting to one side.
"We've seen this in honeyeaters before, but it is generally a nutritional deficiency. But the treatments we use for other species don't work with the tui."
Auckland vet and wildlife specialist Peter Turner, from Lindfield Veterinary Practice, said he had seen the disorder, but autopsies had revealed trauma, probably caused by being hit by a vehicle.
cars, domestic cats, and habitat destruction were the greatest threats to the tui, said Ralph Powlesland, a scientific officer with the Department of Conservation.
Despite this, tui populations were generally healthy throughout New Zealand, except the Canterbury region, where native vegetation had been destroyed to make way for sheep pasture.
"Tui numbers are especially increasing in areas where councils and community groups are putting effort into pest control and planting food sources," Mr Powlesland said.
Consequently, being kept awake by the noisy native should be read as a positive indicator that populations were resurging wherever good predator control and habitat restoration had taken place.
"Tui populations are pretty good in and around the Auckland area," confirmed Matt Maitland, who is open sanctuary co-ordinator with the Auckland Regional Council.
"Tuis are one of the great survivors," he said.
"They are a pretty robust bird and will be the one species to survive when others have disappeared."
Mr Maitland said the response to a story on tuis' very early morning singing was understandable. "People have grown up around them; they are part of the neighbourhood.
"People get quite defensive about them because they are easily identifiable.
"If you are woken up by the tui, you are very fortunate because it means you have wildlife in your backyard."
Indeed, said Dr Gartrell, the tui and the native pigeon are the only two bird species to have survived the urbanisation of our towns.
"The tui is iconic. People recognise it," he said.
DID YOU KNOW?
* The tui is unique to NZ
* It can mimic other sounds, including human speech, telephones ringing, other bird noises and tractors.
* It has two voice boxes, allowing it to make a range of noises - cackles, creaks, groans, bells and wheezing.
* It is known to sip fermented flax nectar and has been observed flying drunk.
