In today’s economic climate it’s getting harder to achieve all the conservation challenges facing us. DOC’s way forward is in developing relationships with communities and businesses to help achieve our conservation goals. So it’s great when local businesses offer a helping hand.
Here in South Westland the Biodiversity Team got a boost when Local Helicopter operator Michael “Clutch” Glynn of Mountain Helicopters donated over $6000 flying time to threatened species protection. Thanks to Clutch’s generosity we’ve been able to improve our knowledge of a recently discovered population of skinks and unearth some rare land leeches on a coastal rock stack.
Last year DOC Marine expert Don Neale made an unexpected discovery of skinks basking on a small, vegetated rock stack during a survey of islands and stacks along the West Coast Tai Poutini coastline. This was a pretty significant find, as the only other lizards known to live on West Coast islands are the endemic Taumaka skink (Oligosoma taumakae) and gecko (Hoplodactylus “Open Bay Islands gecko”). These are two of the rarest lizard species in New Zealand and they’re only found on Taumaka me Popotai (Open Bay Islands).
The Mountain Helicopters donation gave us a chance to get back this summer with lizard expert Marieke Lettink to find out what species these skinks are. They could be related to the Taumaka skink or the cryptic skink (Oligosoma acrinasum) found on the mainland, or maybe we have found a new species altogether….
Getting out there was a bit hairy, as the stacks are very steep and skinny and we were thankful for the skill and experience of pilot Nathan Healey in depositing and removing us safely.
In a bit of a battle of the sexes Marieke and I, pitted our lizard wrangling skills against the boy’s team, Programme Manager Gareth Hopkins and Ranger Jeff Rawles, on a larger neighbouring rock stack. I have to admit the girls had a head start as we already knew there were skinks on our island.
Mostly we caught the skinks using cage traps baited with tinned pear, but Marieke with her lizarding superhero skills caught a few by hand. We got very excited when the boys radioed to say they’d spotted skinks on their stack too!
Although their home is restricted to 2 very small island stacks the population seems to be doing really well. We saw lots of juvenile skinks as well as the adults, so they’re definitely breeding.
Once a skink was caught we weighed and measured it and took diagnostic photos of scale patterns to get an idea of how this population fits into the skink family tree.
Based on physical appearance these skinks look like they are related to Taumaka skinks. There were some differences though, so we’re waiting for the results from analysis of tail tip DNA samples to see if they are the same species.
Given the thriving skink population and the difficulty of access from the shore it’s likely these islands are predator free. The boys ran rodent tracking tunnels overnight and didn’t detect any mice or rats. This is great news! Vulnerable species like lizards don’t have good prospects on the mainland with mice, rats, stoats, cats etc etc…
There was more excitement to come as we settled down in our precarious camps for the evening. As dusk fell hundreds of fairy prions returned to roost, and as we were probably sitting right on top of their houses they tried to roost in our laps and on our heads! While suffering this feathery onslaught Jeff lifted his pack up to find some leeches underneath.
Most leech species live in fresh or saltwater environments, but some are adapted to life out of the water. Very few land leeches have been discovered in New Zealand and with the single exception of a specimen found under a log in Fiordland they have only been observed on islands (Snares, Solander and Taumaka). The Taumaka leech (Hirudobdella antipodium) is only known to live on Taumaka Island and hasn’t been seen since 1995, despite extensive searches. Weka introduced to the island early last century probably eat the leeches and that’s a worry for the survival of this population.
New Zealand’s land leeches are believed to feed on seabird blood, so it’s not surprising that the boys saw them coming out just as the fairy prions came back to roost. Or that Gareth had a couple crawling over his face after evicting a prion from his bivy bag. New Zealand leeches are a bit of a mystery and it’s exciting to think we might have re-discovered the endangered Taumaka leech.
We don’t tend to have spare money floating around to check out new discoveries, so it’s great that Clutch’s generous donation of helicopter time and Nathan’s awesome flying skills made this out of the ordinary trip possible. When people come together with a common vision of protecting our special species and environments we can achieve fantastic results.
For the record the girls won on skinks caught by 21 skinks to 2!