Rare mountain gecko remains elusive
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 Nelson Lakes National Park.
Named after the area it was discovered in, the Cupola gecko has a grey body with dark markings. It differs from similar gecko species in having a triangular 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.
The pair were tramping through the park, having left behind the clear fresh water of Blue Lake, when they came across a gecko basking in the sun on the side of a scree slope on a river flat in the Sabine Valley in January 2007.
‘‘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 recalled.
He was able to take a few photos, which he emailed to the Department of Conservation 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 area, with the caption ‘‘Have you seen this gecko?’’, encouraging trampers to report any sightings of geckos and skinks in a bid to better understand their distribution and ecology.
A decade after Waddell’s sighting, Australian tramper Matthew Shields wrote 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 of the reptiles.
It was Shields’ most recent encounter that led ecologists Dylan van Winkel and Ben Barr to undertake a survey in the Nelson Lakes area in March, starting with a search of the site where the gecko was last seen.
The pair gained funding for the survey, and spent almost 100 hours searching at three sites around the Travers Range, but found no evidence of the Cupola gecko, other than possible scat in a rock crevice hear 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,’’ van Winkel said.
‘‘It was frustrating, but there is so much habitat up there. A lot of it is unsearchable because it is deep rock scree.’’
The gecko’s current conservation status is ‘‘data deficient’’. Van Winkel said verifying its 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 snowfall, which makes them really difficult to find.’’
Van Winkel said he 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 he planned to do so as funding allowed.
‘‘I think you would need multiple trips before you could be confident they are not there any more, just because of how vast the area is.’’
DOC science adviser Jo Monks said quite a lot of work had been put in by dedicated people over the years searching for the gecko.
‘‘It is regarded as its own species, but we are very keen to get some evidence to look at it genetically,’’ she said.
‘‘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 that 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.