Least Weasel (Mustela nivalis)

OTHER NAMES: Weasel
Latin Etymology: Mustela ("weasel") nivalis ("snowy")

Adult Least Weasel (subspecies M. n. nivalis) at Summer Leys, Northants - September 2025

Featured Subspecies: Mustela nivalis nivalis
Weight: 29-270g  /  Length: 130-260mm
IUCN Red List: Least Concern

The Least Weasel is perhaps most notable as the smallest of all of carnivora in not just the UK but the entire world - and also among the most broadly distributed being found across most of the Northern Hemisphere.  Despite it's tiny size however, it is proportionately an incredibly powerful predator - for an animal whose skull can apparently fit through a wedding ring they can take down prey that is vastly larger than them such as rabbits.  A widely common species throughout the UK, but also rarely seen - I've only seen a handful ever and always unexpectedly.

Related Species:
Order: Carnivora 
Family: Mustelidae 
Genus: Mustela 
SUBSPECIES: M. n. nivalis, M. n. allegheniensis, M. n. boccamela, M. n. campestris, M. n. caucasica, M. n. eskimo, M. n. heptneri, M. n. mosanensis, M. n. namiyei, M. n. numidica, M. n. pallida, M. n. pygmaea, M. n. rixosa, M. n. rossica, M. n. russelliana, M. n. stoliczkana, M. n. tonkinensis, M. n. vulgaris, M. n. vulgaris

 - Sighting Locations -

UNITED KINGDOM - Description

 - Seen at Rainham Marshes and Geddington.

Further Notes: BirdForum Opus, IUCN Red List, RSPB, Wikipedia, Xeno-canto .

Stoat (Mustela erminea)

OTHER NAMES: Ermine, Short Tailed Weasel
Latin Etymology: Mustela ("weasel") erminea ("ermine")

Adult Stoat (subspecies A. a. stabilis) at Wooler, Northumbria - July 2009

Featured Subspecies: Mustela erminea stabilis
Weight: 260g  /  Length: 17-32cm
UK STATUS NOT EVALUTATED / IUCN Red List: Least Concern

Possibly the easiest to see of the UKs seven mustelid species, it is still however, quite an unusual occurrence to see one. It looks superficially similar to the weasel, but can be told apart by the substantially larger size and black tip to its tail. As with many mustelids, it is proportionally an incredibly powerful predator - killing animals many times its size and weight such as rabbits.  The Stoat in the UK remains brown throughout the year, but in more northerly populations they grow a thick white coat for camoflage during Winter, and it is in this form they are known as ermine and have been hunted for their fur in the past.

Related Species:
Order: Carnivora 
Family: Mustelidae 
Genus: Mustela 
SUBSPECIES: M. e. erminea, M. e. aestiva, M. e. alascensis, M. e. anguinae, M. e. arctica, M. e. augustidens, M. e. bangsi, M. e. celenda, M. e. cigognanii, M. e. fallenda, M. e. ferghanae, M. e. gulosa, M. e. haidarum, M. e. hibernica, M. e. initis, M. e. invicta, M. e. kaiacensis, M. e. kaneii, M. e. karaginensis, M. e. lymani, M. e. martinoi, M. e. minima, M. e. muricus, M. e. nippon, M. e. ognevi, M. e. olympica, M. e. polaris, M. e. richarsonii, M. e. ricinae, M. e. salva, M. e. seclusa, M. e. stabilis, M. e. stratori, M. e. tebedina, M. e. tobolica 

Further Notes: BirdForum Opus, IUCN Red List,  RSPB, Wikipedia, Xeno-canto .