What the sources say
Pine MartenMartes martes
Every figure, record and mechanism on the Pine Marten profile was written from a source, and this is the working table behind it: 45 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
Vincent Wildlife Trust
Pine Marten. Vincent Wildlife Trust.
- The page saysCream-bibbed tree acrobat with ankles that rotate through 180 degrees for climbing up and down trees.
- The source says
They also have sharp, semi-retractable claws and ankles that rotate through 180 o , which allows them to climb up and down the trees.
Note: source renders the degree symbol as '180 o' - The page saysSharp, semi-retractable claws and ankles that rotate through 180 degrees, letting it climb up and down trees.
- The source says
They also have sharp, semi-retractable claws and ankles that rotate through 180 o , which allows them to climb up and down the trees.
- The page saysplus scrub
- The source says
Habitat: Requires woodland or scrub habitat that provides cover and protection from predators such as foxes
- The page saysrecovering in Scotland, Ireland, Wales and parts of England
- The source says
Today, populations are naturally expanding in number and range in Scotland and Ireland... resulting in the re-establishment of a viable marten population [in Wales]... pine martens are present in Shropshire, Hampshire (the New Forest)
Note: condensed from several sentences on the VWT distribution section; also covers the Forest of Dean and Devon reintroductions cited separately - The page saysVoles and other small mammals, fruit, nuts, eggs, invertebrates, birds and amphibians
- The source says
Small mammals, berries and fruits, invertebrates, birds and amphibians
Note: the facts-box Diet line; 'nuts' comes from the separate mesocarnivore-diet quote used for the body's diet claim - The page saysabout the size of a domestic cat
- The source says
Pine martens are about the size of a domestic cat.
- The page saysusually wearing dark brown fur with a cream-yellow throat patch, or bib
- The source says
Pine martens usually have dark brown fur with a creamy-yellow throat patch known as a bib.
- The page saysunique to every individual, much like a human fingerprint
- The source says
Every pine marten's bib is unique — much like human fingerprints — and can help us to identify individual pine martens.
- The page saysFemales measure 46 to 54 centimetres long, not counting the tail, and weigh around 1.5 kilograms; males run larger, at 51 to 54 centimetres and about 2 kilograms.
- The source says
Identification Female Male length 46-54cm length 51-54cm tail length 18-24cm tail length 26-27cm weight 1.5kg weight 2kg
Note: the identification table's column order is female, then male, for each row (length, tail length, weight); tail length is a separate row, so 'length' excludes the tail - The page saysSharp, semi-retractable claws and ankles that rotate through 180 degrees let it climb up and down trees
- The source says
They also have sharp, semi-retractable claws and ankles that rotate through 180 o , which allows them to climb up and down the trees.
- The page saysmuscular legs and long feet help it leap from branch to branch
- The source says
Muscular legs and long feet help them leap from branch to branch.
- The page saysIn the wild, a pine marten is only likely to reach seven to ten years.
- The source says
are only likely to make it to seven to ten years in the wild.
Note: VWT's 'up to twenty years in captivity' was cut: AnAge's recorded maximum is 18.2 years (one captive animal), used in FAQ 3 - The page saysMeat makes up 30 to 70 percent of the diet, and the rest is fruit, nuts, eggs, invertebrates and fungi
- The source says
pine martens are a medium-sized mesocarnivore whose diet consists of 30-70% meat with the rest consisting of fruits, nuts, eggs, invertebrates and fungi.
- The page saysvoles are a particularly important prey item in Britain
- The source says
In Britain, voles are a particularly important prey item for martens.
- The page saysstudies in Britain and Ireland find red squirrel rarely in a marten's diet
- The source says
studies in Britain and Ireland show a low occurrence of red squirrel in the diet of pine martens.
- The page saysscientists are still not sure why or how this happens
- The source says
Scientists are not sure why or how this happens and further research is needed to fully understand the dynamics between the three species.
- The page saysthey wait until they are two or three years old to start, and breed only once a year, mating in midsummer
- The source says
They don't start breeding until they are two or three years old, only breed once a year... Pine martens mate in mid-summer but give birth the following spring.
- The page saysdelayed implantation, where fertilised eggs sit in the womb without attaching for around 230 days
- The source says
Females have 'delayed implantation', which means that any fertilised eggs are not implanted in the uterus for around 230 days.
- The page saysa strategy that ensures kits are born in early spring, as the weather warms and food becomes more abundant
- The source says
This strategy ensures that the kits are born during early spring when the weather is becoming warmer and food is more abundant.
- The page saysKits are born blind and weigh about 30 grams
- The source says
When born, each kit weighs around 30g. Their eyes are closed and they have a fine covering of silver hair.
Note: ADW corroborates: 'young of Martes martes weigh about 30 g. They are blind, deaf and toothless' - The page saysa litter is usually one to three, but up to four or, rarely, five when food has been particularly abundant
- The source says
usually only have one to three kits (baby pine martens) in a litter... When food has been particularly abundant, pine martens can have up to four or (rarely) five kits.
- The page saysthe young stay in the den, totally dependent on their mother, for about six or seven weeks
- The source says
They will stay in the den for about six or seven weeks and are totally dependent on the mother.
- The page saysPine martens are thought to have been Mesolithic Britain's second most common carnivore
- The source says
The pine marten was thought once to be the second most common carnivore in Britain during the Mesolithic era.
