Every morning the writer will definitely start the day by drinking a glass of very refreshing cow’s milk. If you have a little more sustenance, you can also taste goat’s milk, but the much higher price makes the pleasure of drinking goat’s milk rare.
Apart from the two domestic animals, there are also some animals that produce milk and are used by humans; such as buffalo, sheep, camel, deer and wildebeest. But have you ever heard of milk produced by birds? It must be rare to hear, right?
Do birds really produce milk, you ask? True. There are birds that produce milk but in the whole world so far there are only 3 birds that have been recorded to be able to produce milk. What bird is that? Let’s learn.
Do birds breastfeed?
Although all three birds that we will mention shortly are able to produce milk, the way they nurse their young is also different compared to other mammals. We touch on the method used later!
In scientific studies, the milk produced by birds is called ‘crop milk. We are not sure if the translation is true or not, but a cache is a pouch in the neck of animals such as chickens and birds that can store food.
The cache or ‘crop’ is also the animal organ where the bird’s milk will be produced before being fed to the animals’ children in a unique way. In a study conducted on cache milk, it was found that its content has the same nutrients as the milk of mammalian animals, where it contains anti-oxidants and proteins that help the development of young birds.
The liquid produced in the bird’s neck contains proteins, minerals, antibodies and fats that the young birds need, but for now researchers still do not understand how the milk is produced. Which bird can produce milk?
There are only 3 in the world that have been discovered so far – the first two are pigeons and flamingos.
Pigeons and flamingos
Both types of birds will ‘nurse’ their young with cache milk at an early age when their young are born, usually on the first day after the young birds emerge from the eggshell.
Unlike mammalian milk which comes in a liquid state, the milk cache of these two birds is more viscous – requiring the mother to feed her young using her own beak. This stored milk will be the only main source of food for the baby bird for the first few days.
Both mother doves and flamingos will experience the same lactation process as mammals, a few days before the eggs will hatch. The process will produce milky material that will be stored in the cache, replacing food that is normally stored there.
What is more surprising, in a study of pigeons in 2011 – it was found that both types of pigeons whether male or female are able to perform a similar process of processing their food to be stored for milk production.
Both pigeons and flamingos suckle their young by connecting their beaks, before ‘spitting’ the stored milk into their young’s alimentary canal to allow their young to grow into adults. Unlike pigeons who nurse their young for a week at most, flamingos nurse their young for 2 months.
Emperor Penguin
Among all animal species, male emperor penguins play the most role in raising their young, compared to other animals. This is because the emperor penguin’s lifestyle requires female penguins to leave their home area after laying eggs.
The egg will be incubated by the male emperor penguin to ensure it is warm, placed in the middle of his leg to ensure that the heat is trapped to help the growth of his young. This is interesting about this species – if the egg hatches before the mother returns, the father will play the role of raising the child; including being responsible for breastfeeding.
Just like pigeons and flamingos, the milk that will be produced by male penguins is also categorized in the category of ‘cache milk,’ very rich in protein that is produced from the lining of the esophagus of his father.
After the return of his partner who returned with a belly full of food, the male will stop caring for his child who broke early and went into the sea looking for food for the first time after caring for his child for more than 65 days. Male and female penguins will take turns caring for their hatchlings for over 50 days before being allowed to start living on their own.