Cereal aversion in behaviourally resistant house mice in Birmingham, UK

Area of Science:

• Zoology
• Animal Behaviour
• Genetics

Background:

• Behavioural resistance in house mice (Mus musculus) to rodenticides was first observed in Birmingham in 1986.
• This resistance phenomenon involves mice actively avoiding bait stations, rather than physiological resistance to the toxins.
• Understanding the drivers of behavioural resistance is crucial for effective pest control strategies.

Purpose of the Study:

• To investigate the food preferences of behaviourally resistant West Midlands house mice (WMBR) compared to normal (BC) mice.
• To determine if the observed food aversions in WMBR mice have a genetic basis.
• To identify specific food components that WMBR mice avoid, potentially explaining their resistance to rodenticides.

Main Methods:

• Comparative food preference trials were conducted using nine different food types in bait boxes.
• Experiments were performed in both field (natural environment) and laboratory settings.
• Offspring of WMBR and BC mice were tested to assess the heritability of food preferences.

Main Results:

• WMBR mice exhibited a consistent aversion to cereal-based foods (e.g., canary seed, wheat, pellets) in both field and laboratory conditions.
• This aversion to cereals was also observed in the offspring of WMBR mice, indicating a genetic component.
• Normal (BC) mice showed varied preferences, with some populations exhibiting food neophobia (avoidance of novel foods).

Conclusions:

• The aversion to cereal-based foods in WMBR mice is strongly suggested to have a physiological and genetic basis.
• This genetically determined cereal aversion provides a survival advantage against common cereal-based rodenticides.
• WMBR mice possess innate behavioural traits that confer resistance to specific rodenticidal poisoning regimes.