Density estimation for small mammals from livetrapping grids: rodents in northern Canada

Researchers found that Efford's maximum-likelihood (ML) estimator generally provides more accurate density estimates for small mammals compared to conventional boundary-strip methods, especially in boreal forest ecosystems. The study analyzed mark-recapture data from 104 trapping sessions across Kluane, Yukon, and tundra areas of Herschel Island and Komakuk Beach, northern Yukon, involving 6,145 individuals. While Efford's ML estimator produced density estimates smaller than boundary-strip methods in boreal forests, it showed varying accuracy in tundra environments—underestimating at low densities (<1.5/ha) but performing better at high densities (25/ha). The findings highlight the need for careful selection of estimators to ensure robust population density assessments, crucial for management agencies and ecological studies.

Krebs, C. J., Boonstra, R., Gilbert, S., Reid, D., Kenney, A. J., & Hofer, E. J. (2011). Density estimation for small mammals from livetrapping grids: rodents in northern Canada. Journal of Mammalogy, 92(5), 974–981. https://doi.org/10.1644/10-mamm-a-313.1