---
title: "What the sources say about the Red Squirrel | AnimalTracks.wiki"
description: "43 claims from the Red Squirrel profile, each beside the words of the source that backs it."
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---

# What the sources say about the Red Squirrel (*Sciurus vulgaris*)

> 43 claims from the Red Squirrel profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Red Squirrel](https://animaltracks.wiki/animals/red-squirrel/)

## Sciurus vulgaris (Eurasian red squirrel). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Sciurus_vulgaris/

| The page says | The source says |
| :--- | :--- |
| Coat colour varies more in this species than in almost any other Palearctic mammal, running from light red to black | This species has more variation in coat color than almost any other mammal in the Palearctic region ... The color of these squirrels varies from light-red to black on their heads and backs. |
| in some places a whole population shares one colour: in Britain only red-coated animals live, and in the Sila region of southern Italy only black ones | in some areas, whole populations may have almost identically colored coats. Examples of populations in which all of the squirrels share the same coat color can be found in Great Britain, where only red members of this species live; and in the Sila region of southern Italy, where only black individuals are found |
| a specialised way of opening a nut, using the power of its lower incisors, and with practice can crack one in just a few seconds | They have a specialized technique for opening nuts that utilizes the power of the lower incisors. With practice they are able to open a nut in just a few seconds. |
| eats the most in spring, about 80g a day, and the least in winter, about 35g a day | They eat the most food in the spring (80g per day), and the least in the winter (35g per day). |
| It buries food in the ground or hides it in tree bark | this species stores food supplies by burying them in the ground or hiding them in the bark of trees |
| forgotten caches may sprout into new trees | Forgotten caches may end up sprouting and growing into new trees. |
| It always keeps several nests, which it can escape to when a predator gives chase. A high-quality nest may be used for several years. | A high quality nest may be used for several years, and individuals always maintain several nests to which they can escape when being pursued by a predator. |
| Its body hair changes twice a year, and the winter coat is thicker, has longer ear tufts and covers more of the soles of the feet than the spring and summer coat. The tail hair changes only once a year. | The body hair of these squirrels changes twice annually, while the tail hair changes only once. The winter coat covers more of the soles of the feet, has longer ear tufts, and is thicker than the spring/summer coat. |
| tree bark and sap | observed peeling the bark off conifers and licking the trees' sap |
| The red squirrel lives throughout the forests of Europe and northern Asia. | can be found throughout the forests of Europe and northern Asia |
| a North American species | In Great Britain, the introduction of a North American species of tree squirrel, the eastern gray squirrel ( Sciurus carolinensis ), has led to the disappearance of native Eurasian red squirrels throughout much of the country |
| Double-jointed canopy acrobat that cracks a nut in seconds and buries seeds that may grow into trees. | With practice they are able to open a nut in just a few seconds ... Forgotten caches may end up sprouting and growing into new trees. (note: tagline; double-jointed ankles from woodland-trust-red-squirrel (claim for the superpower)) |
| using the power of its lower incisors, it can open a nut in just a few seconds | They have a specialized technique for opening nuts that utilizes the power of the lower incisors. With practice they are able to open a nut in just a few seconds. (note: vibe.reason, settled in #836.) |

## Red squirrel (Sciurus vulgaris). Woodland Trust.

https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/red-squirrel/

| The page says | The source says |
| :--- | :--- |
| weighs around 300g against a grey squirrel's roughly 540g | weighing around 540g, compared to just 300g for red squirrels |
| its body runs under 25cm long | a body length of less than 25cm |
| with a bushy tail almost as long again | Red squirrels have a large bushy tail that is almost as long as their body. |
| In Britain pine seeds are a particular favourite, along with hazelnuts and the seeds of larch and spruce, plus fruit, tree shoots, bark, lichen and fungi | Pine seeds are a particular favourite, but they will also take hazelnuts, and the seeds of larch and spruce. Also eaten are fruit, tree shoots, bark, lichen and fungi. |
| A red squirrel can jump more than two metres | Red squirrels can jump more than 2m |
| double-jointed ankles let it move up and down trees with ease | Double-jointed ankles mean red squirrels can move up and down trees with ease. |
| Its nests, called dreys, sit high in the trees, built from twigs and lined with moss and leaves | Dreys are located high up in trees and made from twigs and lined with moss, leaves and other soft materials. |
| In Britain the grey squirrel, a North American species introduced in the early 20th century | This is largely due to the introduction of non-native grey squirrels in the early 20th century. |
| is an immune carrier of the squirrelpox virus, which is fatal to reds | they also carry the squirrelpox virus, which they are immune to, but which is fatal to reds |
| Largely because of the greys, which also outcompete them, reds have now disappeared from most of England and Wales | This is largely due to the introduction of non-native grey squirrels in the early 20th century. The larger greys can outcompete reds and they also carry the squirrelpox virus, which they are immune to, but which is fatal to reds. Reds have now disappeared from most of England and Wales. |
| An estimated 287,000 remain in Britain against 2.7 million greys | There are an estimated 287,000 red squirrels in Britain, compared to 2.7 million greys. |
| confined to Scotland, pockets of northern England and Wales, and small islands off England's south coast | Now red squirrels are confined to Scotland, pockets of northern England and Wales and small islands off England's south coast. |
| They are still found across much of Ireland, though the range is shrinking there too | The species can still be found across much of Ireland, but its range is shrinking there too. |
| In Britain, foxes, stoats, pine martens and birds of prey hunt them as well. | Predators: pine marten, birds of prey, foxes and stoats. |
| Grey squirrels carry the squirrelpox virus and are immune to it. Red squirrels are not, and the virus is fatal to them. | they also carry the squirrelpox virus, which they are immune to, but which is fatal to reds |
| Double-jointed ankles for moving up and down trees with ease, plus a jump of more than two metres. | Double-jointed ankles mean red squirrels can move up and down trees with ease ... Red squirrels can jump more than 2m (note: combines the two Woodland Trust facts already used as body claims; superpower field) |
| Coniferous, broadleaved and mixed woodland across Europe and northern Asia, with UK strongholds in Scotland, pockets of northern England and Wales, and small islands off England's south coast | Now red squirrels are confined to Scotland, pockets of northern England and Wales and small islands off England's south coast. (note: stats.habitat; wider Europe/northern Asia range from adw-sciurus-vulgaris ("can be found throughout the forests of Europe and northern Asia")) |
| Pine and conifer seeds, hazelnuts, fruit, fungi, tree bark and sap, and tree shoots | Pine seeds are a particular favourite, but they will also take hazelnuts, and the seeds of larch and spruce. Also eaten are fruit, tree shoots, bark, lichen and fungi. (note: stats.diet; sap from adw-sciurus-vulgaris) |

