Testing and improving baiting technologies for the management of mice (Mus musculus) : a dissertation submitted in partial fulfilment of the requirements for the degree of Master of Applied Science at Lincoln University

Abstract

In New Zealand, mice are a pest of conservation and economic importance. The work presented here was aimed at testing and improving baiting technologies for the management of mice. The objectives undertaken were: (1) to determine whether cellophane wrapped baits have an increased attractiveness to mice, (2) to measure the palatability of baits containing an antifungal compound against baits without the antifungal compound, (3) to measure the palatability of FF213 paste bait, and (4) to determine whether bait palatability differs between domestic and wild mice. To test the attractiveness of cellophane-wrapped bait one mouse was allowed to feed on a wrapped bait while four wild mice in separate surrounding enclosures were observed for an hour. Results were collected using two methods; firstly time interacting with the bait as a percentage of the total, where time in the inner section of the surrounding enclosures was taken as a percentage of time when the middle mouse was interacting with the bait. Secondly, fifteen second counts, where observations of the mouse's location were taken every 15 seconds over one hour. Percentage data found all mice in all trials spent a higher proportion of time near the central mouse when the central mouse was presented cellophane-wrapped bait, compared with when it was presented unwrapped bait. However overall results where not statistically significant (F₁,₁₁₁= 0.72; P = 0.399). While 15 second count data found mice spent a statistically higher proportion of time in the inner section when the bait was unwrapped (X²₁,₂₃ = 5,26; P = 0.022). The results of this study reject the notion that wrapping baits in cellophane increases it attractiveness to other wild mice. Two-choice palatability trials showed that multi-species bait Ferafeed 213 had a significantly lower palatability than an EPA (experimental control )bait when tested on wild mice (trial 2: P=0.01, trial 3: P=0.002), though there was no significant difference for domestic mice. A significant difference (P=0.004) was also found between the palatability for wild and domestic mice, with wild mice being less accepting of baits compared to domestic-raised mice. Two-choice trials on the multi-species Erayz antifungal bait found no statistically significant difference in palatability for wild or domestic mice when compared to Erayz bait without the antifungal compound. There were also no statistically significant differences in palatability between domestic mice than wild mice and all individuals consumed some test bait. In conclusion the study found the cellophane type tested did not significantly alter the attractiveness of baits to wild-caught mice. Palatability trials found FF213 bait less palatable to wild-caught mice than the EPA standard, while domestic mice appear to be less discerning of baits. The results of this study also concluded that the addition of the antifungal compound did not alter the palatability of Erayz baits to wild-caught or domestic mice. While rodent control techniques in New Zealand have been developed primarily with rats as the target species, this study provides species-specific information focusing on wild caught mice, improving baiting technology for the future management of mice in New Zealand.