**5. Conclusions**

We analytically, physiologically, and biologically validated two EIAs for measuring FCMs in deermice. Although we used identical sample processing and extraction methods for laboratory samples, this was not the case with field samples so direct comparisons should be made with caution. Nevertheless, both field studies demonstrated similar temporal patterns, so they provided biological validation for the two EIAs. Although we acknowledge low sample sizes, our study is the first to provide validation evidence for EIAs that can quantify FCMs in deermice.

**Author Contributions:** Conceptualization, A.E. and R.B.; data curation, A.E.; formal analysis, A.E.; funding acquisition, A.E. and R.B.; investigation, A.E. and R.B.; methodology, A.E. and R.B.; project administration, A.E.; resources, A.E., R.P., and R.B.; software, A.E.; supervision, A.E.; validation, A.E.; visualization, A.E.; writing—original draft, A.E.; writing—review and editing, A.E., R.P., and R.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was partially funded by the Wildlife Biology program at the University of Montana, Interdisciplinary Collaborative Network, Montana Institute on Ecosystems and the Associated Students of the University of Montana.

**Acknowledgments:** We thank Grant McClelland and Graham Scott of McMaster University for providing us with the laboratory-bred deermice that originated from Nebraska, USA. We thank Michael Sheriff for all his advice in setting up the study, for partially funding laboratory analyses and for allowing the primary author to complete assay work at his laboratory space at Pennsylvania State University. We also thank Catharine E. Pritchard for her laboratory and editorial assistance, Ben Dantzer from the University of Michigan for shipping samples to us at Pennsylvania State University and Angela Luis from the University of Montana in Missoula for her general feedback and support during the study. Additionally, we thank the private cattle ranch owners and Montana Fish, Wildlife and Parks for allowing us access to their lands where the fieldwork took place, and all the volunteers that assisted with field and lab work at the University of Montana. Lastly, we thank the anonymous reviewers for their helpful comments on previous versions of this manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
