Commonly used funnel trap causes rostral damage in Lakes skink (Oligosoma aff. chloronoton ‘West Otago’)

Funnel trapping is recognised as a best practice method for lizard inventory and monitoring, and is considered safe for most lizard species when deployed correctly. However, we observed rostral damage to Lakes skinks (Oligosoma aff. chloronoton ‘West Otago’) following trapping using Gee's minnow traps with 1/8" mesh, a commonly used device for terrestrial lizards. Of 73 Lakes skinks captured over two distinct trapping sessions, 19 had damage (26.0%). One of two captured Mackenzie skinks (Oligosoma prasinum) also had damage. We suggest that damage was caused as interned lizards tried to escape through the mesh. No evidence of similar damage was seen for the smaller species caught, including McCann’s skinks (Oligosoma maccanni), southern grass skinks (Oligosoma aff. polychroma Clade 5), and Southern Alps geckos (Woodworthia ‘Southern Alps’). It may be that smaller lizards that can comfortably fit their snouts through the mesh were less affected, or that the behaviour causing the damage (i.e. ramming into the trap sides) was reduced for these species. In this instance, damaging behaviour may have been exacerbated by high within-trap temperatures, which can trigger escape responses in other lizards. In future, practitioners trapping for larger bodied skinks should consider using alternatives trap designs where possible (e.g. pitfall trapping), or test modified Gee’s minnow traps. If unable to alter trap type, additional ethical justification should be required when using Gee’s minnow traps for this species and potentially for other large skinks.