Tagged “animal facts”

1. Animals urinate in the same amount of time...

   March 2026

   I learned that (almost) all mammals take the same amount of time to urinate from a book of facts.

   All mammals that weigh more than about six-and-a-half pounds take about the same time to urinate, thanks to the structure of the urethra. Karen Hopkin reports

   — Scientific American

   But today I learned that mammals also defecate in the same amount of time!

   What else did we learn? Bigger animals have longer feces. And bigger animals also defecate at higher speed. For instance, an elephant defecates at a speed of six centimeters per second, nearly six times as fast as a dog. The speed of defecation for humans is in between: two centimeters per second.

   Together, this meant that defecation duration is constant across many animal species – around 12 seconds (plus or minus 7 seconds) – even though the volume varies greatly. Assuming a bell curve distribution, 66 percent of animals take between 5 and 19 seconds to defecate. It's a surprisingly small range, given that elephant feces have a volume of 20 liters, nearly a thousand times more than a dog's, at 10 milliliters. How can big animals defecate at such high speed?

   ...

   Putting the length of feces together with the properties of mucus, we now have a cohesive physics story for how defecation happens. Bigger animals have longer feces, but also thicker mucus, enabling them to achieve high speeds with the same pressure. Without this mucus layer, defecation might not be possible. Alterations in mucus can contribute to several ailments, including chronic constipation and even infections by bacteria such as C. difficile in the gastrointestinal tract.

   Beyond simply following our scientific curiosity, our measurements of feces have also had some practical applications. Our defecation data helped us design an adult diaper for astronauts. Astronauts want to stay in space suits for seven days, but are limited by their diapers. Taking advantage of the viscosity of feces, we designed a diaper that segregates the feces away from direct contact with skin. It was a semifinalist in the NASA Space Poop Challenge earlier this year.

   PBS

2. Arctic Ground Squirrels

   March 2026

   

   Arctic Ground Squirrels hibernate for something like eight months of the year—and when they are hibernating, their body temperature goes down to freezing (or even slightly below!) and they let their brains die. Then, over a couple hours when they emerge from hibernation, they regrow their brains. And, they indeed don't have the same memories they had before—they don't fear theings they feared the year before. But, don't worry, they do remember their friends.

   Listen to this great Radiolab Terrestrials episode to learn more.

   The photo is by Joel Sartore. Here's what he posted about the squirrels:

   Hibernating Arctic ground squirrels (Spermopilus parryii) at the University of Alaska at Fairbanks. This animal is the grand champion of all hibernators. It’s the only mammal that can drop its body temperature to below freezing. They hibernate for seven months. Females go in first, in August. Males follow a month later. They come out again to feed on tundra plants in May. Biologists at UAF have been studying the animal for 20 years, but still can’t figure out how this animal maintains a flat body temperature for all those months just above freezing. “You could put people into hibernation for space trips if you could understand it better,” said Franziska ‘Fran’ Kohl, one of the biologists here. “They also show symptoms of Alzheimers during hibernation.” She added that traumatic head injuries heal when in hibernation, another thing scientists are trying to figure out.

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