- The page sayswoodland clearance and predator control devastated them; by 1915 they were confined to just a few remote areas of Britain and Ireland and had become the second rarest carnivore there
- The source says
The clearance of woodlands, together with predator control, had a devastating effect on the pine marten population and by 1915 this species was confined to just a few of the more remote areas across Britain and Ireland and had become the second rarest carnivore.
- The page saysFull legal protection came in 1988.
- The source says
The pine marten received full legal protection in 1988.
- The page saysBetween 2015 and 2017 the Vincent Wildlife Trust moved martens from Scotland to mid-Wales, and later projects reintroduced them to the Forest of Dean and Devon
- The source says
VWT carried out a pine marten population reinforcement between 2015 and 2017 by translocating pine martens to mid-Wales from Scotland, resulting in the re-establishment of a viable marten population... Between 2019 and 2021, VWT worked with Gloucestershire Wildlife Trust to reintroduce pine martens to the Forest of Dean; and with Devon Wildlife Trust and other regional partners (2024-2025) to reintroduce martens to Devon.
- The page saysthe Red List for Britain's mammals rates it Critically Endangered in England and Wales and Least Concern in Scotland
- The source says
The pine marten is classified as Critically Endangered in England and Wales by the Red List for Britain's mammals, but Least Concern in Scotland.
- The page saysstudies in Britain and Ireland find little red squirrel in the marten diet
- The source says
studies in Britain and Ireland show a low occurrence of red squirrel in the diet of pine martens.
- The page saysscientists are not sure why or how the shift happens
- The source says
Scientists are not sure why or how this happens and further research is needed to fully understand the dynamics between the three species.
- The page saysIts fur grows thick and fluffy for winter warmth, then comes in shorter and darker over the summer months.
- The source says
During the winter, the pine marten's fur is thick and fluffy for warmth and their summer fur is shorter and darker during the warmer months.
- The page saysin Ireland and Scotland, where martens are recovering, grey squirrels are decreasing and red squirrels are moving back into the woods
- The source says
Research in Ireland and Scotland has shown that where pine martens are naturally recovering their former range and have established good breeding populations, grey squirrel numbers are decreasing, allowing recolonisation of woodlands by red squirrels
- The page saysPine martens are adaptable opportunists.
- The source says
Despite being classified as carnivores, pine martens are adaptable and opportunistic
- The page sayschanging with the season and whatever is locally abundant
- The source says
they change what they eat depending on the season and what is locally abundant
- The page saysA pine marten's ankles rotate through 180 degrees, which lets it climb down trees as well as up
- The source says
They also have sharp, semi-retractable claws and ankles that rotate through 180 o , which allows them to climb up and down the trees.
- The page saysmuscular legs carry it from branch to branch
- The source says
Muscular legs and long feet help them leap from branch to branch.
- The page saystags: omnivore
- The source says
pine martens are a medium-sized mesocarnivore whose diet consists of 30-70% meat with the rest consisting of fruits, nuts, eggs, invertebrates and fungi.
Source
02
Animal Diversity Web, University of Michigan
Martes martes (European pine marten). Animal Diversity Web, University of Michigan.
- The page saysfrom western Europe to western Siberia
- The source says
The European pine marten is distributed through most portions of continental Eurasia from western Europe in the west to western Siberia in the east
- The page saysDeciduous, mixed and coniferous forest
- The source says
prefer forest habitats, including deciduous, mixed, and coniferous forest
Source
03
AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources
Martes martes. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.
- The page saysThe AnAge longevity database lists a maximum of 18.2 years, from one captive animal, and rates its sample size as small.
- The source says
Maximum longevity 18.2 years (captivity) ... Sample size Small ... One captive specimen lived 18.2 years [ 0671 ].
Note: AnAge lists 'Maximum longevity' and 'Sample size: Small' as separate table fields, joined here with the Observations line
Source
04
Sheehy & Lawton 2014
Sheehy & Lawton (2014). Population crash in an invasive species following the recovery of a native predator: the case of the American grey squirrel and the European pine marten in Ireland. Biodiversity and Conservation.
- The page saysA survey of the Irish midlands found the invasive American grey squirrel population had crashed across roughly 9,000 square kilometres of its former range, and native red squirrels were common again after an absence of up to 30 years
- The source says
A distribution survey of the midlands was carried out which confirmed the grey squirrel population has crashed in approximately 9,000 km²of its former range and the red squirrel is common after an absence of up to 30 years.
- The page saysThe authors suggest pine marten abundance may be a critical factor
- The source says
suggests that European pine marten abundance may be a critical factor in the American grey squirrel’s success or failure as an invasive species
- The page saysA study in the Irish midlands found pine marten and red squirrel abundance were positively correlated across the landscape
- The source says
A distribution survey of the midlands was carried out... At landscape level, pine marten and red squirrel abundance were positively correlated
- The page saysat woodland level there was a strong negative correlation between marten and grey squirrel presence
- The source says
a strong negative correlation between pine marten and grey squirrel presence at woodland level was found to exist
Source
05
Abramov 2025
Abramov (2025). Martes martes. The IUCN Red List of Threatened Species 2025: e.T12848A215857966.
- The page saysThe global IUCN assessment lists the species as Least Concern
- The source says
IUCN Red List category: Least Concern (LC). Martes martes (Linnaeus, 1758), IUCN taxon 12848.
- The page saysLeast Concern
- The source says
IUCN Red List category: Least Concern (LC). Martes martes (Linnaeus, 1758), IUCN taxon 12848.
Note: stats.conservationStatus
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.