Has your cat ever brought in a nice present only for you to find it’s a lizard? Have you seen a lizard scutling away on a nice sunny summer’s day while walking around the garden? Well, you may have lizards residing in your back yard!
In New Zealand we have over 125 different lizard species, 76 are skinks and 48 are geckos, all but one one skink species is native. Of these 126 species, 49 (~36%) are Threatened and a further 67 (~50%) are At Risk (Hitchmough et al., 2021). Therefore 86% of our lizard species are threatened by various factors, such as predation, urbanisation, habitat fragmentation, and agricultural intensification.
We all need to play our part to ensure that lizards do not continue to decline.
There are simple tools we can use that can help the lizards in our back yard. Skinks love to hide under rocks and in small gaps when startled. Geckos love to live in tight crevices, like spaces in wood, stone and even in various human-made structures (e.g. power boxes and garages).
We can create structures called Artificial Retreats (ARs) that mimic these natural retreats that lizards love so much. Artificial Retreats are a tool that we can easily implement that can support vulnerable lizards.
Currently, artificial retreats have been designed for scientific monitoring and are commonly constructed from roof-cladding Onduline sheets, which isn’t an easily accessible or cheap material. My thesis investigated two other alternative designs that are constructed in a manner that is easily accessible to landowners and public members keen to do their part in lizard conservation.
One AR type was constructed from a stack of three bricks (Figure 1) that have a 10 mm wooden dowel stuck between each layer so that the lizards can easily move between them.
The second was constructed from two plywood sheets (Figure 2), bolted together, with the 10mm dowel in between the sheets.
The third was the common Onduline design (Figure 3). I tested these ARs across Canterbury farms located at Cleardale Station in the Rakaia Gorge, as well as Flea Bay and Goughs Bay on Banks Peninsula.
I captured 26 lizards to test in the three AR designs and there was no preference among the three. However, the geckos at Cleardale Station preferred some designs more than the Flea Bay lizards. At Flea Bay, the lizards were more commonly found in the brick (46% of all geckos) whereas at Cleardale they didn’t use the brick ARs. At Cleardale Station, a equal number (17%) were found in both Onduline and wooden ARs. At Flea Bay, 17% lizards were captured and only 4% of lizards were found in the Onduline design at Flea Bay.
Depending on the location of the property and the species of lizards present, there will be differences in which AR they prefer. Having an option of several different AR designs is preferable.
During the field trials I found that the ARs did not withstand heavy stock (cattle)interactions and were frequently interfered with. However, I did not have any problems with ARs placed in sheep paddocks.
Landholders can implement any or all three of the designs into their property and all have a chance of lizard occupation. A variety of designs means that landholders can choose which AR design to use based on what available materials they have.
Having a choice of AR designs make it accessible to whomever wants to conserve lizard species on their properties without having to spend large amounts of money or spending valuable time having to source the materials to construct the AR.
Key design components and considerations when planning and building lizard ARs.
- The ARs need to have at least one gap that has a 10mm gap.
- Placed in an area where lizards or their poo have been seen.
- Recommended not to be placed in a paddock in cattle.
Acknowledgements: A massive thank you to the financial support for this project from The Brian Mason Trust and the North Canterbury Forest and Bird Trust.
Reference
Written by Sam Fitzgerald, a MSc student in the Department of Pest-management and Conservation at Lincoln University.
