Responses by wild house mice (Mus musculus) to various stimuli in a novel environment

Abstract

House mice (Mus musculus) pose a threat to the native flora and fauna on islands, and can cause significant damage wherever they have been introduced. Methods used to eradicate invasive rodents, like house mice, at high population densities may not be appropriate for intercepting them at lower densities. A better understanding of the immediate behavior of house mice when first introduced to a novel environment would help managers develop effective biosecurity techniques to protect against new invasions. To address this problem, we conducted a controlled laboratory experiment that simulated an invasion by wild house mice into a novel environment. We quantified and compared the immediate behaviors of wild house mice (n=40) by testing various odors and other attractants, including odors (e.g., foods and conspecific), shelter, water, and a control. There was a significant difference in mouse responses to these treatments (P≤0.0001). We found that the most common immediate reaction of invading mice was to seek shelter in a den box (μ=47.7 box entries) rather than responding to the other potential attractants presented. Secondarily, the mice were interested in some food scents, particularly bacon grease (μ=18.3 box entries), peanut butter (μ=17.0 box entries), and cheese (μ=14.5 box entries). The sex of the mouse did not influence their responses to odors and attractants (P≥0.243), however, we noted that females visited male feces and urine odors (μ=17 visits) more than males visited female feces and urine odors (μ=11 visits). Fewest visits were to the empty box (μ=8.0 box entries) and the water box (μ=5.1 box entries) Based on our findings, we surmise that a secure den box which included certain food odors might entice and hold mice in a restricted area for a short duration in a novel environment. If done properly, this arrangement could be utilized for early detection and response to newly-invading house mice.