Once, when we had a look at the actual zinc content in the glue in those paper rolls,
and then “borrowed” the nutritional requirements for zinc in chickens; presuming
that the requirements in a parrot would be similar, we were able to show that if a
parrot ate toilet paper exclusively with that zinc containing glue, there would still be
a need for zinc supplementation to meet the nutritional requirements for the bird.
(Speer 2010, Veterinary Information Network)