Small Mammal Trapping at Fish Slough

Not knowing much about what small mammals are present in Fish Slough, I set out some Sherman live traps to see what I could get. It has been demonstrated that 84% of the species present in an area can be captured over the first three trap nights, but a fourth night only increases the estimate by 2%, so I left the traps out for three nights and two days. Since the weather isn't very hot during the day this time of year, I left the traps open during the days as well as nights. The traps were baited with peanut butter and oats and cotton balls were provided for bedding.

I ended up capturing 10 individuals of 4 species: Sorex vagrans (vagrant shrew, 2), Microtus montanus (montane vole, 1), Reithrodontomys megalotis (western harvest mouse, 3), and Peromyscus maniculatus (deer mouse, 4). Not a bad selection for the middle of winter! The shrews were a particular surprise, since they're not often captured in box-style traps.

Sherman trap	Sorex vagrans
Microtus montanus	Reithrodontomys megalotis
Peromyscus maniculatus	cute mousey face