Small mammal surveys often involve mark-recapture trapping. The gold standard of small mammal traps are the Sherman folding live traps. If properly set, mortality in these traps is generally very low for most species of small mammals. Traps can be arranged in a linear transect for a quick inventory of species present on a site, or set in a grid or web pattern with known spacing to allow the determination of density. Most small rodents are readily caught in live traps, but an understanding of small mammal ecology will help determine the most effictive timing of sampling and siting of traps to ensure project success.

Trapping Grid design. From Ecological Census Techniques, 2nd edition by William J. Sutherland.

Trapping web design. This design permits the placement of 144 traps in concentric circles of ever-larger diameter.

Sherman live trap.

Density estimation requires mark-recapture methods where animals are marked upon capture (often with uniquely-numbered ear tags) and the exact location of capture is noted. Recaptures also note the individual captured and the recapture location. The rate of new captures to new captures allows the estimation of population size, and movement data allows for an estimation of the size of the area that is effectively being sampled. Combining these two (population sizeand sampling area) allows the determination of a density value for the species in question.

Numbered Monel ear tags.

Some species of small mammals require different sampling techniques. Shrews, for example, are often too small to trigger a box-type live trap, and are generally captured via the use of pitfall traps (cups buried in the ground, often near specific habitat features).  Flying squirrels require that traps be placed in trees (and slightly larger traps may be required).

White-footed mouse, Peromyscus leucopus

Plateau Ecological has the experience and the ecological knowledge necessary to effectively and efficiently sample small mammal populations. Data we collect can be used to evaluate the effectiveness of habitat treatments, assess the presence or absence of rare species on a site, or address any number of other questions related to the small mammal community. We are experts at identifying small mammals of the southeastern United States including those of Tennessee, Georgia, Alabama, Kentucky, and North Carolina. Let us assist you with your small mammal sampling needs. Contact us today!