Which bird feed milk to its baby

What Is Pigeon Milk? Do Birds Produce Milk?

Some birds produce crop milk to feed their young.

Producing milk to feed offspring is the domain of mammals like whales and humans. However, the trait is not only limited to mammals. The flamingo, pigeon, and male emperor penguin are the three species of birds that produce a milk-like substance known as crop milk or pigeon milk to feed their young ones. Unlike mammals who produce milk through the mammary glands, lactating birds regurgitate crop milk. Pigeon milk contains immune-enhancing and antioxidant factors, and just like mammalian milk, it helps to build the immune system of the young ones.

What Is Crop Milk?

The crop is located between the esophagus and the upper part of the bird’s stomach. Its core responsibility is to moisten the food before digestion. Pigeons begin producing crop milk two days before hatching, and this continues until the squabs are ten days old. Squabs that feed on pigeon milk have a better chance of surviving and will grow faster than those who do not. On one occasion, pigeon milk was fed to chicks, and the growth rate was 38% higher than other chicks. Both the male and female pigeons produce crop milk.

How Do Birds Produce Milk?

Pigeons normally use their crops to store food, but the crops change during lactation in response to changes in hormones and revert to the non-lactating state after the lactation period. Crop milk is produced by fat-filled cells; they are rich in protein, minerals, fats, and antibodies. Birds differ from mammals in that they do not have sweat glands, but they can accumulate fat in their skin cells which act like sweat glands. The production of pigeon milk is attributed to the ability of the skin cells to accumulate fat.

Comparison To Mammalian Milk

Crop milk does not really resemble mammalian milk in that the former is a semi-solid substance that looks more like pale yellow cottage cheese. It contains higher levels of fats and proteins than human and cow milk. The antioxidant and immune boosting factors also increase the chances of the young ones surviving. Just like human milk, pigeon milk contains antibodies and some bacteria. While the mammalian milk is an emulsion, crop milk is a suspension of fat rich and protein-rich cells that detach from the crop lining. Prolactin is the hormone responsible for lactation in both mammals and lactating birds.

Victor Kiprop in World Facts

What Is Crop Milk?

Zoltán Vörös / Flickr / CC by 2.0

Crop milk is a semi-solid, crumbly excretion high in fat and protein that some bird species feed to baby birds during the first days after hatching.


KRAHP milk (rhymes with hop silk, top ilk, and stop bilk)

Nutritional Information

Unlike mammalian milk, crop milk or bird milk does not have any calcium or carbohydrates. The exact composition of crop milk varies depending on the bird species and the parent bird's diet. Generally, it is a gooey, crumbly substance similar in consistency and texture to the curds of cottage cheese.

Fun Fact

Unlike in mammals, crop milk is not generated by mammary glands, nor do young birds suckle on a teat to feed.

Crop milk ranges in color from whitish to yellow, gray, or beige, and contains a variety of substances, including:

  • Fat
  • Protein
  • Minerals
  • Antioxidants
  • Antibodies
  • Bacteria

Crop milk is only fed to young birds for a few days until they are able to digest other foods, and parent birds may gradually mix adult food in with the young birds' diet to wean them off crop milk. To feed on this unique milk, young birds stick their bills into their parents' mouths to stimulate the production and release of the substance. In some species, such as pigeons, both male and female birds can and do produce crop milk to care for their young. In other species, only one gender may produce this food, but it could be either the male or female parent. For example, male emperor penguins produce crop milk, but females do not.

Because the milk not only contains nutrition for the young birds but also has immune-building properties with antioxidants and antibodies from the parent birds, it is believed to play a significant role in the developing health of young birds. Further detailed study and analysis of different types of crop milk and the birds that produce it is needed to determine the exact role it plays in the diet of young birds. Ornithologists are also interested in how more or less crop milk may affect the development and maturity of chicks and how their survival rates may differ from other birds.

Birds That Produce Crop Milk

All pigeons and doves feed their young crop milk. For these species, the milk contains sloughed off, liquid-filled cells from the inside of the parents' crop. The crop switches from part of the parents' digestive system to milk production just a day or two prior to the eggs' hatching, a switch believed to be caused by hormonal changes. During that time, the parent birds may cease eating altogether so there is no seed in the crop, which very young birds would be unable to digest. After several days of feeding young pigeons milk, the hormone levels taper off and the crop ceases to produce as much milk. At this time, the young birds are better able to digest seeds, insects, and other foods regurgitated by their parents.