## Sciurus vulgaris (Eurasian red squirrel). AnAge: The Animal Ageing and Longevity Database, Build 15.

https://genomics.senescence.info/species/entry.php?species=Sciurus_vulgaris

| The page says | The source says |
| :--- | :--- |
| Wild red squirrels may live up to 12 years | In the wild, these animals may live up to 12 years |
| one in captivity lived over 14.8 years | Maximum longevity 14.8 years (captivity) ... One specimen lived over 14.8 years in captivity. |

## Gazzard (2024). Sciurus vulgaris. The IUCN Red List of Threatened Species 2024: e.T221730864A221731815.

https://doi.org/10.2305/iucn.uk.2024-2.rlts.t221730864a221731815.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN Red List category: Least Concern (LC). (note: checked via GBIF's copy of the Red List for IUCN taxon 221730864, Sciurus vulgaris; iucnredlist.org itself refuses scripts) |

## Avanzi et al. (2016). Red squirrels in the British Isles are infected with leprosy bacilli. Science.

https://doi.org/10.1126/science.aah3783

| The page says | The source says |
| :--- | :--- |
| Researchers found leprosy bacteria in squirrels from England, Ireland and Scotland, some with leprosy-like lesions on the head and limbs, others seemingly healthy | Red squirrels in Great Britain (Sciurus vulgaris) have increasingly been observed with leprosy-like lesions on the head and limbs. Using genomics, histopathology, and serology, we found M. lepromatosis in squirrels from England, Ireland, and Scotland, and M. leprae in squirrels from Brownsea Island, England. Infection was detected in overtly diseased and seemingly healthy animals. |
| The strain from Brownsea Island is closest to one that circulated in medieval England | M. leprae in squirrels from Brownsea Island, England ... the M. leprae strain is closest to one that circulated in Medieval England |
| Red squirrels are a reservoir for leprosy in the British Isles. | Red squirrels are thus a reservoir for leprosy in the British Isles. |

## Ploemacher et al. (2020). Reservoirs and transmission routes of leprosy; A systematic review. PLOS Neglected Tropical Diseases.

https://doi.org/10.1371/journal.pntd.0008276

| The page says | The source says |
| :--- | :--- |
| Leprosy was considered a disease of humans, with the exception of the armadillo, so finding it in red squirrels in 2016 was highly unexpected | In 2016, both M . leprae and M . lepromatosis DNA was found in red squirrels ( Sciurus vulgaris) with leprosy-like lesions in the British Isles.[ 23 ] This was highly unexpected, primarily because leprosy was considered to be a disease of humans (with the exception of the armadillo) |
| An Unexpected Reservoir | This was highly unexpected, primarily because leprosy was considered to be a disease of humans (with the exception of the armadillo) (note: blockquote lead; 'reservoir' from avanzi-2016) |

## Sainsbury et al. (2008). Poxviral Disease in Red Squirrels Sciurus vulgaris in the UK: Spatial and Temporal Trends of an Emerging Threat. EcoHealth.

https://doi.org/10.1007/s10393-008-0191-z

| The page says | The source says |
| :--- | :--- |
| A study of red squirrels found dead between 1993 and 2005 | used pathological signs and transmission electron microscopy (TEM) to diagnose SQPV disease in red squirrels found dead during scanning surveillance between 1993 and 2005 |
| found the disease only in areas of England also inhabited by grey squirrels, supporting a role for the grey as a reservoir host of the virus | SQPV disease occurred only in areas of England also inhabited by seropositive gray squirrels, and as the geographical range of gray squirrels expanded, SQPV disease occurred in these new gray squirrel habitats, supporting a role for the gray squirrel as a reservoir host of the virus. |
| There was a delay between greys settling an area and disease showing up in reds, implying the greys must reach a threshold number or density before passing the virus on | There was a delay between the establishment of invading gray squirrels and cases of the disease in red squirrels which implies gray squirrels must reach a threshold number or density before the virus is transmitted to red squirrels. |

## Schmidt & Fischer (2011). The kinematic consequences of locomotion on sloped arboreal substrates in a generalized (Rattus norvegicus) and a specialized (Sciurus vulgaris) rodent. Journal of Experimental Biology.

https://doi.org/10.1242/jeb.051086

| The page says | The source says |
| :--- | :--- |
| On an inclined branch it flexes and retracts its limbs to bring its centre of mass close to the branch, placing its forelimbs to the side and underneath while its hindlimbs stay roughly on top | Rats and European red squirrels increased limb flexion and retraction in order to bring the center of mass as close as possible to the substrate surface and to achieve maximum propulsion. Additionally, forelimbs were placed more laterally and underneath the branch whereas the hindlimbs were placed approximately on the top of the branch. (note: study examined 30 and 60 degree inclined branches) |