House mice (Mus musculus) are a widespread pest throughout New Zealand habitats, including forests and subalpine tussock areas. Some standard rodent-baiting operations are unsuccessful in controlling field populations of mice, and the possible reasons for this needs to be determined. This research investigated avoidance responses of mice to toxic baits, and aimed to identify the particular bait characteristics that mediate any avoidance. In a factorial design trial, 96 wild-caught mice were housed individually and presented with one of 32 possible bait types, for 10 nights. Bait types were all combinations of five factors: (1) toxin type (1080 or brodifacoum); (2) bait (No. 7 or RSS); (3) presence or absence of green dye; (4) presence or absence of mask/lure (0.3% cinnamon); and (5) bait size (2g or 12g). Other than toxin, there was no effect of bait characteristics (i.e. bait, size, dye, or lure) on bait avoidance or acceptance. All brodifacoum baits were eaten, resulting in 100% mortality. However, 1080 baits were avoided, resulting in only 8% of mortality. This marked avoidance of 1080 baits by mice is likely to have been the cause of control operation failures, and until new methods are developed to improve 1080 bait acceptance in mice, this toxin should not be used for mouse control operations.
|Author||O'Connor, C., Morriss, G. and Murphy, E.|
|Secondary title||13th Australasian Vertebrate Pest Conference|
|Place published||Wellington, NZ|