The protected native species that once prompted the Waitaki District Council to issue a statement saying ‘‘Gulls, gulls, go away!’’ appear to have left the North Otago seaside town in large numbers.
But Dr Chris Lalas, who at the weekend began his annual survey of red-billed gulls with an aerial survey with North Otago Aero Club pilot Sven Thelning, said the birds appeared plentiful nearby.
Roughly 22km northeast of the town a large colony with an estimated 936 nests occupied the Waitaki River mouth.
‘‘This year there weren’t many at Oamaru, but it’s easily been accounted for by numbers at Waitaki,’’ Dr Lalas said.
‘‘So if you’re looking for somewhere for them to have gone, they’ve either gone to Waitaki, or perhaps even Katiki, because they’re the two big colonies.’’
With gulls and many other species observers could never get an exact number for nests, or breeding pairs, ‘‘because quite often if they [nests] fail they renest’’.
He tried to do a ‘‘a snapshot that involved a lot of estimating’’ — and this year birds were in all stages of the breeding season, some birds not having produced eggs yet and others whose chicks had already left the nest.
At Katiki Point, another large colony existed where last year there were an estimated 1190 nests, but the number of birds at the Waitaki River had appeared to increase.
Last year, Dr Lalas estimated there were 721 nests near the Waitaki River bridge, while this year that site was unused.
After hundreds of gulls nested atop Countdown Oamaru last year and for several years before, the company installed a suite of deterrents to prevent the birds from nesting on its building again.
Nearby businesses this year also took steps to prevent the birds from nesting on their buildings after the council used a drone to survey potential nesting sites.
Once nests were formed, they could not be removed as the birds were protected under the Wildlife Act.
At the end of winter, the council also cleared boxthorn from a roughly 100sq m area in a remote corner of Cape Wanbrow, some distance from its well-used walking tracks, in an attempt to provide a more natural habitat for the birds before the breeding season began.
Doc’s conservation status of New Zealand birds (2016) shows the protected species could face a decline in numbers of up to 70%.