Flamingos produce bird milk through glands along the digestive tract. Young flamingos eat this milk until they have developed the mature filter-feeding apparatus in their bills to allow them to feed on solid food. It takes roughly two months for young flamingos to develop well enough to eat mature food, and until that time, they feed exclusively on crop milk. While they are eating crop milk, however, they may still practice feeding as they learn how to use their bills, but they are not ingesting enough mature food to meet their nutritional needs.

Male emperor penguins will also generate a milk-like substance from the esophagus to feed young chicks after hatching. This is especially critical if the fishing females are late returning from the ocean with food to regurgitate. This type of feeding generally only lasts a few days, and after the females have returned, they alternate hunting duties with the males and are able to feed chicks regurgitated fish instead of relying on crop milk.

Alternative Names

While the term crop milk is universally accepted to describe this unusual part of a baby bird's diet, it is also occasionally called pigeon milk, pigeon's milk or bird milk. These terms can be slightly misleading, however. Pigeon or pigeon's milk would seem to imply that only pigeons produce this substance, while bird milk makes it sound as if all birds offer their chicks a type of milk. Neither of these is true, but birders who know the details about crop milk understand how important it is to baby birds, no matter what it is called.

90,000 They feed on their own blood and "bird's milk". From morning to evening

They feed on their own blood and "bird's milk"

Flamingo, when feeding his only chick, gracefully bends over him, slightly open beak, and food concentrate flows from the beak into the chick's mouth - a very nutritious broth: it contains a lot of proteins and 23 percent of blood. How blood gets into this strange "bird's milk" is still not clear.

Bird's milk has long been a symbol of the impossible. "Shall I give you some bird's milk?" - they say to a person who wants too much.

But now, after research done by ornithologists, this expression should be used with some caution. Many different curiosities in nature. There is also "bird's milk" among them. And you don't have to go far for it. Look at what pigeons feed their chicks - "bird's milk."

Newborn chicks do without nipples: they insert their long beaks into the throat of an adult pigeon and receive a portion of "bird's milk".

Shortly before the chicks hatch, a white mushy substance forms in the crop of the parent pigeons. It is called "goiter" or "bird's milk". In the goiter of domestic pigeons, “milk” is released for eighteen days, then the chicks switch to another diet. In wild pigeons, the "milk period" is longer.

Penguins, emperor and royal, also pamper their children with "bird's milk": it is produced in sufficient abundance by the esophagus and stomach of penguin parents - both male and female. "Milk" is nine times more nutritious than cow's: 60 percent protein and 28 percent fat!

In the sea, penguins only hunt for fish. And all the free time from hunting is spent on the shore. They gather here in large flocks. All together it is easier for them to endure the winter cold. And the winter in Antarctica is terrible: frosts are below eighty degrees. And snow storms. Yes, such that it’s better not to stay alone in such a storm: a mad wind will instantly knock you off your feet and pile a hundred kilograms of snow on you. The penguins know this. And when the storm begins, they gather in a heap and closely press against each other. It turns out a circle of penguins. Scientists have named it "turtle". The "turtle" spins all the time and slowly crawls where the wind blows. Outside, a snowstorm is raging, the frost is cracking, and inside such a circle it is warm, like in the summer in Africa. Thirty-six degrees! The storm will end and the penguins will disperse.

And in such and such a frost, penguins hatch chicks! True, where they “nest” at this time, the frosts are “small” - only 33 degrees. But snowstorms and strong winds that blow here all the time freeze the birds. How come their eggs don't get cold?

Penguins lay an egg on their paws. And so that it does not freeze from above, they cover it with a downy “blanket” - a special fold of skin on the belly.

First, the penguin holds the egg. Then the father penguin. But he does not just come and take the egg for himself, but bows to the penguin for a long time, flaps his wings, trembles with his tail - he is very worried. He himself looks at the egg, touches it with his beak and sings a special song to her: they say, go, dear, rest, I will replace you. And the penguin doesn’t have to be persuaded for a long time. She was very hungry: while holding the egg on her paws, she did not eat anything [19] . It's high time to refresh. And she leaves. For two months or more. To the ocean for fish. Sometimes he will leave for a hundred or two hundred kilometers, but he always finds his way back.

While the mother is hunting in the ocean, the baby penguin usually pecks out of the father penguin's bosom. It has a long thick down, like a fur coat. But for a long time, 40-50 days, the baby hides from the cold in his father's pocket, and then in his mother's, when she comes to replace her father.

The baby penguin, as soon as it gets out of the shell, asks for food. If the mother has not yet returned, the father feeds him "bird's milk".

Just imagine what a great feat it is to raise penguin chicks in Antarctica!

