Lake Rotorua community upset over ongoing bird deaths - poisoning suspected

At first, dead birds being found on the Hamurana shores of Lake Rotorua did not ring alarm bells. But then the body count kept growing.

Authorities suspect the birds are being poisoned by someone, but cannot say why, by who, or whether it is a deliberate act or unintended by-kill - and are at a loss.

People in the community are sad and upset by the deaths, which include ducks, black shags, a cygnet and protected red-billed gulls.

Department of Conservation (DoC) compliance officer Hayden Loper said it was aware of 14 birds that died in May. But this number may be higher when combined with locals' finds.

Current evidence pointed toward poisoning.

He said DoC found out about the deaths in mid-May when a duty ranger went to the area and picked up five sick birds that were, at the time, still alive. Another two were already dead.

Birds have been found dead at the northern end of Lake Rotorua for months. Photo / Supplied

He took them to a local vet and, when two more of them died, a necropsy was performed.

Among less alarming contents found, like fish and chips, was something unidentified.

"He suspects it is alphachlorolose, which is a common poison used on birds."

Typically used as a sedative, he said it was a more humane way of killing unwanted species.

Fish & Game staff had also found the substance at Hamurana, where the birds were found.

Samples were uplifted and are being analysed.

On May 18, DoC found six dead red-billed gulls, two dead mallard ducks and two dead black shags.

Loper said he learned from locals the deaths had been happening for the last two months.

"We don't know. We don't know why someone would do this."

The best theory he had was there was a pest bird species that someone was targeting and the rest were by-kill.

"It's really hard to know."

Use of the poison was controlled but it could be purchased from farm stores.

It was an investigation where no answer may ever be found, he said.

"We should figure out the cause of it ... as to who or why, we may never know."

The Department of Conservation has received reports of birds of several species being found dead or dying at Hamurana Reserve. Photo / Supplied

Loper said he had not had to deal with anything like this in the year he had been in the role, and imagined it was quite rare.

He encouraged members of the public to contact DoC if they knew anything.

"We don't have much to go on ... we're at a loss really."

Hamurana Store owner Harjinder Kaur said it had been a big issue in recent weeks and she had found two dead birds.

She said there were times when there was at least one bird post a day on the local Facebook page.

Birds had been found on the walking track, by the park and by the lakefront.

"It's very sad and upsetting. It's not good."

She said the local community was keeping an eye out for anyone doing anything suspicious.

"My community is so good, it's lovely. We look after each other ... we all look after the birds and the animals."

The poison suspected of being used is sold under a number of brand names and forms, and when the paste version is used in public places, warning signs should be installed.

There is a legal obligation under the Agricultural Compounds and Veterinary Medicines Act (administered by the Ministry for Primary Industries) to use any alphachloralose products as specified on the label – this includes only targeting species on the label.

The use of alphachloralose in a public place requires authority from the landowner.

Iwi Ngāti Rangiwewehi, which owns the Hamurana reserve, said no one had been given permission to use the product at the site, and local councils had also confirmed they had no active bird control operations in the area.

Ngāti Rangiwewehi Te Tāhuhu o Tawakeheimoa deputy chairwoman Mercia-Dawn Yates at Lake Rotorua. Photo / Andrew Warner

Ngāti Rangiwewehi Te Tāhuhu o Tawakeheimoa deputy chairwoman Mercia-Dawn Yates said the iwi valued wildlife, including any that made Hamurana its home.

She said everyone had a responsibility to be kaitiaki.

"So if anyone notices any ill or foul play going on around this particular area of Hamurana please notify the agencies and Department of Conservation."

Ka tino pōuri te ngākau, she said. "My heart is saddened to hear that this type of behaviour has taken place, especially around our mana whenua."

Eastern Fish & Game officer Anthony vanDorp said he had been hearing about bird deaths since mid-March.

"Not in massive numbers at one time.

"But it is a mystery as to what's been going on."

Whether the cause was natural or not, he said there was concern.

Each individual death did not ring alarm bells, but he said when looking at the deaths collectively it "paints a picture of something being not quite right".

In his 14 years with Fish & Game he had not heard of anything happening to the same degree.