Yes… And No
Milk is a liquid food substance made by mammals in their mammary glands.
All species of mammal make milk to feed their young – and of course, we use the milk of some mammals in our daily lives Cows are the mammal that produces the milk most of us use, but humans also drink goat’s milk, sheep’s milk, yak’s milk, camel’s milk, and others!
It’s a vital part of life for mammals – it feeds the young of each generation. A young mammal without access to its mother’s milk isn’t likely to make it, unfortunately.
Birds produce something similar for their young too, but it’s not quite the same as mammalian milk!
Pigeons do indeed produce something similar to milk, and it does a similar job too – feeding their young. However, it doesn’t look much like the sort of milk a mammal produces! It’s not even a liquid either!
This substance is called crop milk. Unlike the liquid milk you’re used to, this is a semi solid substance. Like milk, though, it is extremely nutritious, and vital for the survival of young pigeons!
Crop milk is the only thing that a newly hatched chick can actually eat for the first few days of their lives, and they eat it for more than 2 weeks after birth too.
Pigeons may stop eating for a few days before producing crop milk to ensure that no food, like seeds, are present when making crop milk.
This is because the young won’t be able to eat anything but the crop milk. After a few days of crop milk, the young can eat small amounts of solid food mixed in with crop milk.
Eventually, they’ll be able to eat solid food!
As such, it is the single most important source of nutrition for a newly hatched bird – without it, they won’t survive.
Crop milk is important not just because it’s the only thing available to them, but because it is so packed with things a growing bird needs.
When analyzed, crop milk has actually been found to have more protein and fat than either cow milk or human milk does!
Unlike in mammals, which have mammary glands for the production of milk, birds produce this in something called the crop.
The crop is a part of the digestive system in birds. Other animals have crops and use them for the same purpose – for example, bees, leeches, and ants all have crops used for storing food in their bodies
However, not all birds have crops – for example, geese and owls don’t have them.
How Is Crop Milk Made?
Cells in the crop will start to make the crop milk. These cells fill with a fluid made by the pigeon.
Eventually, they slough off, ready for the pigeon to regurgitate them. The newborn chicks put their beaks inside the beaks of their parent to eat it!
Do All Pigeons Make Crop Milk?
Most bird species that have crops don’t actually use their crop to make milk.
Only pigeons, doves, Emperor Penguins, and Greater Flamingos have been observed to produce crop milk. However, all pigeons produce crop milk!