Pigeons are among the few bird species with the fascinating ability to produce a special substance called crop milk to feed their chicks. Unlike mammalian milk, crop milk isn’t produced by mammary glands but forms in the crop—a pouch in a bird’s throat that aids in food storage and digestion. Both male and female pigeons secrete this highly nutritious substance, ensuring their chicks, or squabs, receive a rich source of proteins and fats essential for rapid growth during their early days.
What makes crop milk even more remarkable is how rare this ability is among birds. Besides pigeons and doves, only a few species, such as greater flamingos and emperor penguins, are known to produce a similar substance. While flamingos produce a red, fatty liquid in their upper digestive tract, emperor penguins create a milky secretion in their oesophagus to nourish their chicks in harsh Antarctic conditions.
For pigeons, crop milk is vital in the first week of a chick’s life. Parents regurgitate it directly into the chicks’ mouths, providing sustenance until they are old enough to eat softened seeds and grains. This extraordinary adaptation highlights nature’s ingenuity in helping species thrive in diverse environments.