Masked grass finch needs charcoal?

[finchbob]

I found an article that says masked grass finches need charcoal, article is here: http://www.petcaregt.com/birdcare/maskedgrassfinch.html

I didn't know they needed charcoal, assuming this is true. Out of zebras, bengalese, hecks grass finch and cherry finches, do any of these also require charcoal?

[L in Ontario]

I provide avian charcoal mixed with oyster-shell grit to all my finches.

[Sally]

I also supply bird charcoal to all my birds--their mineral cup has a mixture of oystershell grit, charcoal, eggshells, trace mineral powder, and they can select what they want. Maybe the reason that site says they need charcoal for breeding is because some birds will carry pieces of charcoal into their nests.

[Finch Fry]

Cuttle bone, charcoal and a general powdered trace mineral mix is in every cage for every finch I own.