Feature

Bashful Birds

The royal albatrosses on public view at the Taiaroa Head colony near Dunedin are showing increasing tendencies to shy away from human view, according to a Department of Conservation study. This has led to concerns about how to effectively manage the colony to protect the birds while enabling the site to continue to be a world attraction.

Visitor numbers have risen dramatically, from fewer than 3,000 in 1980 to almost 44,000 last year. They have been drawn by the only site in the world where albatrosses live and breed within easy access of visitors. However, while the visitors have been watching the birds, so the birds have been taking note of them. Around 60% of the birds bred and reared in public view are now choosing to find less public breeding sites of their own.

"There's a quite significant trend for them to disappear off round the corner, " says DoC scientific adviser Christopher Robertson. Those bred directly in front of the visitor observatory are more likely to establish their nests further away. That the shift is related to visitor impact is evident -- those nesting areas where birds can clearly see visitors through the large glass windows are expanding more slowly than those downslope where birds can only catch a glimpse of visitors' heads.

"The nesting evidence clearly shows that a majority of the adolescent albatrosses do not like doing all their courting while on public view," Robertson states. Despite the close monitoring of the site, such a subtle change in the birds' behaviour has taken a considerable amount of time to detect. Analysis of records has shown that each significant increase in permitted viewing time has been reflected by more birds going elsewhere. Fortunately, such shifts do not appear to have affected the colony's overall breeding rate as yet.

While there have been attempts to keep the site as undisturbed as possible, compromises have been made to cater for tourists. What was a major nesting site until the 1950s is now a car park. The major courting area of the 1930s -- prime nesting habitat -- now holds the reception centre. Areas in the reserve nearby have not been used for nesting or courting since visiting began in 1972. Robertson is worried about the potential long-term impact on the colony as more birds choose to nest in other parts of the reserve.

"Not only has visiting affected distribution of nesting, but it has effectively reduced the available undisturbed nesting area in the nature reserve by as much as 50%", he reported to a wildlife protection conference. At some stage, the colony is likely to run out of undisturbed sites and may even end up establishing itself elsewhere.

For the present, some birds are now nesting in unsuitable sites, and there have been adult and chick deaths from heat exhaustion and flystrike because of this. Flystrike has become a problem in the last three years with the arrival on-site of an Australian blowfly. In previous years, DoC has mown strips of land to provide easier movement for birds on the ground. Such access paths also provided clear views of the nests. The blowfly's arrival saw this mowing stopped in an attempt to discourage the introduced pest. However, this means that the nests are not as easy for visitors to spot, leading to some debate over priorities.

There are a number of possible modifications that could be made to reduce visitor impact on the birds. Robertson suggests that providing underground access to the observatory and reducing the visibility of viewers could help. A shuttle bus to the site would reduce the need for parking and lessen movement on-site. The financial costs have to be weighed against the environmental costs on the birds of continued visitor growth, and also possibly the long-term financial and environmental costs of losing the world's only readily accessible albatross breeding colony

Given the increasing popularity of ecotourism in and around New Zealand -- watching whales in Kaikoura, gannets at Cape Kidnappers, penguins in Otago, seals in the sub-Antarctic islands -- these costs are ones that have to be carefully counted.

Vicki Hyde, NZSM