Discussion
It is our understanding that the first fencing used for reptiles and amphibians was for drift fence as a common sampling technique for herpetofauna studies. We believe it is from this application where other fencing guidance and best practices have been developed. As guidelines have developed it shows that recommendations have moved away from highly transparent, mesh type materials towards more opaque solid barriers.
It is our understanding that the use of readily available cheap construction materials such as silt fence, shade, and hardware cloth has been continually recommended despite the absence of any research to test its suitability, effectiveness or assess animal behaviours when they encounter such materials. Only in the most recent guidance has animal behaviour been studied and highly opaque / solid fencing been highlighted as a more suitable barrier type. Transparent mesh products have ceased to be acknowledged as appropriate.
One factor that is raised for consideration between solid opaque barriers is when drainage is a concern. Recommendations suggest using pre-perforated solid products is a solution along with and should be considered before any mesh product. If mesh has to be used, then this should be used sparingly and with holes no larger than 3mm to minimize the risk of animals becoming entangled.
There are also suggestions for the use of different material types depending on the duration of the project and application. Lighter grade products may be more suited for short term projects whereas heavier grade products should be utilized for long term applications.
Shelters have also been identified as a useful addition to a fence line to help provide animals refuge as they move along. The details of these are yet to be determined and require further research.
We identified some significant difference in fence height above ground ranges for a few species’ groups. Due to this we have split our recommendations into small & large species variations for some species. Further research needs to be conducted to improve the understanding of fencing methods for unique species and localized biological knowledge should always be considered.
Despite the variations and considerations that need to be made for species variability (as not all species on all continents are the same and will respond to fences the same) we believe these recommendations will be suitable for most herpetofauna species currently and commonly managed with fencing as a conflict management tool.
Recommendations also take into consideration the presence of other species that may not be the “target” for the project. If a project is focused on controlling the movement of turtles, the chances are there may be other herpetofauna and other wildlife in the same habitat that might benefit from the installation of a fence or barrier. As it is known these species commonly share the same habitat types, we feel it would be advantageous to include the anti-climb lip on all barriers.  When determining recommended heights, we have also taken the presence of other species into consideration. A slight increase in height will only positively impact the fences over all functionality without negatively impacting the potential fence cost, installation method of long-term maintenance. We have also standardized the depth of the fencing to be installed below ground along with the inclusion of an anti-dig lip for the same reasons.
Some guides also suggest an anti-climb top lip to be folded over, but this is also inconsistent and may only be recommended for certain species. The exact shape of this lip also varies and although more research needs to be done on this, we have based our recommendations on the most effective shape for most species known to date.
Some guides suggest folding an anti-dig lip in the ground, but this is inconsistent across all of them.
We recommend that in the absence of best practice guidance and for ease of wider implementation that anti-dig and anti-climb lips be applied to all fences
The fence profile or shape is represented as a bold black line comparable to the shape of the letter “C”. Fences can be installed on their own as a “free-standing” barrier or attached to existing fences. Irrespective of the installation method the measurements, features and considerations should remain the same. The illustrations do not induce details of any supportive posts or fixings that may be required to ensure the fence is complete. The measurements shown are minimum requirements appropriate to the specific fence barrier component for the listed herpetofauna only. These recommendations are just recommendations and should be considered as such.