Online photos of vehicles driving through a nesting colony of the most threatened gull species in the world has prompted a Department of Conservation investigation.

On Monday, DOC received reports of multiple vehicles, including four-wheel-drives and motorbikes, driving through the Ashley River colonies of the black-billed gull.

The photos were taken by a member of conservation organisation Braided River Aid and posted to Facebook.

“One 4wd was seen to speed up when approaching the birds. Most chicks can fly and get out of the way to some extent, but at least 10 have been killed.”

A Braided River Aid spokesman said he didn’t believe the vehicles responsible were part of any official 4Wd club.

DOC North Canterbury Operations Manager  Kingsley Timpson said “it is unacceptable for people to drive through colonies of this threatened bird.”

“People driving through the area and disturbing the black-billed gull has been an ongoing problem. DOC encourages drivers to take notice of the signage near the colony and give the birds space while they are breeding.”

“He said Black-billed gulls are endemic to New Zealand. They are the most threatened gull species in the world and listed as Nationally Critical.”

“The gulls are an absolutely protected species under the Wildlife Act 1953. Anyone who disturbs black-billed gulls and/or their nests can be convicted with penalties ranging from fines up to $100,000 and/or up to 2 years imprisonment.”

In the South Island, Black-billed gulls typically nest in colonies in the South Island’s braided river systems, on bare gravel islands, that allows some protection from predation and for natural behaviours to be expressed.

These include protection of chicks who huddle when parents are feeding, cooling by using the river’s edge to put their feet in and having a plentiful source of food nearby.  

Several people have been prosecuted for killing gulls in the past, including:

• In 2019, DOC prosecuted a 64-year-old from Blenheim for driving over red-billed gulls, killing at least 8 birds. He was convicted and sentenced to 3 months community detention, and $700 costs.

• In 2019, DOC prosecuted a 26-year-old from Kaikoura of driving over a flock of red-billed gulls, killing at least 3 birds. He was convicted and fined $3000 and costs of $1500.

• In 2015, DOC prosecuted a 33-year-old from Invercargill for shooting black-billed gulls, killing at least 1. He was convicted and fined $950 plus $100 costs.