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We love our snakes. Image: Toby Morris
We love our snakes. Image: Toby Morris

ScienceDecember 20, 2022

The banded sea krait is New Zealand’s sea snake

We love our snakes. Image: Toby Morris
We love our snakes. Image: Toby Morris

We have snakes in New Zealand, and it’s time we embraced that fact.

Clinton Duffy, a Department of Conservation (DOC) veteran, is New Zealand’s default sea snake expert. He adds the default bit when I ask him how he became the “go-to sea snake guy”, explaining that over the years, as it’s become apparent that marine reptiles actually do swim in our waters, he picked up sea snakes as part of his beat. He’s also a shark guy and a sea turtle guy.

I called Duffy under the guise of trying to prove a ridiculous and fantastical theory that I haven’t stopped thinking about all weekend. A banded sea krait was spotted swimming in Auckland’s Viaduct harbour a month ago. Last Tuesday, one turned up on Auckland’s Takapuna beach. The idea that these two sightings could be of the same snake has been as alluring to me as the promise the serpent made to Eve about becoming god-like upon eating forbidden fruit.

Fed by an unhealthy love of rivalry between Wellington and Auckland, I wondered if proving that it was the same snake would grant Auckland an animal mascot. Could this snake be our Mittens? A more dangerous-sounding and exotic talisman for a more dangerous and exotic city? Should we name the snake as we have done in the past with happy-footed penguins and genetically modified sheep? Is Auckland entering its Reputation era? Is the banded sea krait now New Zealand’s snake? 

I ask Duffy if it could be the same snake and disclose that I have had an obsession with snakes since I was a child so he knows I am a snake sympathiser. I do not ask the Taylor Swift question. To my delight, Duffy can’t rule out that it could be the same snake. The images of the snake in the Viaduct didn’t allow him to gauge the size to be able to compare them, so it’s not an impossibility. There’s also a very good chance that it’s two different snakes. 

Not the banded sea krait spotted in the Auckland’s Viaduct but very beautiful nonetheless (Image: RNZ/AFP)

Unsurprisingly, as a sea snake guy, Duffy is pretty relaxed about the two recent sightings. It’s not new or novel for these snakes to turn up here and they have been doing it for a long time. Sea kraits ride the east Australian current which sweeps down the coast of Australia, swings out to the Tasman Sea, and eventually connects with the east Auckland current. Three species of banded sea krait have made themselves known here but the most common is the yellow-lipped banded sea krait.

Unlike the yellow-bellied sea snake which we also see here, a “truly pelagic snake”, says Duffy, kraits don’t swim deep. They prefer shallower waters around lagoons. They’re amphibious and come ashore to digest food, drink fresh water and lay eggs. They can move on land. If they’re here, it’s a bit of an accident and they’re probably in trouble. It’s highly unlikely a breeding population could be established in New Zealand as it’s just too cold. The snakes might survive a New Zealand summer but would perish in the winter. They are a tropical snake and while marine temperatures are warming and everyone has been complaining about the humidity, New Zealand’s north still maintains a subtropical climate.

Sea snakes might be far from their typical home when they arrive here, but they’re also considered a native species in New Zealand as they arrive here on their own steam. They’re rarely sighted but they’re legally allowed to be here and it’s an offence to kill or harass a sea snake, or possess one or any part of one without a permit. It might be time we stopped pretending they are freaky foreign invaders spawned from Lucifer himself.

Even in the highly unlikely event of them establishing any kind of population in New Zealand, Duffy explains that the banded sea krait is very, very docile and “supremely confident in their toxicity”. Kraits are highly venomous but their confidence in that supremacy is more comforting than it sounds. They are, like Lauren Cooper, just not that “bovvered” by us. They’re not aggressive and their existence doesn’t revolve around human interaction. In Mean Girls speak, we are Janis Ian and they are Regina George.

We are the Janis Ian and the banded sea krait is Regina George.

Duffy has been diving in areas overseas where there are hundreds of these snakes, often much larger than we would see here, and they have a very distinct “leave me alone” vibe. He says they swim around you to get to the surface for air and rightly points out that New Zealanders visit plenty of places where large banded sea krait populations thrive.

Banded sea kraits are also a stunningly beautiful example of evolution. Sea snakes evolved from terrestrial (land) snakes, developing a paddle-shaped tail for swimming, valves to close their nostrils and large lungs to provide oxygen while under water. Their colouration is a deliberate evolutionary style choice, designed to warn predators away. Rather than camouflage to blend in, sea kraits stick out, their stripes a reminder to all to GTFA.

It’s right there in the name, but you could also argue a sea snake is more entitled to exist in our marine environments than we are. Duffy makes the same case for sharks. We take years to learn the skills required to not simply sink to the bottom of the ocean and otherwise conquer the oceans by building craft to float on top of it. We have not developed tails or larger lungs.

I ask Duffy why he thinks we respond quite irrationally to snake sightings, especially in New Zealand, garbling something about mysticism, the bible, New Zealand exceptionalism and their lack of legs. He thinks we do have a reasonably primitive and quite understandable reaction to animals we regard as dangerous but that we are quite enamoured of the idea that New Zealand has no dangerous animals. Sharks and a couple of venomous spiders are as perceptively bad as it gets. Duffy says, quite bluntly and plainly, that while we’ve been told we don’t any  snakes in New Zealand, we do, in fact, have snakes in New Zealand. He also agrees that the way they glide is a disconcerting movement to encounter, as I once again bring up the fact that they have no legs.

Duffy is clear that the arrival of terrestrial snakes in New Zealand would be a different seething mass of problems altogether. Any would be catastrophic to our native wildlife population. I ask him whether he’s heard about the wild stories about a population of copperhead snakes living in the West Coast mines. He has not and tells me the Ministry of Primary Industries would be all over that.

Finally, Duffy wants us to know two things. Firstly, if you think you see a sea snake, it actually could be a snake eel. Snake eels are found in warmer water in northern New Zealand and Duffy says calls to DOC about snakes often turn out to be calls about snake eels.

His number one message however, is applicable to all wildlife (and Britney Spears). Leave them alone and appreciate them for what they are. If you think you see a sea snake, leave it be and don’t touch it. Maybe take a photo so people like Duffy can better observe our serpent brothers from other mothers. Definitely call DOC on 0800 DOC HOT (0800 362 468).

Sea snakes are not land racers. They’re not about to chase you down the beach. A washed up yellow-bellied sea snake is likely to be in a torpid state, essentially hibernating. A banded sea krait moves at one fifth of the speed on land as it does in the water. Even in the water, they would really rather you weren’t there but will avoid you. The most recently recorded death by sea snake bite in Australia is believed to be the first in more than 80 years.

Just as we’ve become accustomed to treating species we generally accept as native to New Zealand with care and respect, the banded sea krait, one of New Zealand’s sea snakes, would very much like to be left alone.

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