A photo of the so-called "Canterbury panther".
There have been more reports of big cats in the South Island - this time from RNZ listeners, with four people giving varying accounts of sightings.
Yolanda van Heezik is a professor in the zoology department at Otago University and she says the sightings of these large black cats are completely legitimate, though it is "extremely unlikely" that we have panthers or pumas living in New Zealand.
"We should believe their eyes, what they are talking about is seeing a really large black cat and that is what they are seeing.
"People sometimes have this misconception that feral cats are scrawny but that isn't always the case."
If you apply Ockham's Razor, the likelihood of there being big cats in New Zealand is negligible, she told Jim Mora.
"No one's ever caught one, no one's ever got really good evidence that they are something different from just a large feral cat.
"And there's also a complete lack of evidence that is indirect like if you had a really big cat like that you would expect there to be more stock kills, for example, but we don't really have that evidence either."
The sightings are genuine, Van Heezik says. "I'm not contesting that these are really large individuals, it's just extremely unlikely that they're not large feral cats."
The Department of Conservation has been tracking large swathes of the country for decades and turned up no evidence of big cats here, she says.
Animals can vary hugely in size within a particular species, Van Heezik says. Foxes were a good example, ranging from 2kg to 17kg.
"That's what's happening probably with cats in New Zealand, they are in a place which is may be cooler, so they are following this biological rule called Bergmann's Rule where as you go into the higher latitudes where it's cooler your body size tends to get bigger to save loss of heat because you are reducing your surface area to volume ratio.
"But also in New Zealand they have a large prey base of rabbits, they don't have many competitors for their prey, they don't have any predators themselves.
"You are seeing them reach their biological potential I suppose in terms of their size."
- RNZ
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