As it existed together with C. leucognaphalus on Puerto Rico, it possibly occupied a different ecological niche as the latter, and was perhaps rather common in the island's lowlands.

[2] The earliest residues of the crow were found in 1916, in the karst cave Cueva San Miguel near Morovis, Puerto Rico.

It was a right ulna (AMNH 4925), which Alexander Wetmore described in 1920 as a holotype for his first description of the species C. pumilis.

Wetmore did not comment on the etymology of the epithet pumilis, which means "dwarfish" in Latin.

[2] In Puerto Rico, it is only known from lagerstätten; on St. Croix, it was found on a hearth from the Pre-Columbian era.