Wolverine Birthday 2013

It’s February 14th once again, which, as everyone knows – or should know – is a very important day: Wolverine Birthday. This is the approximate date of birth for wolverines all over the world. Mid-February marks the descent of pregnant female wolverines into their snow dens, there to give birth and attempt to raise their kits, moving them uphill through a series of maternal dens until they are big enough to emerge. This happens sometime in late spring, usually mid-May, after which the kits hang out in their parents’ territories, sometimes alone, sometimes following their mother, sometimes their father, until they set out to find a territory of their own, about a year after they’re born.

A photoshop sketch of a wolverine mom and kits in their snow den, made several years ago and scrapped because it was way too cute, and the kits look weird (also, these guys are a few weeks old, not newborns.) But whatever. Happy Wolverine Birthday.

A photoshop sketch of a wolverine mom and kits in their snow den, made several years ago and scrapped because it was way too cute, and the kits look weird (also, these guys are a few weeks old, not newborns.) But whatever. Happy Wolverine Birthday.

At least, this is the basic outline of the first year of a kit’s life. Bob Inman and Audrey Magoun published a paper in 2012 reviewing all recorded wolverine births, as well as information obtained from trapped carcasses of pregnant or lactating females, and the birth dates generally ranged from late January through mid-March, with reports from the 1950’s of wolverines giving birth as late as April. So the February 14th date is a handy mnemonic device that doesn’t necessarily reflect an absolute reality. The lack of an absolute reality is interesting, as are the reports of much later births earlier in the century and further to the north. Wolverines mate in the summer, but the fertilized embryos don’t implant until later. The exact triggers for implantation (the technical term is nidation) remain unclear, but probably have to do with the female’s body condition – without a certain level of fitness on the part of the female, the embryos will simply dissolve without ever implanting. The range of birth dates means that there is also a range of nidation dates, which could be solely dictated by the percent body fat of the female – or could also be triggered in part by environmental factors. Maybe, then, there’s some range of potential adaptation to changing climate conditions? This is speculative, of course, but if it turns out to be true, it’ll make my valentine’s day every year for the rest of my life.

All of this just complicates my agenda to turn an otherwise annoying holiday into something with real meaning, however. So for now, let’s just stick with February 14th, and I hope everyone out there is having a great Wolverine Birthday. More posts soon!

 

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5 thoughts on “Wolverine Birthday 2013

  1. Our female wolverine, Valentine (!) just celebrated her 7th Bday! The NYS Zoo in Watertown, NY is a perfect place for gulos, and we are excited about this blog-I am spreading the word ! So many people are contributing valuable input for this species.

    • You have a wolverine named Valentine?! That is fantastic. Do you work at the zoo? I’m trying to put together a list of all the zoos in the US that have wolverines – would love to hear more about the Watertown Zoo and about Valentine. Happy Birthday to her, and thanks for reading.

      • Yes, I’m the curator there. Northwest Trek in Eatonville, WA is where Valentine was born. Minnesota, Columbus, Detroit, Mill Mountain Zoo, Henson Robinson Zoo all have wolverines. Our male came from Minnesota, and he will be 14 on February 18th. We’re having a celebration this weekend for them, and will be building lots of snow creatures for them to destroy.

    • To find out more about Valentine the wolverine at Watertown check
      Dallas Laducier’s Wolverine World Tour.(2012). He helped raise
      Valentine asa student &visited her & her companion “Stinky” , took
      photos of them & posted them on the Watertown section of his site.
      P.A.Singletary

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