---
title: "What the sources say about the Koala | AnimalTracks.wiki"
description: "60 claims from the Koala profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/koala-1.webp"
canonical: "https://animaltracks.wiki/animals/koala/sources/"
---

# What the sources say about the Koala (*Phascolarctos cinereus*)

> 60 claims from the Koala profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Koala](https://animaltracks.wiki/animals/koala/)

## Phascolarctos cinereus (koala). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Phascolarctos_cinereus/

| The page says | The source says |
| :--- | :--- |
| has built its lifestyle around a bad diet | Because of their low quality diet, koalas conserve energy by their behavior. |
| Average weights run from 5.1 kilograms for northern females to 11.8 kilograms for southern males | Average weights are: in the south, males--11.8 kg, females--7.9 kg; in the north, males--6.5 kg, females 5.1 kg (note: ADW's 'Range mass 5.1 to 11.8 kg' is the span of these population averages, not a range for individual adults, so the page now says averages.) |
| males running up to 50% heavier than females | Males are up to 50% heavier than females |
| In the south of their range, where koalas are generally larger, males average 78 centimeters in head-body length to females' 72 | Koalas from the southern end of the range are generally larger in size than their northern counterparts. ... In the south, males have an average head-body length of 78 cm and females 72 cm |
| an adult can eat 500 grams of leaves a day | An adult koala can eat 500g daily. |
| The trick is a supersized gut | the koala's caecum is up to four times its body size |
| the bacteria inside it | the animals get around this by having a flora of bacteria in their stomachs that metabolize the toxins of the leaves |
| A koala's caecum is huge | the koala's caecum is up to four times its body size (note: The figure is cut: an organ four times the size of the body it sits in is impossible as written, ADW gives no unit (it probably means body length), and no cached source gives a caecum length. The quote backs 'huge' on any reading.) |
| Koalas live in eucalyptus forests below 600 meters in elevation | The koala is confined to eucalyptus forests below 600 m. |
| spread from northern Queensland to southwestern Victoria in eastern Australia | The koalas live in eastern Australia and range from northern Queensland to southwestern Victoria. (note: backs both the body sentence and stats.habitat, which ends with the same clause.) |
| Koalas cool off by licking their arms and stretching out while they rest | The koala cools itself by licking its arms and stretching out as it rests in the trees (note: ADW's '(koalas have no sweat glands)' is cut: an absolute resting only on a 1999 page, and no current source in the cache states it.) |
| Koalas were hunted hard for their fur | In the early 20th century the koala was hunted extensively for its warm, thick coat. |
| Public outcry won them legal protection after 1927 | After1927 as a result of public outcry the koala became legally protected. (note: 'After1927' is copied exactly as the ADW page prints it (missing space).) |
| Eucalyptus forests below 600 meters | The koala is confined to eucalyptus forests below 600 m. |
| an adult can eat 500 grams a day | An adult koala can eat 500g daily. |
| A huge caecum | the koala's caecum is up to four times its body size (note: figure cut, as in the body: see the 'A koala's caecum is huge' claim.) |
| gut bacteria that break down the eucalyptus toxins | the animals get around this by having a flora of bacteria in their stomachs that metabolize the toxins of the leaves |
| leans on gut bacteria | the animals get around this by having a flora of bacteria in their stomachs that metabolize the toxins of the leaves |

