Answered by Jamie Utz – Wildlife Diversity Biologist – Idaho Dept. of Fish & Game Southwest Region
Thanks to a special feature of reproductive biology, seasonal patterns of torpor, and certain behavioral tendencies of American badgers (Taxidea taxus), this is tricky question to answer. Badgers mate in the late summer or early fall. But once an egg is fertilized, the embryo exists in a sort of limbo stage called embryonic diapause and does not attach to the uterine wall to resume growth until deep into the winter months. Gestation is only 6 weeks long, but this delayed implantation means a female could technically be pregnant for as long as 7 months! Environmental cues like lengthening daylight hours in mid-winter are thought to trigger the resumption of embryonic development. Mothers give birth in late spring to one to five helpless badger cubs who don’t open their eyes until they’re at least a month old. Cubs will begin periodically venturing out of the natal burrow around this time, and will eventually leave their mothers around five or six months of age.
Further complicating the matter of timing with cub emergence is the fact that American badgers aren’t true hibernators. They instead enter into a cycle of torpor during cold winter months, where the badger’s breathing slows considerably and body temperature can drop to as low as 48°F. A badger torpor cycle lasts about 29 hours and is interrupted by a short-lived phase of activity, where a badger might briefly emerge from its subterranean den if the outside temperature is warm enough. Factors like weather patterns and prey availability determine when the badger will shift out of torpor cycles and become more consistently active for the summer ahead.
Finally, there are some key behavioral features of American badgers to consider. Badgers are fossorial, meaning they’re suited to a subterranean lifestyle. They’re extraordinarily strong diggers and will tunnel into the earth to create burrows for sleeping or maternal dens, and can dig with surprising speed in pursuit of fossorial prey species like ground squirrels or prairie dogs. The landscape may be littered with tell-tale badger digs, but a casual observer probably still won’t see one. Badgers tend to be nocturnal or crepuscular, meaning active at dawn and dusk, and take refuge in cool burrows to avoid the hottest parts of the day. Badgers are solitary animals as well, so you’d only ever see more than one together either when cubs are still with the mother or during brief mating bouts at the end of summer.
All of these characteristics make the American badger a somewhat elusive wildlife species, with cubs harder still to spot. But patience and persistence can still reward a wildlife enthusiast! Start venturing out into the field on warm days to look for fresh digs; horizontal claw marks on the sides of a badger-dug hole will distinguish it from digs created by a canid. If you do spot an adult, keep in mind that you could be seeing a male. The only outward sign that could distinguish sex would be evidence of lactation on a female, which is next to impossible to see given the squat, low body shape of a badger. Cubs could potentially be in the burrow but not yet old enough to emerge. A mother badger will return to the same burrow system if cubs are below ground, whereas males can range more freely and may establish a series of burrow systems. Mothers also begin bringing food back to a burrow when the cubs are getting close to weaning age, so keep your eyes peeled for prey items in the jaws of any adults. Good luck!
Thanks to Don Busby for the images and question.