New Zealand

The Black-billed Gull: When the world’s most endangered gull comes to town

19:07 pm on 16 April 2021

By Sally Blundell for Frank Film

Christchurch's population of endangered tarāpuka/black-billed gulls may have a new home.

Christchurch City Council is hoping to fashion a new site for the gulls in what was once part of Bexley, now in the city's red zone.

Christchurch City Council ecologist Andrew Crossland told Frank Film the existing bank would be reshaped to allow shallow flooding of tidal waters during spring tides, leaving small "islands" to mimic the stony banks and islands of Canterbury's braided river systems where the gulls naturally live.

The flock of tarāpuka/black-billed gulls, the most endangered gull in the world, first set up camp in the mangled ruins of an earthquake-munted building in central Ōtautahi Christchurch in 2019. The inner city location currently comprises narrow concrete beams and gravelly pillar tops. While safer from introduced mammals, the site - currently shared with a colony of red-billed gulls, also threatened - is not ideal. Chicks are at risk of toppling into flooded foundations; local business owners have to deal with guano-streaked shop frontages; and work is expected to begin this year on the construction of the new cathedral precinct development earmarked for this block of land facing Armagh St.

A part of their Changing South short film series, Frank Film went location-hunting for a new home for Christchurch's more unexpected arrivals, tracking the efforts of those trying to stop the endangered black-billed gulls from returning to the CBD for the next nesting season.

Andrew Hamlin has been feeding the birds to woo them away from their current location to a more amenable environment. As he says, given the circumstances, "I made the decision to do something, rather than nothing." Department of Conservation science advisor Kerry Weston is not impressed - she is expecting the gulls to return later this year to a more natural environment, where they will have to survive without food handouts.

The Catholic diocese has pumped out the water-logged basement to try and stop chicks drowning in the flooded foundations and is hopeful the onset of construction work will prevent their return. The site will be cleared, says property manager for the new Catholic Cathedral Precinct Tony Sewell, and workers will move in. "It'll be a hive of activity - the gulls don't like hives of activity."

But they do like Christchurch. Records show that 120-130 years ago black-billed gulls were roosting in the salt marshes of Canterbury. In the 1990s, a restoration project at the Charlesworth Reserve in Ferrymead succeeded in attracting a new population of black-billed gulls but a scare of some sort pushed them outwards to the treacherously fast motorway where a number of gulls were killed. The following year, says Crossland, they moved into the CBD.

Now, he is hoping work on the old bank in the red zone will prove a more attractive address for the colony of threatened gulls. The neighbours seem to think so. Already, says Crossland, the surrounding wetlands are home to a huge number of wading bird species.

"People in Christchurch don't really understand this is the central nodal point for wetland bird life in the South Island. There is more wildlife here than anywhere else in the hinterland. There are more than 249 species of bird recorded in Christchurch, more than any other part of New Zealand."