Jico Deer Mouse (Habromys simulatus) is listed as Critically Endangered because it is known from only two subpopulations: one is likely now extinct, and the other has extremely low population numbers (less than or equal to 50). Most of the mature individuals from are in one subpopulation. If more habitat continues to disappear, this species may also be considered Critically Endangered under criterion B.

Available at: https://www.iucnredlist.org/species/9611/22376731