Video footage postage by the Science Channel left many viewers shocked initially, as it appeared to show a flamingo digging its beak into another’s, who in turn has its beak pointed at a baby flamingo’s mouth, where something like blood appears to be dripping.
However, what is seen in the here is far from a fight – it is actually two flamingo parents feeding their baby. Parent flamingos produce crop milk, red in colour, in their digestive tracts and regurgitate it to feed their young.
Crop milk is a secretion from the lining of the crop, a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion in many birds and invertebrates. It is found among all pigeons and doves (where it is referred to as pigeon milk).
An analog to crop milk is what is secreted from the oesophagus of flamingos (seen above) and the male emperor penguin.