The Blackish Cinclodes is known as the Tussac-Bird in the Falkland Islands where it is a well known and visible component of the avifauna. Tussac is the name given to the bunchgrass common on the islands. Here the Blackish Cinclodes can be found in a variety of habitats including the coast, as well as grassy areas, near settlements and even around seabird colonies. Although still widespread, this species has suffered from introduced rats and cats on the Falklands and its distribution and numbers are depressed from historical populations. The Blackish Cinclodes is the only member of the genus that is entirely dark, lacking white on the throat, supercilium or underparts. The well known form of the Falklands is the nominate subspecies, another taxon (maculirostris) is found in coastal areas of southernmost Chile and Argentina and this form is rather poorly known. It also is all dark, but a different tone of brownish-black than the nominate, and the bill has a noticeable pale area at the base of the mandible. Different species of Cinclodes can be visually very similar, and it is likely that these two subspecies may actually be separate species, but information on the voice of maculirostris is still lacking. Genetic work has shown that the nominate form is most closely related to the Bar-winged Cinclodes (Cinclodes fuscus).