## Koala. San Diego Zoo Wildlife Alliance.

https://animals.sandiegozoo.org/animals/koala

| The page says | The source says |
| :--- | :--- |
| Eucalyptus leaves are tough and low in calories | Koalas grind the tough eucalypt leaves with their cheek teeth. They don't get many calories from their diet |
| so koalas save energy by moving only occasionally | They don't get many calories from their diet, but they conserve energy by moving occasionally (note: the 'so' is ADW's causal link too: 'Because of their low quality diet, koalas conserve energy by their behavior.') |
| sleeping 18 to 22 hours a day | koalas sleep 18 to 22 hours a day (note: ADW says 'sleep up to 18 hours a day' and SDZWA's diet section says 'as much as 20 hours'; the page follows SDZWA's own figure, 18 to 22.) |
| Koalas usually live 10 to 15 years | LIFE SPAN Usually 10 to 15 years (note: Replaces ADW's 1999 'may live past 10 years in the wild ... over 20 years in captivity': a duration needs a current source (docs/fact-check.md, 'Check the date').) |
| that most herbivores can't tolerate | Most herbivores can't tolerate eucalypts because of these compounds |
| koalas prefer about three dozen of the more than 600 kinds of eucalypt | there are more than 600 different kinds of eucalypt trees ... Koalas prefer the leaves of about three dozen varieties. (note: ADW gives older, different figures ('eat only 20 of the 350 species of eucalyptus and prefer only 5 species'); the page follows SDZWA.) |
| Two opposable thumbs on each hand and sharp claws give them their grip | Their hands have two opposing thumbs to increase their grip (we only have one), and sharp claws to dig into bark. |
| strong arm and shoulder muscles help them climb up to 46 meters to the top of a tree | Strong arm and shoulder muscles help a koala climb 150 feet (46 meters) to the top of a tree |
| eight million were killed between 1919 and 1924 alone | from 1919 to 1924, eight million koalas were killed |
| dog attacks | Today, the koala is threatened by predation from domestic dogs |
| cars that hit some of them | some koalas get run over by cars |
| disappearing habitat | the loss of their habitat |
| preferring about three dozen of the more than 600 kinds of eucalypt | there are more than 600 different kinds of eucalypt trees ... Koalas prefer the leaves of about three dozen varieties. |
| eucalyptus toxins most herbivores can't tolerate | Most herbivores can't tolerate eucalypts because of these compounds |
| sleeps up to 22 hours a day | koalas sleep 18 to 22 hours a day |
| eucalyptus leaves most herbivores can't tolerate | Most herbivores can't tolerate eucalypts because of these compounds |
| Eucalyptus leaves don't give koalas many calories | They don't get many calories from their diet |
| so they save energy by moving only occasionally | They don't get many calories from their diet, but they conserve energy by moving occasionally |
| Koalas sleep 18 to 22 hours a day | koalas sleep 18 to 22 hours a day |
| about the size of a large jelly bean | it is only about the size of a large jelly bean |
| weighs 0.4 to 1 gram | Weight at birth: .015 to .035 ounces (.4 to 1 gram) (note: SDZWA prints '.4', which is 0.4. FAQ 3 cites SDZWA, which gives 0.4 to 1 gram; the old 'less than 0.5 grams' was ADW's figure, not the FAQ's ref.) |
| It's born blind and deaf | a newborn joey can't even see or hear |
| use its strong forelimbs and hands to crawl from the birth canal into its mother's pouch | it uses strong forelimbs and hands to crawl from the birth canal into its mother's pouch |
| it attaches to a nipple and grows for the next six months | The joey attaches to one of two nipples in this warm, safe place where it drinks milk and grows during the next six months. |
| Once it's too big for the pouch, it rides on her back | After it grows too large for the pouch, the joey climbs onto its mother's back and holds on with strong hands and feet. |

## Woinarski & Burbidge (2020). Phascolarctos cinereus. The IUCN Red List of Threatened Species 2020: e.T16892A166496779.

https://doi.org/10.2305/iucn.uk.2020-1.rlts.t16892a166496779.en

| The page says | The source says |
| :--- | :--- |
| The IUCN now lists the species as Vulnerable | Vulnerable (VU) (note: Cites the Red List's amended 2020 version of the 2014 assessment, which the Red List now shows, in place of the 2016 printing.) |
| Vulnerable | Vulnerable (VU) |

## Charlton et al. (2013). Koalas use a novel vocal organ to produce unusually low-pitched mating calls. Current Biology.

