Traps protect endangered gulls in Kaikōura

A community effort is helping to protect the endangered black-billed gull / tarāpuka.

Environment Canterbury senior biodiversity officer Heath Melville has been working alongside Te Whenua Land Information New Zealand and the Department of Conservation on a trapping programme designed to support the gulls.

The Kaikōura Community Shed has supported the work by building 30 predator traps.

Melville said the gulls were vulnerable to flooding, human disturbance and predators, such as rats, weasels, ferrets, stoats and hedgehogs.

Harrier hawks and southern black-backed gulls / karoro were also a threat.

‘‘We assumed the full range of mammalian predators would be there – feral cats, ferrets, stoats, weasels, rats and hedgehogs,’’ Melville said.

‘‘Sure enough, the 46 traps we laid caught some of everything.

‘‘Even when we dialled back trap checks to monthly, after the tarāpuka had left the site, we were still catching the full suite of predators, even when the bait was three to four weeks old.’’

The Charwell River was one of four known nesting sites for tarāpuka in the Kaikōura and Hurunui-Waiau Uwha zones, Melville said.

He said the Waiau Toa Clarence River hāpua colony continued to struggle, but the Hurunui colony had experienced some breeding success this year.

‘‘The Charwell looks to have had the most success in fledging tarāpuka in the north of the region.’’

A high count of chicks to adults suggested the Charwell River site offered a safer breeding ground compared to other monitored sites.

‘‘Karoro predation has led to the complete failure of tarāpuka colonies at other Canterbury sites so it is great we’ve been able to work with other agencies and a very helpful landowner to give the tarāpuka a better chance at breeding successfully,’’ Melville said.