Factors affecting 1080 pellet bait acceptance by house mice (Mus musculus)By P. Fisher and A.T. Airey
DOC Research & Development Series 306. 22 p.
What's it about? Avoidance of 1080 (sodium fluoroacetate) could be one of the main reasons why multi-species control operations sometimes do not produce high reductions in wild house mouse (Mus musculus) populations in New Zealand. This study investigated how the concentration of 1080 in pellet bait affects acceptance by mice; whether pre-feeding with non-toxic bait mitigates mouse avoidance of bait containing 1080; and whether a non-toxic bait containing a masking agent is acceptable to mice.
Wild-caught mice demonstrated very low acceptance of, and subsequent low mortality (25%) from, baits containing 0.08% 1080 in a two-choice laboratory test. In a second test, mice ate comparatively more pellets containing 0.001% 1080, but there was no resulting mortality and the non-toxic alternative pellets were still significantly favoured. Pre-feeding for 3 days with non-toxic pellets did not improve the low acceptance of 0.15% 1080 pellet baits by mice.
In two of the three two-choice tests, the intake of all food by mice was significantly reduced for 2 days following the introduction of 1080-treated food. This ‘drop feed’ effect was followed by an increase, mostly of non-toxic food, in daily intake over the next 3 days, to return to eating similar amounts to those measured before the introduction of 1080 (and to daily food intakes of control mice). Non-toxic bait was strongly preferred over two different types of non-toxic bait containing a masking agent.
We suggest that avoidance of 1080 by mice is mediated by conditioned taste aversion. However, masking the taste of 1080 may not be effective if mice are micro-sampling and learning to associate sublethal poisoning effects with any distinctive taste. Improvement of bait efficacy may involve developing baits that delay the onset of symptoms of 1080 poisoning; or pre-feeding with baits containing a non-toxic substance with similar taste and/or odour to 1080.
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The above new publication is now in press and can be downloaded from:
http://www.doc.govt.nz/upload/documents/science-and-technical/drds306entire.pdf (233 KB)
