Tui To Go "On Air"
Thu, 23 Sep 2004
Tui To Go "On Air"
Tui to go "on air" Tui are set to get airtime in more ways than one, as researchers prepare to radio track birds to find out where they nest, and how successful their nests are. Hamilton has low numbers of tui compared with many cities.
Hamilton Landcare Research staff are conducting research on how many tui visit central Waikato properties, and what plants they feed on. Their overall aim is to design planting and predator control strategies to increase the presence of tui in and around the city. Their work should also help other urban centres to increase tui numbers. Landcare Research scientist John Innes says public response to a request for tui sightings has yielded much valuable information.
Radio tracking will help fill in gaps. "We have reports of sightings around central Waikato spanning three years. From these we learned that during the breeding season from November to February, tui occur only in native forests, or within one kilometre of them. Tui first appear in semi-urban to urban areas from about May, when nesting finishes, and feed readily on introduced plants in parks and gardens over winter and spring; possibly because very few native plants flower in winter.
These results mirror results from an Auckland study in the 1980s, so would seem to represent a clear pattern. "Armed with this information, our next step is to use radio tracking to ascertain exactly where the urban birds go back to nest.
This is a key step to deciding where best to target control of rats, possums and other predators that are reducing tui numbers. "We know from our sightings that tui breeding success is poor as the birds in Hamilton are generally only seen in ones and twos, whereas these foraging trips should be by family groups." Mr Innes and his team have previously caught and banded 11 tui in a time-consuming process of luring them down from trees with recorded tii song.
From today, Mr Innes and colleagues will target more in the same way, attach small radio transmitters, and then release and track the birds. The transmitters will reveal the exact locations of the birds as they move around urban and rural areas and choose their nesting sites. Mr Innes says the transmitters will be attached to the tui's main tail feathers, and will stay on for about five months until the birds moult.
"The first four weeks should tell us what we need to know about where these birds are nesting. Monitoring after that will tell us the fate of the nests." Mr Innes says the knowledge gained through this project will be applicable to many other urban areas as well. For example, tui are rarely seen in Christchurch. "Tui seem to be winter visitors only to urban areas all over New Zealand. If there are reasonably large forest areas in or adjacent to towns, the towns will have tui all year round. However, factors such as predation and lack of food supply are likely to be generally the same everywhere, with small local variations."