Rare alpine gecko in Nelson Lakes remains mystery despite searches

Friday, 2 August 2019

The Cupola gecko, sighted by Roger Waddell in 2007 while hiking in the Sabine Valley in the Nelson Lakes National Park.

A mysterious alpine gecko, seen only three times in more than 50 years, remains elusive despite extensive search efforts.

An elegantly patterned grey and black gecko was first seen in 1968, in scrub above the Cupola Hut in the Travers Range of the Nelson Lakes National Park.

Named after the area it was first discovered in, the Cupola gecko has a grey body with dark markings. It differs from similar gecko species as it has a triangular shaped head with bold V-shaped markings and a shorter snout.

It wasn't until nearly 40 years after that first sighting that Nelson teacher Roger Waddell and his son came across a unique looking gecko while tramping.

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The pair were hiking through the park, having left behind the clear freshwater of the Blue Lake, when they came across a gecko basking in the sun on the side of a scree slope in a river flat in the Sabine Valley in January 2007.

The Travers Saddle, the possible habitat of the Cupola gecko in the Nelson Lakes National Park

'There just on the side of the track was this gecko, which at the time I didn't realise was as rare as it is.'

Waddell was able to take a few photos that he emailed to DOC and reptile experts after the trip. He then received a 'flurry of interest' from those puzzled as to what it could be.

His photos of that gecko appear on posters in DOC huts throughout the Nelson Lakes, 'Have you seen this gecko?' they ask, encouraging trampers to report any sightings of geckos and skinks in a bid to better understand their distribution and ecology.

A decade later after Waddell's sighting, Australian tramper Matthew Shields reported in a hut visitor book that he had seen a 'grey gecko' below the Travers Saddle in March 2017.

DOC contacted Shields, who described the gecko which he had seen basking on a rock on the side of the track, as having a pattern 'similar to lichen'.

There have been several other unconfirmed gecko sightings in the park in the last 15 years and three dedicated searches that failed to locate any geckos themselves.

The Cupola gecko was first seen in 1968, and has since been seen twice by trampers in the Nelson Lakes National Park but little else is known about it's distribution or ecology.

It was Shields' most recent encounter that led ecologists Dylan van Winkel and Ben Barr to undertake a survey in the Nelson Lakes in March, starting with a search of the site where the gecko was last seen.

The pair gained funding for a survey and spent almost 100 hours searching at three sites around the Travers Range but found no evidence of the Cupola gecko, other than a possible scat in a rock crevice near Hopeless Creek.

'One of of the biggest mysteries is that we have got these verified reports of geckos from the Nelson Lakes area but we don't know what it is.

'It was frustrating, but there is so much habitat up there, a lot of it is unsearchable because it is deep rock scree.'

Classed as data deficient, van Winkel said verifying the gecko's existence was a high priority as it could then be given a threat classification, which meant it would be eligible for conservation funding.

'There have been hundreds of hours put into looking for this Cupola gecko and no-one has found them, it's safe to say they are at low density and that may be due to a range of things, but primarily pests.

'They are still there, but probably at low numbers and they are probably using big scree piles and deep rock crevices to seek refuge from predators and snow fall which makes them really difficult to find.'

Van Winkel remained optimistic about the existence of the Cupola gecko, given that over a long period there had been several verified sightings.

He said there was still scope to search different areas of the park and planned to do so, as funding allowed.

'I think you would need multiple trips before you could be confident they are not there anymore just because of how vast the area is.'

DOC science advisor Jo Monks said quite a lot of work had been put in by dedicated people over the years searching for the lizard.

'It is regarded as its own species but we are very keen to get some evidence to look at it genetically.

'None of the targeted searches have picked up another gecko so it remains a bit of a mystery.'

Despite the small number of sightings over an extended period of time, the appeal of the elusive Cupola gecko remains. Waddell spent a night at Cupola Hut in January this year, keeping his eyes peeled in the hope of another chance encounter with the elusive lizard.

'It's almost the herpetological equivalent of the South Island kokako I suppose, that's probably exaggerating a bit, but being so rare it makes it quite exciting.'

It is not the first time in recent history a new species of lizard has been found. In 2014, the Awakopaka skink, was discovered near the Homer Tunnel in Fiordland National Park.

Lizard scientist Tony Jewell✓ discovered the unique skink while photographing weta near the tunnel. There had since been a search with several other scientists but they only managed to find a skink that had died.