← Back to the archive★ Support my pages
DD-137NatureFiled Last updated

River Roamers

Short answer: Hippopotamuses (Hippopotamus amphibius) secrete a red-to-orange fluid sometimes called 'blood sweat'. It's neither: it contains pigments, hipposudoric and norhipposudoric acid, that absorb UV light and may inhibit bacteria.

Hippos spend the day in water but can't actually swim or float well; they walk or bounce along the bottom and can stay submerged for around five minutes. On land they can run in short bursts at about 30 km/h. They are among the most dangerous large animals in Africa. The footage shows hippos in rivers and on land, with the presenter.

VideoWrite-up1 sources
More like this★ Support my pagesCite this file

What should you know about River Roamers?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Hippos secrete a red fluid called 'blood sweat'.

    DD-137-F01 · Write-up · Exhibit A (Red secretion)

  2. Its pigments absorb UV light.

    DD-137-F02 · Write-up · Exhibit B (Sunscreen)

Video transcript: River Roamers: Hippos Make Their Own Sunscreen

Hippos secrete a reddish oily substance often referred to as blood sweat, although it's neither blood nor sweat. DID YOU KNOW? This secretion acts as a moisturizer and sunblock, helping to keep the skin hydrated and protected from the harsh rays. Hippos are deceptively agile in water, despite their large size. They are known to be excellent swimmers and can hold their breath for several minutes. Despite their hefty appearance, hippos can move surprisingly fast, both in the water and on land, making them one of the most formidable and unpredictable animals in their habitats. NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 30.4s Reel ·

Video coming soonRiver Roamers · Instagram Reel
River Roamers: Hippos Make Their Own Sunscreen Instagram Reel · · 30.4s

The write-up

Hippos make their own sunscreen. Their red 'blood sweat' is neither blood nor sweat.

  1. Exhibit A

    Red secretion

    Hippos secrete a red fluid called 'blood sweat'.

  2. Exhibit B

    Sunscreen

    Its pigments absorb UV light.

  3. Exhibit C

    Not swimmers

    Hippos walk or bounce along the bottom.

  4. Exhibit D

    Holding breath

    They can stay submerged about five minutes.

  5. Exhibit E

    Fast on land

    They can run about 30 km/h in bursts.

Questions people ask about River Roamers

What is hippo 'blood sweat'?

Neither blood nor sweat.

Source: Write-up · Exhibit A (Red secretion) · Wikipedia: Hippopotamus

What does it help with?

A natural sunscreen.

Source: Write-up · Exhibit B (Sunscreen) · Wikipedia: Hippopotamus

How do hippos move underwater?

They can't really swim.

Source: Write-up · Exhibit C (Not swimmers) · Wikipedia: Hippopotamus

How long can they stay under?

Then surface to breathe.

Source: Write-up · Exhibit D (Holding breath) · Wikipedia: Hippopotamus

How fast can they run on land?

In short bursts.

Source: Write-up · Exhibit E (Fast on land) · Wikipedia: Hippopotamus

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What is hippo 'blood sweat'?

    1. A pigmented secretion
    2. Real blood
    3. Real sweat
    4. Mud
    Show the answer

    Answer: A. A pigmented secretion Neither blood nor sweat. Source: Write-up · Exhibit A (Red secretion) · Wikipedia: Hippopotamus

  2. What does it help with?

    1. Blocking UV light
    2. Flying
    3. Digging
    4. Hearing
    Show the answer

    Answer: A. Blocking UV light A natural sunscreen. Source: Write-up · Exhibit B (Sunscreen) · Wikipedia: Hippopotamus

  3. How do hippos move underwater?

    1. Walking or bouncing on the bottom
    2. Swimming fast
    3. Floating
    4. Flying
    Show the answer

    Answer: A. Walking or bouncing on the bottom They can't really swim. Source: Write-up · Exhibit C (Not swimmers) · Wikipedia: Hippopotamus

  4. How long can they stay under?

    1. About five minutes
    2. An hour
    3. Ten seconds
    4. A day
    Show the answer

    Answer: A. About five minutes Then surface to breathe. Source: Write-up · Exhibit D (Holding breath) · Wikipedia: Hippopotamus

  5. How fast can they run on land?

    1. About 30 km/h
    2. About 3 km/h
    3. About 100 km/h
    4. They can't
    Show the answer

    Answer: A. About 30 km/h In short bursts. Source: Write-up · Exhibit E (Fast on land) · Wikipedia: Hippopotamus

Cite this case file

Easterling, Marcus. "River Roamers." The Detail Department (DetailEnjoyer), case file DD-137, last updated Dec 23, 2023. https://detailenjoyer.com/case/river-roamers/

Permalink: https://detailenjoyer.com/case/river-roamers/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-137-F01 → https://detailenjoyer.com/case/river-roamers/#DD-137-F01