Alternative Names (Synonyms)

• Common weasel
• European common weasel
• Least weasel
• Lesser Weasel
• Pygmy weasel
• Kine
• Whittret (Scotland)
• Bronwen (Wales)
• Belette commune (French)
• Mauswiesel (German)
• Zwergwiesel (German)
• Kleinwiesel (German)
• Mustela rixosa (B51)
• Mustela minuta (B51)

Alternative species names (the second part of the binomial species names): [Genus] africana; [Genus] albipes; [Genus] allegheniensis; [Genus] alpinus; [Genus] atlas; [Genus] boccamela; [Genus] campestris; [Genus] caraftensis; [Genus] caucasicus; [Genus] corsicanus; [Genus] dinniki; [Genus] dombrowskii; [Genus] eskimo; [Genus] fulva; [Genus] gale; [Genus] galinthias; [Genus] italicus; [Genus] kamtschatica; [Genus] major; [Genus] meridionalis; [Genus] minor; [Genus] minutus; [Genus] monticola; [Genus] mosanensis; [Genus] namiyei; [Genus] nikolskii; [Genus] numidicus; [Genus] pallidus; [Genus] punctata; [Genus] pusillus; [Genus] pygmaeus; [Genus] rixosus; [Genus] russelliana; [Genus] siculus; [Genus] stoliczhana; [Genus] subpalmata; [Genus] tonkinensis; [Genus] trettaui; [Genus] tonkiensis; [Genus] tretaui; [Genus] typicus; [Genus] vulgaris; [Genus] yesoidsuna; (B141).

Names for new-borns / juveniles

General Appearance

Similar Species

References

Species Author

Major References

Husbandry references:

• Wildlife and Countryside Directorate, Department of the Environment, Transport and the Regions (DETR)
• The Mammal Society
• Mammals Trust

• British Mammal Factsheets

TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

• Mustelids

Specific Needs Group referenced in Management Techniques

• Mustelids

Husbandry Information

Notes

• Accommodation of Casualty Stoats, Weasels etc.
• Hand-rearing Stoats, Weasels etc.
• Catching and Handling of Stoats, Weasels etc.
• Feeding of Casualty Stoats, Weasels etc.
• Release of Casualty Stoats, Weasels etc.

Measurement & Weight

Head

• I3/3, C1/1, P3/3, M1/1.
• Teeth specialised for carnivorous diet. Upper carnassials long and narrow, upper molars transversely elongated.

(B52, B142)

Legs and Tracks

• Five toes on each foot.
• Not webbed.

(B142)

Tail

• Reddish-brown (B142).
• Length: 3-6cm (B142), 1.7-7.8mm (B147); males mean 6.0cm, females mean 5.0cm (B142), male up to 8cm, female up to 5cm (B148).

Coat / Pelage

• Dorsal: reddish brown (russet to ginger brown).
• Ventral: white to cream.

(B52, B142, B147, B148)

• Winter: white (northern and eastern Eurasia), paler than summer otherwise.

Mustela nivalis vulgaris:

• Irregular margin between dorsal and ventral colouration and may have distinct brown spot at corner of mouth, sometimes also brown spots on abdomen.

(B52, B142, B147, B148)

• Two moults per year.
• Timing controlled by daylength.
• Spring moult: slow, starts head, progresses across back to abdomen.
• Autumn moult: faster and in opposite direction.

(B142)

Neonate (New-born) Characteristics

Detailed Anatomy Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

• Reproductive: 3-4 pairs nipples (only visible in adult female), testes in furred scrotum, smaller in winter. Simple uterus (B142).
• Scent glands: anal glands (B142).

Natural Diet

• Mainly small rodents, e.g. bank voles and field voles, wood mice.
• Rats taken more by males than females.
• Young rabbits.
• Also birds and bird eggs.
• Avoid shrews generally (some individuals prefer these).
• Require frequent meals (2-4g, 5-10 times daily) - cannot survive without food more than about 24 hours
• Daily requirement about 1/3 body weight per day: Males 0.33g/g body weight per day, females 0.36g/g body weight/day.
• Increase requirement in pregnancy (6-7% more) and lactation (80-100% more).

(B52, B142, B147)

Detailed Physiology Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Feeding Behaviour

• Localised foraging in good areas.
• Search through vole and mouse tunnels and runways, also mole runs.
• Generally avoid rabbit burrows.
• Locate prey by sight, sound, smell.
• Kill by bite at back of neck.
• Store food for winter.

(B142, B147)

Parental Behaviour

Social Behaviour / Territoriality

• Solitary.
• Separate territories for males and females.
• Males have much larger territories (e.g. 7-15 hectares males, 1-4 hectares females (B147)
• Variation in male territory size depending on food availability and season.
• Male territory enlarges in spring.

(B52, B142, B143)

Sexual Behaviour

Predation in Wild

Activity Patterns

• Active periods 10-45 minutes with rest periods.
• 1-3 rest periods of four hours or more in each day.
• Males more active in spring, females less active.
• Climb well.
• Swim well.

(B142)

• Active day and night.
• Radio-tracking indicates more active in day.
• In captivity more nocturnal.

(B52, B142)

General Habitat Type

• Wide range of habitats - fields, meadows, forests, mountains, riverbanks, lake shores, desert.
• Requires shelter and food available.
• Mainly where small mammals abundant.
• Prefer woodland to open areas in winter in cold climates.
• May spend whole winter under snow.
• In open country stay in areas of cover - hedges etc.

(B142, B143, B148)

Nests / Burrows / Shelters

• Many nests in home range.
• Take over nests of prey - do not construct own nests.
• Also use resting places.

(B142)

Distribution and Movement (Migration etc.)

• Further south into Mediterranean area, North Africa and Egypt than stoat.
• Absent from Ireland.
• Britain: mainland and offshore islands more than 380 square km (including Isle of Wight, Skye, Anglesey, Sheppey). Not found on islands where stoat not found.

(B142, B143)

New Zealand (B51, B142, B143).

Intraspecific variation

• Mustela nivalis nivalis (Northern Scandinavia and Siberia) - White in winter, straight flank line.
• Mustela nivalis vulgaris (Western Europe, including Britain) - Irregular flank line, brown all year.
• Mustela nivalis boccamela Bechstein, 1800 sometimes recognised (Mediterranean).
• Two subspecies in North America.
• Mustela nivalis rixosa Least weasel in North America, sometimes considered separate species (B52).

(B142, B143)

Conservation Status

In Britain: native, common although may be declining. Pre-breeding population estimate of about 455,000, including 308,000 in England, 106,000 in Scotland, 36,000 in Wales. Population estimate was "based on a very limited amount of information for the species" although additional knowledge "may not necessarily have made a substantial difference to the estimate". (B221)

• Bern Convention Appendix III (B143)