They are mostly whitish below, with a buffy tinge on the throat, tiny dark spots on the sides of the breast, and blackish brown streaks on the flanks.

[5] The San Cristóbal mockingbird mostly forages on the ground for terrestrial arthropods but also takes fruits and berries from low vegetation.

It runs a short distance, briefly opens its wings to two-thirds of full extension, then extends them fully to a position just above horizontal.

[6] The San Cristóbal mockingbird nests from January to April at low elevations and to later at higher ones.

The species builds a bulky nest of twigs lined with grasses in the crotch of a tree, usually 4 to 5 m (13 to 16 ft) above the ground.

The San Cristbal mockingbird sings a "[l]oud, melodious and disjointed territorial song typical of [its] genus.