While the penguin was caring for the female, while she laid an egg for him, while she hunted in the ocean for 60-70 days, while the chick “was standing”, and then walked with the chick on its paws to the place where the flock hatches the chicks, after all, a hundred days have passed! And for a hundred days the penguin did not eat anything. It is not surprising that he loses weight almost twice during this time.

But now - finally! - a female comes and looks for her male in the pack. The task is also not easy: there are thousands of birds in the penguin colony (the largest once counted twelve and a half thousand penguins!). And she comes not alone, but hundreds of females approach the abandoned males in a solemn procession. There is a lot of noise and shouting, a lot of unfortunate misunderstandings happen before each finds her lawful spouse.

Here he hands her an expensive child (literally “expensive”, considering all the cares and “expenses” spent on it) from paw to paw. And he hobbles to the sea, to hunt. The mother feeds the chick at first every hour. But an amazing thing: the penguin brought only a kilogram of half-digested fish in her stomach. The chick is growing well: in a month and a half, while the father is traveling, he “recovers” by several kilograms.

Here, again, it's all about "milk": not only did the penguin feed the penguin with fish, but also with this very "bird's milk".

The penguin will return, having eaten in the sea on fish and squid, will again take the cub, and then the penguin will wander through the snow in search of prey.

Sitting for forty-fifty days either with dad or mom on the legs, the young penguin grows up. In the "pocket" he is now cramped. And then he goes to the "kindergarten": in some place, young penguins gather in a bunch. Hundreds of them stand in a dark crowd, clinging to each other, and brother warms brother.

"Kindergarten" run by old birds. When a blizzard spins snow whirlwinds, they surround the chicks from all sides, creating, as zoologists say, a protective rampart.

Parents take turns attending the “kindergarten”; the chicks scream, everyone asks for food, but the penguins in the cry and noise recognize the voices of their penguins and feed only them. Those are unusually gluttonous: they can eat six kilograms of fish at once.

Five-month-old penguins no longer need parents. Spring came, followed by summer, the ice floes melted, began to break off, and on them young graduates of "kindergartens" float to practice at sea. There they learn to dive and fish, and in the meantime they grow feathers.

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If you find a chick, the first thing you need to do is determine its species. Feeding granivorous, insectivorous and predatory chicks have their own differences. But in the early stages of feeding, you can use the same feeding methods, and then, after finding out what kind of bird you found, transfer the chick to the appropriate feeding.

Here is one of the most common feeding options for granivorous and insectivorous chicks. This nutrient mixture is well used for feeding for chicks and fledglings from the passerine family. To prepare our mixture, we need the following products: Boiled egg, low-fat cottage cheese, raw carrots, meat (beef, chicken, turkey), greens (lettuce, dandelion leaves, wood lice), hamarus and daphnia, Calcium gluconate (shell from boiled eggs) glycerophosphate , children's dry dairy-free porridge or boiled millet (without salt and fat on the water).

Action one. Boil the egg, free from the shell. We free the shell from the shell film. Grind the egg as much as possible, you can use a grater with small holes.

Second step. Boiled meat, it is better to take the pulp from the breast of a turkey or chicken and also chop or divide into fibers. The mixture will require meat 40 (for granivorous) and 60 grams (for insectivorous).

Third step. Take washed carrots of a small size, grate them on a fine grater, then squeeze the juice and we will use the remaining pulp.

Fourth step. We take not sour and not fatty cottage cheese. Cottage cheese should have 0% fat content, anything above is considered fat for poultry. We need 90-110 grams of cottage cheese. Sour cottage cheese must be boiled twice changing the water and then it will be suitable.

Step five. You can use greens to add the mixture, but you can do without it for the chicks. And so you can take the greens listed above, chop and add 1.5 teaspoons to the mixture.

Action six. To the above ingredients, add 1.5 -2 tsp. dairy-free porridge or boiled millet (well boiled, without salt and fat in the water).

Step seven. To the mixture we add the shell from the boiled egg, which must first be ground in a coffee grinder, plus one fourth of the crushed tablet of glycerophosphate. If it is not possible to find glycerophosphate, then you can purchase bone meal and add one fourth tsp. in powder form. At the very least, the shells are enough for now.

Step eight. We take chopped hamarus and daphnia and add about 1 tsp to the resulting mixture. Then we mix everything, it turns out a very thick, crumbly porridge, it should not stick to the fingers. If the mixture is sticky, you can add dairy-free porridge or powdered cereals.

From the resulting mixture we roll small balls no larger than a small pea, focus on the size of the chick's beak. You can feed 2-5 balls at a time and after each feeding drink plain water from an insulin syringe with a removable needle (without a needle) 4-6 drops.

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