https://doi.org/10.1016/j.cub.2013.10.069

| The page says | The source says |
| :--- | :--- |
| the register of a male koala's mating bellow | During the breeding season, male koalas produce 'bellow' vocalisations that are characterised by a continuous series of inhalation and exhalation sections, and an extremely low fundamental frequency (note: vibe.reason. San Diego Zoo's 'Endangered' banner is Australia's national listing; the Red List category is Vulnerable.) |
| a novel vocal organ drops each inhalation to an average 27.1 Hz, 20 times lower than expected for an 8 kg animal | the fundamental frequency (F0) of bellow inhalation sections averages 27.1 Hz (range: 9.8-61.5 Hz [1]), which is 20 times lower than would be expected for an animal weighing 8 kg [2] ... koalas use a novel vocal organ to produce their unusually low-pitched mating calls (note: vibe.reason. Abstract only on disk; every figure is in the abstract.) |

## Dahlhausen et al. (2020). Isolation and sequence-based characterization of a koala symbiont: Lonepinella koalarum. PeerJ.

https://doi.org/10.7717/peerj.10177

| The page says | The source says |
| :--- | :--- |
| Eucalyptus leaves carry chemical defenses, including tannins, phenolic compounds and terpenes | All Eucalyptus species contain chemical defenses against herbivory that include tannins, B-ring flavanones, phenolic compounds, terpenes, formylated phloroglucinols, cyanogenic glucosides and other plant secondary metabolites |
| Koalas manage on almost nothing else | feed almost exclusively on the foliage of select Eucalyptus species |
| one of the bacteria living in the mucus around it is Lonepinella koalarum | One of these cultured isolates is a bacterium known as Lonepinella koalarum ... It had been first isolated from the mucus around the caecum in koalas |
| A Tannin-Busting Bacterium | was shown to degrade tannin-protein complexes that can be found in Eucalyptus leaves (note: The blockquote's lead-in, which replaced 'Eats Poison for a Living': the paper found no direct evidence for tannase genes in its strain.) |
| Lonepinella koalarum was first isolated from the mucus around a koala's caecum, and it has been shown to break down the tannin-protein complexes in eucalyptus leaves | It had been first isolated from the mucus around the caecum in koalas and was shown to degrade tannin-protein complexes that can be found in Eucalyptus leaves |
| complexes that koalas cannot digest | cannot be digested by koalas or utilized by microbes (note: backs both the body blockquote and FAQ 1's closing sentence; source: 'Tannins bind proteins followed by the formation of a precipitate, which cannot be digested by koalas or utilized by microbes.') |
| chlamydia, a common infection | high prevalence of Chlamydia infections |
| Almost exclusively eucalyptus leaves | feed almost exclusively on the foliage of select Eucalyptus species |
| Every eucalyptus species contains chemical defenses against plant-eaters, including tannins, phenolic compounds and terpenes | All Eucalyptus species contain chemical defenses against herbivory that include tannins, B-ring flavanones, phenolic compounds, terpenes, formylated phloroglucinols, cyanogenic glucosides and other plant secondary metabolites |
| Koalas carry gut bacteria that have been studied for breaking those defenses down | several bacterial isolates associated with the intestinal microbial communities of koalas have been characterized in the context of degradation of PCDs found in Eucalyptus leaves (note: PCDs are the paper's plant chemical defenses, the compounds named in the previous sentence.) |
| Lonepinella koalarum, first isolated from the mucus around a koala's caecum | It had been first isolated from the mucus around the caecum in koalas |
| has been shown to break down the tannin-protein complexes in eucalyptus leaves | was shown to degrade tannin-protein complexes that can be found in Eucalyptus leaves |

## Waugh et al. (2017). Infection with koala retrovirus subgroup B (KoRV-B), but not KoRV-A, is associated with chlamydial disease in free-ranging koalas (Phascolarctos cinereus). Scientific Reports.

https://doi.org/10.1038/s41598-017-00137-4

| The page says | The source says |
| :--- | :--- |
| whose primary culprit, Chlamydia pecorum, causes eye infections, reproductive disease and even death | Koalas are infected with two species of Chlamydia , C. pecorum and C. pneumoniae ... with C. pecorum being the primary pathogen, causing keratoconjunctivitis, reproductive disease, and even death (note: keratoconjunctivitis is inflammation of the cornea and conjunctiva, here caused by the infection: 'eye infections' for a teen reader.) |