Playing the conservation game

Recent PhD graduate Dr Ox Lennon is using computer game technology to help protect New Zealand skinks.

Ox in a high viz holds two skinks in the field

“My PhD research investigated mitigation translocations for skinks,” Dr Lennon says. “Mitigation translocations are when protected animals are at risk from human development and they need to be moved to a new location to try and mitigate damage to them.

“Some people have questioned the effectiveness of these translocations as a conservation tool—animals might not get squashed by a bulldozer, but they might still die without reproducing at their new location—so I wanted to investigate how effective they actually are and whether we can improve them.”

Dr Lennon’s study was made up of two parts: researching past mitigation translocations of skinks in Auckland sites, and conducting research in Transmission Gully, a new motorway being built just north of Wellington where current developments are posing conservation challenges. This is where the computer game technology came in.

“One of the techniques used in translocations of skinks is building piles of rocks to release the skinks into—the skinks can bask in the sun on the surface and go into spaces between the rocks to hide from predators,” Dr Lennon says. “However, mammals like rats, cats, and mice are still a threat, and mice can often get inside the rock piles and attack the skinks.”

Dr Lennon wanted to figure out if there was a way to choose rocks for the piles so that the holes between rocks were just the right size to let skinks through but were too small for mice to get through.

“In order to do this, I had to figure out a way to see what the holes look like inside the rock piles,” Dr Lennon says. “Unfortunately, you can’t really do that with physical measuring techniques—the holes are too winding and labyrinthine to put anything like a ruler or a probe inside, and if you try to take a mould you can’t remove the rocks, so you just end up with a pudding of rocks and no way to examine your mould!”

Dr Lennon decided to take a virtual approach, using a computer games programme that has in-built physics software to model virtual rock piles that they could look inside.

“These physics programmes are designed to make computer games look realistic, so if you knock over a pile of boxes in the game, for example, they fall like boxes would in the real world,” Dr Lennon says. “I was able to make different realistic rock piles using this software to see what the holes were like inside and hypothesise a design that would protect skinks from mice.”

Dr Lennon then made real rock piles based on these models and tested them at Transmission Gully.

“Unfortunate there weren’t many lizards released in the end, so I didn’t get enough data to say whether or not my rock piles worked, but this is something that could be tested further in the future,” Dr Lennon says.

Despite this, Dr Lennon’s study still provided further insight into the success of mitigation translocations for conservation.

“The work I did showed that while mitigation translocations were usually fulfilling their legal requirements, they weren’t generally resulting in conservation benefit,” Dr Lennon says. “This supports what people in the field have long suspected about the effectiveness of this technique.

“These translocations are being implemented all over the country, so I hope practitioners and law-makers will use the evidence I’ve found to rethink how they’re used.”

Dr Lennon’s research suggests that the legal and regulatory structures underpinning mitigation translocations should be improved, that these translocations should be implemented to the same standard as conservation translocations, that mitigation translocations should be used in conjunction with other strategies, and that the techniques used for mitigation translocations (like rock-piles) could be improved.

The research is timely as it could have bearing on the reform of the Resource Management Act, one of the pieces of legislation underpinning the use of mitigation translocations in New Zealand.

“New Zealand is also creating a new nationwide biodiversity strategy which I think could benefit from this research,” Dr Lennon says.

These translocations are also used internationally, which could make this study of interest across the world as there has been very little previous research into the long-term effectiveness of these translocations.

“I’d also like to say that my rock piles could be useful for backyard conservation, although I don’t have the statistical evidence to back that up! Hopefully I can be more definitive after they’ve been tested further,” Dr Lennon says.

Dr Lennon hopes to continue working on conservation science after graduation.

“I wanted to do my PhD on a conservation topic because conservation is something that I think is really important and is an issue that really moves me. My supervisor Nicky was looking for a research student to get involved in the Transmission Gully Project, so this project was the perfect fit.”