Winter 2024 Small Mammal Capture Summary

By March 1, 2024 Articles, Media

We monitor small mammal abundance twice annually (January and June) because our abundance of bobwhites tend to track small mammals very closely. Our technicians set a total of 1,176  Sherman traps across the Ranch for 4 consecutive nights (Jan 10-14) resulting in 4,704 total trap-nights of effort. This surveillance showed our rodent abundance remains quite low relative to our long-term data. Of note, our “rodent of interest” (cotton rats) are essentially absent from our landscape. Note in the graph how cotton rats irrupted in 2015-16, but have remained at only low levels since then. Specifics included:

  • A total of 350 small mammals were captured among 10 species;
  • 241 unique individuals were captured;
  • 2 species: Peromyscus spp. (27%) and Merriam’s Pocket mouse (25%) accounted for 52% of total captures;
  • 3 species: House mouse (16%), Hispid Pocket mouse (13%) and Plains Harvest mouse (10%) accounted for 39% of total captures;
  • Only 1 cotton rat (Sigmodon hispidus) was recorded.

by Dan Foley