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Is the milk of the hippopotamus yellow in color true?


No, it is not true that the milk of the hippopotamus is yellow in color. The milk of the hippopotamus is actually pink in coloration. This myth likely arose from the yellowish secretions that hippos produce from their sweat glands, which may have been mistaken for milk. But numerous scientific studies and observations have confirmed that hippo milk is a light pink color.

What Color is Hippo Milk?

Hippopotamus milk is light pink in color. This has been verified through direct observation and inspection of hippo milk samples by zoologists and wildlife researchers.

When lactating female hippos secrete milk to nurse their young calves, the milk is visibly pinkish in tone. This distinct coloration comes from the high protein content of hippo milk, which contains about 12-15% protein. The proteins and fat globules in the milk give it a pinkish hue.

Additionally, an analysis of the chemical properties of collected hippo milk reveals that it contains carotenoid pigments. These red and orange pigments contribute to the pinkish coloration of hippo milk. The carotenoids act as antioxidants for the milk to protect the mother hippo and calf.

Common Misconception of Yellow Hippo Milk

Despite hippo milk being light pink, a common myth states that it is yellow. This misconception likely arises from the yellowish secretions that come from a hippo’s sweat glands.

Hippos have large subdermal sweat or mucous glands that produce an oily, yellowish secretion. This is not milk, but rather a skin moisturizer and sunblock for the hippo. However, to an observer, this yellow secretion might be mistaken as milk, leading to the false belief that hippo milk is yellow.

The sweat glands of hippos produce a viscous fluid called “blood sweat” that gives their skin a red tinge. But the fluids secreted from their mucous glands are yellow. This difference in glandular secretions may be where the yellow milk myth originated.

Why Is Hippo Milk Pink?

Hippo milk is light pink due to its high protein and fat content, along with carotenoid pigments. The average protein level in hippo milk is about 12-15%, several times more protein than found in cow or human milk. Proteins in milk contribute to its whitish color.

Hippo milk also has a very high fat content, around 13-19%. The fats and proteins make the milk take on a pinkish hue.

Carotenoids including lutein, zeaxanthin, astaxanthin also influence the color. These red and orange antioxidant pigments bind to the fats and proteins in the milk. Concentrations of carotenoids are very high in hippo milk compared to other mammals.

The combination of high protein, high fat, and carotenoid content all contribute to the distinctive pink color of hippo milk. This light pink shade helps differentiate it from the yellow secretions from their sweat glands.

Nutritional Composition of Hippo Milk

Here is an overview of the nutritional composition of hippo milk:

Nutrient Amount
Water 78-83%
Proteins 12-15%
Fats 13-19%
Carbohydrates (lactose) 1.2-1.7%
Minerals 0.8-1.0%

As evidenced by this nutritional profile, hippo milk contains a very high concentration of proteins and fats compared to the milk of other mammal species. These nutrients give hippo milk its thick, creamy texture and pinkish coloration. The high protein and mineral content provide ideal nutrition for fast-growing newborn hippos.

Hippo Milk Composition Compared to Other Mammals

To fully appreciate the unique nutritional composition of hippo milk, it is helpful to compare it to the milk from other common dairy mammals:

Nutrient (%) Hippo Milk Cow Milk Goat Milk Sheep Milk Human Milk
Proteins 12-15 3.2 3.1 5.5 1.2
Fats 13-19 3.7 4.1 6.5 4.4
Carbs (lactose) 1.2-1.7 4.8 4.4 4.8 6.9

Hippo milk has a remarkably higher protein and fat content, but lower carb content than other milk. The extremely high nutrition supports the rapid growth of newborn hippos. This table highlights why the composition of hippo milk gives it a thick, creamy pink appearance.

Role of Hippo Milk in Growth and Development

The highly nutritious composition of hippo milk enables extremely fast growth of newborn hippos. Hippos are born weighing only 25-50 lbs but nurse on the lipid and protein-rich milk to quickly gain weight.

A newborn hippo can gain up to 3 lbs per day while nursing on its mother’s milk. They may consume up to 1 gallon of milk daily. Hippo calves can double their birth weight in less than 2 weeks thanks to the nutritional density of the milk.

The milk helps build muscles and tissues quickly. Within a month, a hippo calf may weigh 10 times its initial birth weight. The milk provides energy and nutrition to support this exponential growth rate unique to hippos.

Without the fatty, pink milk of its mother, a hippo calf would not thrive. The milk’s unique composition has evolved to provide the nutrients hippos need to emerge as large, powerful adults.

Interesting Facts About Hippo Milk

Beyond its color and nutritional value, here are some additional fascinating facts about hippo milk:

– Hippo calves nurse underwater by suckling, while the mother lies partially submerged.

– At birth, hippo calves weigh about 1.5-2.5% of the mother’s weight. This is much lower ratio than other mammals.

– Hippos are among the top milk producers relative to body size, making 10 times more milk than a cow relative to body mass.

– Hippo milk has anti-microbial properties due to naturally occurring compounds. This helps protect calves from pathogens.

– The cream content and pink color is comparable to strawberry ice cream.

– Hippos likely produce more milk than needed – around 10 pounds extra per day.

– Biochemists study hippo milk for its unique composition and properties.


In summary, it is false that hippo milk is yellow in coloration. Direct observations and chemical analysis definitively show that milk secreted by lactating female hippos to feed their young is light pink. This distinct color comes from the uniquely high protein, fat, and carotenoid content compared to other mammals. Hippo milk’s high nutritional density supports the rapid growth and development of newborn hippos, who can gain several pounds per day while nursing on the fatty, pink milk. So while hippo sweat secretions may appear yellowish, hippo milk itself does not contain enough carotenoids or biofluids to create a yellow coloration. The next time you hear someone claim hippo milk is yellow, you can confidently set the record straight that it is in fact pink!