“…and today we’re talking about an arboreal ignoramus. But more on that later.”
Way out in the land down under, a famous little gray puff gremlin spends its days as a literal tree-hugger. Like its equally famous black and white counterpart in China, the Panda, the Koala is a threatened cutie that eats terribly, sleeps a lot, and gives its kids a good ol’ fashioned fecal smoothie in order to not die from the poison it eats every day. But as we often tell our kids, sometimes you gotta find a way to eat your leafy greens here in Life, Death, and Taxonomy..
Description of the Koala
Koalas have stout, tailless bodies, round, fluffy ears, and a distinctive, shiny, black spoon-shaped nose.
Its fur color can vary from silver-gray to chocolate brown, but the most iconic coloration is light gray with white bellies.
Koalas in the north (warmer and closer to the equator) are smaller and lighter in color compared to southern ones.
It is possible that these populations are separate subspecies, but there is debate surrounding this claim.
Measure Up
Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We don’t have a new Measure Up intro.
Cultural Critters:
- “Ode to a Koala Bear” by Paul McCartney 0:28
Length
- 60–85 cm (24–33 in)
- How many Koalas go into the length of the confirmed kill by sniper Sergeant Major Herbert Sleigh in February 1918 during the first World War.
- Hint: Sleigh was using the standard issue M1903 Springfield rifle when he made the shot. He served in the American Expeditionary Forces on the Western Front of WWI.
- 1,505 Koalas. The shot was 1,280 meters (1,400 yards) long.
Weight
- 4–15 kg (9–33 lb)
- How many unloaded Beaumont-Adams revolvers go into the weight of a koala?
- Hint: The Beaumont-Adams revolver is a British revolver that was used by the British Army from 1856 to 1880, until it was replaced by the Enfield MK I. However, it was a popular side arm in WWII among the Australian Volunteer Defence Corps. The VDC was initially made up of WWI veterans tasked with home defense and preparing for guerrilla warfare in the case of an invasion.
- 13 revolvers. The Beaumont-Adams revolver is 2.4 lbs (1.1 kg).
Fast Facts About the Koala
Koalas are arboreal creatures that live in Eastern Australia in open woodlands.
Like most marsupials, they are born before they are fully developed. After being born, a baby koala, known as a joey, climbs up to its mother’s pouch. Even though it is blind and deaf, the joey uses its strong sense of touch and smell to navigate its way.
The koala’s brain is only 60% of the typical diprotodont’s, weighing 19.2g on average. That means it has one of the lowest brain to body ratios among mammals. The brain’s surface is fairly smooth, so all the thoughts slide off of it.
The brain only takes up 61% of the cranial cavity, and the rest is filled with fluid. This waterbed head makes the koala concussion resistant, which helps if it were to fall out of a tree.
This little brain is energy efficient. No think, only salads and naps.
Koalas don’t have great eyesight, but they find food by smelling the oils on branches, zeroing in on their coveted tree salads.
If there was a koala choir, they would all be basses. The koala larynx is located low in the vocal tract and they have unique velar vocal folds. These features make their vocal sounds comically lower than you would expect from a creature of their size.
Koalas are asocial animals and spend just 15 minutes a day on social behaviors.
The koala hugs the tree to lose heat without panting. It also has a dark scent gland in the middle of its chest that marks trees as its own when it hugs.
Koalas can carry Chlamydia, a highly infectious bacteria which is theorized to control the populations so forests are not completely stripped of leaves.
- It causes infertility, blindness, and the worst UTI imaginable
- This can be transferred to people if they come into contact with infected koala urine, which is easy when koalas just go when spirit is upon them
- The University of Melbourne says that as many as half of all koalas are infected.
Major Fact: Eucalip-Smacking Good
Though the foliage of over 600 species of Eucalyptus is available, the koala shows a strong preference for around 30. They tend to choose species that have a high protein content and low proportions of fiber and lignin.
Since eucalypt leaves have a high water content, the koala does not need to drink often. Although females can meet their water requirements by eating leaves, larger males require additional water found on the ground or in tree hollows.
Koalas consume over 2 pounds of leaves a day, spread over four to six feeding sessions. The koala’s digestive system is particularly good at tolerating its toxic eucalyptus diet, which, even in small amounts, can often be poisonous and fatal to most animals when ingested since it’s basically cyanide. Special liver enzymes and symbiotic gut bacteria in a specialized organ called a caecum help to break down poisonous compounds, thus allowing koalas to survive on a diet of eucalyptus leaves.
They don’t get this bacteria naturally. Mother koalas excrete a sticky runny faecal substance called “pap” that the baby eats to get the gut fauna it needs to digest eucalyptus.
Their diet makes them actually smell like eucalyptus and gives them a natural insect repellent. However, these leaves are low in fiber and the koala can only absorb 25% of the fiber it ingests, which is why it needs to eat so much.
Despite their adaptations to a low-energy lifestyle, they have low fat reserves and need to eat frequently. Because they get so little energy from their diet, koalas must limit their energy use and sleep or rest 20 hours a day.
Ending: So eat your pap, keep your chlamydia to yourself, and eat your toxic leafy greens like the koala here in LDT.