Hundreds of dead little blue penguins, also known as kororā, are washing up on beaches around the Far North as the numbers of the cold-water birds plummet.
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RNZ has previously reported more than 40 had been found dead in Tokerau Beach over the space of two weeks, but that is only the beginning.
The Department of Conservation is now warning the kororā aren't the only birds feeling the impacts of climate change in the Far North.
Vaughn Turner created a checklist of birds he spotted while walking the Te Araroa Trail at the end of May, but his documenting of the wildlife soon took a depressing turn.
Turner started noticing dead kororā as he walked from the south end of 90 Mile Beach.
"There were quite a few which seemed odd, so I thought I'd start counting them to see how many there were."
For three days he counted penguins.
"On the first day 75 dead penguins over a distance of 10 kilometres and then day two, walking north, counted them again, that morning I counted 71.
"The third day, I counted about 59 dead birds."
Turner estimated there would have been more than 200 each day over the 30-kilometre walk.
"Some of them are up in the dune toe, or up in the dunes. It was well above the high tide marks, they've probably been there a while.
"A few looked like they've been predated on but many of the birds I found were at or below high tide, so they, I assume were fairly fresh."
Justin Penney also walked parts of 90 Mile Beach at the end of May and collected 109 dead penguins, an albatross, and a few dotterels.
Photo: Supplied
Just last week he found 183 kororā, among other birds like the fluttering shearwater and diving petrels.
Kevin Mathews from Birds New Zealand lives just north of Kaitaia.
He said groups had been doing monthly checks around the area, and they'd also been finding birds washed up in huge numbers.
They throw the birds up towards the dune to prevent them from being re-counted.
"One of the first things I do is look at the condition of the bird, see whether they've died at sea or have struggled to shore and died on the dune line.
"The birds that I found that were freshly washed ashore [so it] certainly appeared that they'd died at sea.
"You can do a little simple test by checking the sharpness of the keel bone on the breastbone, and they were in very poor condition."
Department of Conservation's Graeme Taylor said this huge number of deaths is caused by rising sea temperatures.
During La Niña years, the penguins struggle to find food and end up starving and becoming hypothermic.
Now the warmer years are increasing.
"In the past, you might have had a lot of good years followed by one bad year where a lot of birds die, but then they rebound in those good years.
"But if we start to see the balance tipping towards more bad years versus good years, then they're just not going to be able to recover."
Taylor said it was not just kororā that were facing extinction in the Far North.
"We've lost whole colonies of the tītī or muttonbird or sooty shearwater.
"In the Far North, there used to be quite reasonable colonies up there, but most of those colonies have now gone, and we've only got a tiny handful of them still breeding in the north.
"They were going down a little bit, but then they really plunged from about 2010 downwards.
"Since then, we've been starting to see the entire colonies disappearing."
The kororā have the same problem, and it was getting worse, he said.
"I've just had reports sent to me that this isn't just actually involving chicks, there are now adults dying as well, which is even worse because if adults die, you know then they're not back to breed the following season to replenish the population.
"So those are sort of quite alarming things to find."
Taylor expected the area would lose cold water birds but gain others from the tropics.
"We're already starting to see some evidence of species that breed up around the Kermadec Islands, for example, coming down to the Hauraki Gulf and around the Three Kings.
"Tropical boobies species turning up, roosting at Muriwai and noddies and other species that just didn't used to come down the far south."
While that's not necessarily a good thing, it's proof of the drastic way the climate is changing the world and its wildlife.