Snakes on a drain – ‘snake free’ NZ found to have Aussie serpents

New Zealand’s centuries old reputation as a country with no snakes is at an end, after the owner of a gold prospecting company confirmed he’d encountered snakes on the rugged West Coast of the South Island.

Bob Radley, now retired, was prospecting in the Grey Valley with his geologist son in 1990 when they were clearing scrub from the tailings and sluice of an old gold mine.

Radley told Radio Live’s Ian Wishart and Mark Staufer on”The Truth” show last night that he felt something on his arm and looked down to see a green and brownish snake coiling and writhing around his wrist.

“Such was my fright I immediately flung my arm out and sent the reptile flying down from the height of the sluice face to rocks at its base,” Radley said.

Stunned, the two men asked other colleagues in the West Coast gold mining industry and discovered “three others” had encountered the snakes.

“We reported our discovery to MAF,” Radley told the show, “but they didn’t seem too interested”. While later doing some scientific work for the Crown Enterprise Landcare, which specialises in flora and fauna, Radley said he broached the subject with one of their senior scientists who confirmed they were aware of  reports of a small colony of snakes in the West Coast gold mining districts.

Radley identified his snake from photos as a Victorian Copperhead, a type capable of growing more than a metre in length and deadly, although the snake was shy and not generally aggressive, resulting in few interactions with humans even in its native Australia.

It’s believed the snakes arrived during the gold rush of the 1860s and 70s, when thousands of miners emigrated from the Victorian goldfields to the West Coast, bringing their mining equipment with them on the many sailing ships that berthed at Hokitika and Westport. In those days there were no biosecurity checks, and any snakes that had stowed away in miners’ crates would get a free ride all the way up to the goldfields deep in the hinterland.

Radley, who holds a Ph.D, rejected any suggestion that the creature may have been an eel: “it was 150 feet above the stream level”, and he added he’d previously encountered snakes on his work in Australia and North America. “It was a snake,” he confirmed on the radio.

Biosecurity NZ, a division of the Ministry for Primary Industries which took over responsibility for exotic fauna from the old MAF, told Radio Live’s “The Truth” it had no record of snakes naturalised in New Zealand, but was now investigating:

“MPI is not aware of a colony of Victorian copperhead snakes anywhere in New Zealand. An initial search of databases has not found any record of a notification of these snakes being made to the Ministry through its exotic pest and disease hotline.”

The department added that it recommended anyone who “has seen these snakes makes a call to MPI’s free hotline on 0800 80 99 66 so that we can investigate this further.”

Biosecurity NZ said it would “make contact” with Bob Radley to discuss his sighting and that the file “is being passed to our investigators”.

Meanwhile, the Ministry of Health confirmed  it holds no antivenom capable of treating the bite of a Victorian copperhead. The only snake antivenom in New Zealand is held at Auckland Hospital and it is CSL Polyvalent Snake Antivenom, which is effective against sea snake bites. Manufacturer CSL says its “CSL Tiger Snake Antivenom” is the recommended product for copperhead bites. New Zealand has none.

The bad news is that after 150 years the cost of locating every snake on New Zealand’s West Coast would run to millions of dollars and man-hours, and even then would be unlikely to find them all. The good news is that there is no record of anyone being bitten by a copperhead in the 150 years they’ve been here, and they clearly have not bred to the point where the South Island is overrun with snakes.

An Australian snake website describes the Victorian copperhead as growing up to 1.8 metres (six foot) in length, “are highly venomous poisonous snakes native to the temperate territories of southern and eastern Australia. Well adapted to cooler climates, they are the only Australian snake found above the snowline. These snakes prefer fertile wetland and swamp habitat and are known to congregate in large numbers when conditions are optimal. Excellent swimmers, Australian Copperheads are very much at home in river, swamp and marshland habitats. They tend to gather where prey is plentiful and a major part of their diet is frogs and tadpoles. As generalized carnivorous hunters and they will eat any suitable sized prey – including one another and even their own young!”

On the West Coast, their diet is expected to include possums and rats.

A search of old newspaper archives confirms snakes have been found in the wild in New Zealand in the past:

“The following is from the Bay of Plenty Times: Captain Bluett, A.C., inform us that some of his men were sawing timber at Oruatewehi, a place about two miles from Fort Galatea, they discoyered a snake, between three and four feet in length, holding on to a weta (native spider). The natives, who have an intense hatred and dread of snakes, unfortunately chopped it up there and then into mince-meat. Fortunately, Sergeant Hall, of the A.C., who was in charge of the sawing party, saw the snake before its destruction, so that there cm be no doubt as to the authenticity of the statement. We understand that this description of snake is occasionally to be met with up north, but believe it is the first seen in the Bay of Plenty.” We are inclined to think Captain Bluett and his men have been deceived. This is not the first time that the reported finding of a snake has created a lively discussion, but we never before heard that any description of snake was occasionally to be met with up North.” – Thames Star, 5 April 1875

A constrictor was caught in Auckland at Ellerslie.

Another report from 1892 records the capture of a two metre long “death adder” in Horowhenua – the snake was caught sucking milk from a cow. The Marlborough Express newspaper says it was the third snake caught in New Zealand “in recent years”, and that in this case the farmer had recently emigrated from Victoria, Australia and assumed the serpent had hitched a ride in his belongings.

A two and a half foot long yellow and black snake was caught on a farm near Gisborne in 1889.

The earliest reported sighting of a snake in the wild in New Zealand comes from Pelichet Bay, North Dunedin, in 1862:

“A gentleman informed us yesterday that while walking on the banks of Pelichet Bay, he distinctly saw a snake gliding amongst the scrub. He described the snake as being about 18 inches to two feet long, and stated that on attempting its capture, it darted swiftly across the road into the bush. There are no reptiles of this species indigenous to New Zealand, but it is just possible that small snakes may have found their way in some of the vessels from Australia. If our in formant was correct in his opinion of the reptile, it is to be hoped that it will be destroyed, as the naturalization of two or three snakes in New Zealand, would soon lead to a large number of these unwelcome visitants, the dense underwood of this colony affording so much protection and concealment.” – Otago Daily Times, 14 June 1862

In 1892 two snakes were found to have escaped from two separate ships. One had come from Argentina to Timaru and an infant snake, only six inches long, was found writhing in the sand ballast discharged on the beach by the ship. What happened to its parent or siblings on the long voyage from South America around Cape Horn is not known. Then a couple of weeks later, another infant snake was found on the beach at Oamaru, again from sand ballast, this time from a ship that had arrived from Queensland. The practice of ballast dumping on beaches had been common, and it was only the sharp eyes of witnesses in these two cases that spotted the intruders.

It wasn’t the first live snake that made landfall through ballast at Oamaru.

In 1894 residents of Queenstown were alerted after a snake was seen in the town:

“A slight sensation was created yesterday through the report, which was correct, that a snake had got loose in Queenstown. It appears that, on Wednesday morning last, while Mr George Reid of Messrs Reids’ Brewery establishment, was in the aerated water factory he saw what he asserts was a snake run out of the doorway. The reptile was about a foot long and of a dark brown or black colour, but it glided out so quickly that he had not time to observe it carefully. A long search was made immediately afterwards by four or five hands but no trace could be found of the creature. The only way Mr Reid can account for the undesirable importation is that it must have come in the straw of a crate of bottles from Victoria. It is some consolation that, if Madame Heller’s disclosure last night was correct, there is no prospect of an increase from his snakeship; and it is to be hoped that, unless despatched earlier, our next winter will give him the final despatch.”