This one is a little easier...
A few quick facts about the short-tailed weasel (Mustela erminea):
- Also called the stoat or ermine, they change coat color from brown to white during winter, yet always maintain a black-tipped tail
- The same species is found across the nothern hemisphere, including Europe and Russia
- These small carnivores live a fast-paced life, where they need to consume nearly a quarter of their body weight in small birds and rodents to meet their daily energetic needs
- To time the birth of their young to when resources are plentiful, females can utilize delayed implantation, where sperm is stored in the female's body for as long as 9 months prior to implantation of the egg in the uterus. Following implantation, gestation of the fertilized eggs to birth of 4-8 kits only takes 4 weeks.
- This high depredation rate and reproductive output makes weasels highly effective predators. However, such efficiency can be a conservation problem when they are introduced to new areas - for example, stoats introduced to the islands of New Zealand are decimating native bird populations and the subject of expensive eradication campaigns.
For more detailed information, see the American Society of Mammalogist species account for the short tailed weasel