It is quite common for people to get confused between an ermine and a weasel as they are both very similar. They are animals belonging to the same family. Both are generally called weasels; however, there are distinct differences between the two that set them apart, and thus, they are regarded as different species.
Ermines vs Weasels
The main difference between Ermines and weasels are that they are two different species of animals. They belong to the same family and genus as Mustela, but they are two entirely different species. Many characteristics like size, colour, habits, and other features set them apart from each other.
Ermines are the common name for the animal with the scientific name of Mustela erminea. Mustela erminea Or commonly called ermines, are small squirrels like animals with long tails and slightly larger bodies. They are generally soft brown coated animals with a black-tipped tail with a carnivorous habit. They also change colour in the winter.
Weasels is the common name for the animal with the scientific ne of Mustela nivalis. Mustela nivalis Or commonly called weasel, is also small squirrels like animals much like ermines. They have similar habits and habitats but differ in their coat colour. They have a coat of reddish-brown colour that also changes in the winter.
Comparison Table Between Ermines and Weasels
| Parameters of Comparison | Ermines | Weasels |
| Size | Ermines are usually larger than weasels ( 7-13 inches). | Weasels are usually smaller in size (8 inches). |
| Weight | Ermines usually weigh more than weasels. | Weasels being smaller weigh less than ermines. |
| Tail | Ermines have a longer tail with a black tip. | Weasels have a shorter tails with no distinctive colouration. |
| Coat | Ermines in the summer have chocolate brown coat and white in the winters. | Weasels have a reddish brown coat in the summer and white in the winters. |
| Gestation | Ermines have a longer gestation period than weasels which is almost thrice the time. | Weasels have a shorter gestation period than ermines. |
What is Ermines?
Ermines are mammals that belong to the family of Mustelidae. They are small, soft-bodied animals belonging to the Genus of Mustela. Ermines are the common name of the species Mustela erminea. They are also known as stouts or short-tailed weasels, northern stouts or even Bonaparte weasels.
Ermines can be distinguished from the other five species of weasels by the colouration of their fur and size. Ermines are generally chocolate brown coloured animals. Their fur is soft and changes colour in the winter to white. In the summer, the chest and stomach area remains white. The characteristic of an ermine is its tail.
An ermines tail is almost one-third of its body and has a black tip. This back tip is more prominent in the winters when the animal turns white. It is usually around 7-13 inches in size and weighs around 120-150 grams. It’s a small animal, yet it is bigger than the least weasel. Also, their larger size contributes to their more weight than the weasels.
They are active animals that feed on insects, invertebrates, bird eggs and other small animals. They also are common prey of cats, foxes and badgers. They are abundantly found in the United States. They also give birth to many young at once that can be from 3-18 in number in 280 days.
What is Weasels?
Weasels are also mammals that belong to the family of Mustelidae. They are small, soft-bodied animals belonging to the Genus of Mustela. Weasels are the common name of the species Mustela nivalis. They are also known as lesser or least weasels.
Weasels can be distinguished from the other five species of this genus by making a close examination of their fur colouration and their size. Weasels usually have reddish-brown coloured fur, which is generally not as soft as ermines. Also, this colour lasts only in the summers and in the winters, they change the colour of their fur to white.
At this stage, they look pretty much alike an ermine except for the fact that they do not have a black tail tip like that of an ermine. They are usually less than 8-9 inches in size and also weigh much less than ermines. However, they do have a longer tail than ermines that is almost two-thirds the size of their body size.
They are also very agile animals with similar feeding habits, but due to their small size, they fall prey to a larger set of animals which also include predatory birds like hawks and eagles. They are also very abundant. They give birth in smaller batches of 5-6 young in a shorter reproductive period of about a month and 10 days.
Main Differences Between Ermines and Weasels
- Ermines are commonly called stouts, while weasels are the common name for least weasels.
- Ermines being larger, have a different set of predators than weasels, which are more susceptible to a larger number of predators.
- Ermines usually give birth to more young than weasels and also have a larger reproductive cycle of about 280 days in comparison to 34-37 days of weasels.
- Ermines have a black coloured tail tip that is very prominent in the winters when their fur turns white, while no such tip colouration is present in the least weasels.
- Ermines also tend to have softer fur than weasels and thus are more commonly hunted than weasels.
Conclusion
Ermines or weasels are terms for specific species of the Genus Mustela. Each of the terms can not be used interchangeably to refer to the other organism in a strictly biological sense. However, in day to day terminology, weasels is a widely used term for all the species of the Mustela Genus.
Ermines and weasels are commonly mistaken for each other in the winters when they both turn white, but they can be told apart if looked at the tail. Also, ermines have a history of being hunted and pelted for their soft fur to make coats for royals, while weasels have shorter and harder coats that are not usually pelted.
References
- https://www.jstor.org/stable/1375093
- https://academic.oup.com/jmammal/article-abstract/66/4/745/848104