Among the species known to exist, only the non-neotropical members of the genus Dryocopus and the great slaty woodpecker (Mulleripicus pulverulentus) are larger-bodied.

Juvenile Magellanic woodpeckers resemble females of the species, but have a smaller crest and have a browner tinge to their plumage.

[7] Magellanic woodpeckers inhabit mature Nothofagus and Nothofagus-Austrocedrus forests, where they feed mainly on wood-boring grubs and adult beetles (Coleoptera), as well as spiders.

Occasionally, other foods may supplement the diet, including sap and fruits, as well as small reptiles, bats, and the eggs and nestlings of passerines.

Breeding pairs are highly territorial and commonly try to aggressively displace and even attack conspecifics, sometimes doing so cooperatively with the juveniles that they had raised in prior years.

The species commonly co-occurs with the Chilean flicker (Colaptes pitius) and the striped woodpecker (Veniliornis lignarius), but does not directly compete with them due to differing body sizes and habitat and prey preferences.

[10] These woodpeckers commonly feed in pairs or small family groups and are very active in their food searching; they spend most of the daytime looking for prey.

Once the snow disappears from the ground in spring, Magellanic woodpeckers look for prey on humid lower tree trunks.

In Tierra del Fuego, Magellanic woodpeckers forage on decaying and dead trees around ponds hosting the introduced American beaver (Castor canadensis).

The nesting holes are located at differing heights depending on the tree species and local habitat characteristics.