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What the sources say

Red SquirrelSciurus vulgaris

Every figure, record and mechanism on the Red Squirrel profile was written from a source, and this is the working table behind it: 43 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Animal Diversity Web, University of Michigan

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

The page saysCoat colour varies more in this species than in almost any other Palearctic mammal, running from light red to black
The source saysThis 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.
The page saysin 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
The source saysin 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
The page saysa specialised way of opening a nut, using the power of its lower incisors, and with practice can crack one in just a few seconds
The source saysThey 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.
The page sayseats the most in spring, about 80g a day, and the least in winter, about 35g a day
The source saysThey eat the most food in the spring (80g per day), and the least in the winter (35g per day).
The page saysIt buries food in the ground or hides it in tree bark
The source saysthis species stores food supplies by burying them in the ground or hiding them in the bark of trees
The page saysforgotten caches may sprout into new trees
The source saysForgotten caches may end up sprouting and growing into new trees.
The page saysIt always keeps several nests, which it can escape to when a predator gives chase. A high-quality nest may be used for several years.
The source saysA 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.
The page saysIts 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 source saysThe 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.
The page saystree bark and sap
The source saysobserved peeling the bark off conifers and licking the trees' sap
The page saysThe red squirrel lives throughout the forests of Europe and northern Asia.
The source sayscan be found throughout the forests of Europe and northern Asia
The page saysa North American species
The source saysIn 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
The page saysDouble-jointed canopy acrobat that cracks a nut in seconds and buries seeds that may grow into trees.
The source saysWith 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)
The page saysusing the power of its lower incisors, it can open a nut in just a few seconds
The source saysThey 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.

Source
02

Woodland Trust

Red squirrel (Sciurus vulgaris). Woodland Trust.

The page saysweighs around 300g against a grey squirrel's roughly 540g
The source saysweighing around 540g, compared to just 300g for red squirrels
The page saysits body runs under 25cm long
The source saysa body length of less than 25cm
The page sayswith a bushy tail almost as long again
The source saysRed squirrels have a large bushy tail that is almost as long as their body.
The page saysIn 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
The source saysPine 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.
The page saysA red squirrel can jump more than two metres
The source saysRed squirrels can jump more than 2m
The page saysdouble-jointed ankles let it move up and down trees with ease
The source saysDouble-jointed ankles mean red squirrels can move up and down trees with ease.
The page saysIts nests, called dreys, sit high in the trees, built from twigs and lined with moss and leaves
The source saysDreys are located high up in trees and made from twigs and lined with moss, leaves and other soft materials.
The page saysIn Britain the grey squirrel, a North American species introduced in the early 20th century
The source saysThis is largely due to the introduction of non-native grey squirrels in the early 20th century.
The page saysis an immune carrier of the squirrelpox virus, which is fatal to reds
The source saysthey also carry the squirrelpox virus, which they are immune to, but which is fatal to reds
The page saysLargely because of the greys, which also outcompete them, reds have now disappeared from most of England and Wales
The source saysThis 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.
The page saysAn estimated 287,000 remain in Britain against 2.7 million greys
The source saysThere are an estimated 287,000 red squirrels in Britain, compared to 2.7 million greys.
The page saysconfined to Scotland, pockets of northern England and Wales, and small islands off England's south coast
The source saysNow red squirrels are confined to Scotland, pockets of northern England and Wales and small islands off England's south coast.
The page saysThey are still found across much of Ireland, though the range is shrinking there too
The source saysThe species can still be found across much of Ireland, but its range is shrinking there too.
The page saysIn Britain, foxes, stoats, pine martens and birds of prey hunt them as well.
The source saysPredators: pine marten, birds of prey, foxes and stoats.
The page saysGrey squirrels carry the squirrelpox virus and are immune to it. Red squirrels are not, and the virus is fatal to them.
The source saysthey also carry the squirrelpox virus, which they are immune to, but which is fatal to reds
The page saysDouble-jointed ankles for moving up and down trees with ease, plus a jump of more than two metres.
The source saysDouble-jointed ankles mean red squirrels can move up and down trees with ease ... Red squirrels can jump more than 2mNote: combines the two Woodland Trust facts already used as body claims; superpower field
The page saysConiferous, 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
The source saysNow 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")
The page saysPine and conifer seeds, hazelnuts, fruit, fungi, tree bark and sap, and tree shoots
The source saysPine 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

Source
03

AnAge: The Animal Ageing and Longevity Database, Build 15

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

The page saysWild red squirrels may live up to 12 years
The source saysIn the wild, these animals may live up to 12 years
The page saysone in captivity lived over 14.8 years
The source saysMaximum longevity 14.8 years (captivity) ... One specimen lived over 14.8 years in captivity.

Source
04

Gazzard 2024

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

The page saysLeast Concern
The source saysIUCN 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

Source
05

Avanzi et al. 2016

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

The page saysResearchers found leprosy bacteria in squirrels from England, Ireland and Scotland, some with leprosy-like lesions on the head and limbs, others seemingly healthy
The source saysRed 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 page saysThe strain from Brownsea Island is closest to one that circulated in medieval England
The source saysM. leprae in squirrels from Brownsea Island, England ... the M. leprae strain is closest to one that circulated in Medieval England
The page saysRed squirrels are a reservoir for leprosy in the British Isles.
The source saysRed squirrels are thus a reservoir for leprosy in the British Isles.

Source
06

Ploemacher et al. 2020

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

The page saysLeprosy was considered a disease of humans, with the exception of the armadillo, so finding it in red squirrels in 2016 was highly unexpected
The source saysIn 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)
The page saysAn Unexpected Reservoir
The source saysThis 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

Source
07

Sainsbury et al. 2008

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

The page saysA study of red squirrels found dead between 1993 and 2005
The source saysused pathological signs and transmission electron microscopy (TEM) to diagnose SQPV disease in red squirrels found dead during scanning surveillance between 1993 and 2005
The page saysfound 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
The source saysSQPV 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.
The page saysThere 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
The source saysThere 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.

Source
08

Schmidt & Fischer 2011

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.

The page saysOn 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
The source saysRats 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

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.