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
