European badgers are fascinating creatures and the more I learn about them, the more interesting they become. One of their most remarkable features is how they mate and the methods they use to try and maximise the number of offspring that they produce.
Badgers live in groups of typically around four to seven individuals. This group is known as a ‘clan’ or a ‘cete’. They are social creatures and will bond with each other through actions such as grooming each other or pressing their bottoms onto another badger in order to leave a scent mark on them.
Another frequent behaviour they display is during mating when the males bite at the necks of the females. This usually takes place within the badger's clan, but males will travel to neighbouring setts to try and mate with a receptive female if one is present.
Badger mating, gestation and birth
Badgers reach maturity at around a year old, but most sows will not have their first cubs until the winter of their second or third year. Mating can happen all year round, but it mainly occurs during two periods – one in January to May and another in July to August. Research suggests that this is when the fertility of the females is highest and therefore mating during these periods is most likely to produce a pregnancy. Badgers don't just mate once though, and females can mate several times with different males over many months.
Cubs can be born from mid-December, but more usually between January and March. Technically their gestation period is only six to eight weeks, yet the female badger may have mated as much as eleven months before giving birth. This long time period between mating and birth is possible due to something called ‘delayed implantation’.
What is delayed implantation
Delayed implantation, also known as embryonic diapause, is where an egg is fertilized soon after mating, but the cub will not be born until several months later. Shortly after mating, the fertilised egg develops into a very early foetus known as a blastocyst; development then slows down almost to a standstill.
The blastocyst floats around in the female's womb until December or early January when the short day length triggers hormonal signals that cause changes in the womb and cause the blastocyst to implant in the wall lining. Once implanted, the early embryo resumes its normal development and completes its transformation into becoming a fully-formed cub.