Investigating what role house mice play in island ecosystem food webs
The house mouse (Mus musculus), after humans, is the most ubiquitous mammal on the globe, and has adapted to a wide range of environments, colonizing every continent except Antarctica. Plasticity in diet is one of the key adaptations that allows house mice to survive and thrive across various regions and climates. House mice are considered a generalist omnivore and consumes a diverse array of arthropods and vegetative material. However, on islands, mice have exhibited surprising prey-switching behavior, in some cases attacking and depredating breeding seabirds that are magnitudes larger than the mice themselves. Despite increasing observations of seabird depredations by house mice, it remains unknown if seabird consumption constitutes an incidental or foundational component of mouse diet on islands—which represents a critical knowledge gap of house mice behavior and ecology. Specifically, this gap underscores the need to understand adaptive capacity of house mice in insular ecosystems and the resulting ecological consequences of that adaptability.
The novel behavior of seasonal prey-switching to island avifauna by house mice often occurs when other preferred food sources, such as arthropods and seeds, are limited. In particular, this prey-switching behavior has only been documented when mice are the sole (introduced) predatory mammal in island ecosystems. Under these circumstances, the species’ effects on insular food webs may be amplified as house mice shift to a predatory behavior more commonly associated with Rattus spp. However, when house mice co-occur with Rattus spp., evidence suggests that these rodent species collectively participate in niche partitioning. Thus, prey-switching by mice could be very important in top-down control of island ecosystems, given that invasive rodents are typically the only vertebrate predators in these ecosystems. Moreover, with the increasing use of rodent eradications to restore island ecosystems, predicting both the nature and magnitude of direct and indirect ecosystem effects that follow eradications is critical. For example, if house mice effectively operate as a top predator on islands, their eradication could result in a sudden and unanticipated release of prey species, which could be challenging if mice were also controlling other problematic species (e.g., invasive plants or agricultural pests). Few studies have examined the diet and trophic niche of house mice on island ecosystems; consequently, the broader island ecosystem effects of this species are largely unknown.
Our Objective | Conduct a global study of islands to investigate the trophic position of invasive house mice and understand the broader effects of house mice on insular food webs.
Methods | Use amino-acid compound specific isotope analysis (CSIA) and bulk tissue stable isotope analysis in tandem of house mouse hairs to infer trophic position and diet.
Methods | Use amino-acid compound specific isotope analysis (CSIA) and bulk tissue stable isotope analysis in tandem of house mouse hairs to infer trophic position and diet.
Meet Our Team
Our project involves the participation of numerous university labs, research groups, and non-profit organizations.
Get on the map – and join our growing list of collaborators!
Join our project! If you work on island(s) with house mice (Mus musculus) as the only invasive rodent present, let us know and fill out the form below! We hope to obtain at least 10 house mouse hair samples per island in this study.
Download the house mouse hair collection protocol here.
As a note: Participation in this project is voluntary and we do not assume responsibility for completing the needed permits, licenses, or other paperwork that may be required by your respective institutions. We will assist you in preparing and shipping the house mouse hair samples.
Download the house mouse hair collection protocol here.
As a note: Participation in this project is voluntary and we do not assume responsibility for completing the needed permits, licenses, or other paperwork that may be required by your respective institutions. We will assist you in preparing and shipping the house mouse hair samples.