Salvin's spiny pocket mouse carries seeds in fur-lined cheek pouches and searches for seeds of woody plants. In the dry forests of Área de Conservación Guanacaste, it has also been reported caching seeds.
Its back and upper sides are brownish gray, and its underside is cream white. Fur-lined cheek pouches carry seeds and insect pupae.
In ACG dry forest, it searches for, caches, and eats mature seeds from woody plants. The account also reports moth pupae and possibly other dormant insects in its diet.
An extinction-risk assessment has not been added yet.