Lizard monitoring in the extended wildside, Banks Peninsula, Canterbury

Abstract

Long-term monitoring programs are important to document changes in populations over time and to determine what other factors, such as predator control, may be influencing any changes. There are current predator control goals on Banks Peninsula by Pest Free Banks Peninsula (PFBP) to eradicate stoats, feral cats, and possums by 2024 and to be nationally predator free by 2050. However, there is no point controlling pests if there isn’t parallel monitoring of vulnerable native species, such as lizards. Our study has two aims: (1) to establish baseline date for lizard populations in the Wildside area of Banks Peninsula, and (2) to contribute to ongoing long-term monitoring with biannual surveys in January and April. We targeted five lizard species: Woodworthia brunnea, Naultinus gemmeus, Oligosoma polychroma Clade 5, O. lineoocellatum and O. maccanni. Monitoring was done across three habitats (grass, rock and bush edge) using artificial cover objects (ACOs), tracking tunnels, a 50m walk, a 5-minute vegetation scan and opportunistic searches. Only two species, W. brunnea and Oligosoma sp., were observed during this survey. Our work showed that ACOs provided the most observations, especially for W. brunnea. Oligosoma sp. were less frequently observed, possibly due to being day active and not using shelter. The tracking tunnels showed mice to be the most abundant mammal (22-37% of tunnels), also occurring where lizards were detected in tunnels. Further effort is needed to monitor lizard species not observed in this study, as the lack of observations does not equate to their absence.