East London zoo free birds and birds in cages

Zooty enjoyed feeding the birds at the East London zoo - he fed the birds peanuts.  He fed many animals at the zoo the peanuts that are available for purchase at the zoo kiosk, but he particularly enjoyed feeding the birds, the quite tame doves, that hang around the zoo - although he did feed the birds that were in cages too.  I wonder if the birds in the cages feel sad when they see those free birds so close to them, in the same zoo, yet free?
(post by Terry)