A few hours after her release on Thursday, F3 returned to the same trap from which she’d just been liberated. She didn’t spring the trap again, but she seemed intent on assessing the bait as a food source.
To Jason, this indicates that she is not denning. She’d been in the trap for about four hours when the field crew let her out, and if she had kits they would at most be about three weeks old and still dependent on regular nursing and care (for all their reputation for ferocious independence, wolverines are tiny and helpless for the first few weeks of life.) She should have immediately returned to them; the fact that she came back to the traps instead suggests that there are no kits.
On the other hand, the behavior could also indicate that the den is close to the traps, and that F3, being familiar with the locations of the traps for the past few winters, situated her den in a way to take advantage of a reliable food source during the period of denning that would most restrict her own travel. Flights on Friday and Saturday located her within a few miles of the traps, and we are about to begin a series of intensive flights that should tell us whether she’s truly localized, or is just hanging out in the area for a few days before heading off on a broader sweep of her territory. M57 is on the move; although the exact role of wolverine fathers in kit-rearing remains unclear, there’s evidence that they do play a role, and his wide-ranging travels might also indicate that F3 is not denning.
As an aside, I have no maternal instinct toward human infants; my friends tell me that they’re having babies, and it’s nice for them, but beyond being happy that my friends are happy, I’m really not that interested in the actual babies. But for some reason the question of whether or not our project wolverines have kits has me on tenterhooks every year. When there are more than six billion of any species, I find it hard to be enthusiastic; when you’re one of a population that might number 100, suddenly you are much more intriguing. Besides – and this is perhaps not cool to admit as a wildlife scientist, but I make no apologies – wolverine kits are cute.
Here are a couple of pictures of wolverine kits: one of a newborn wolverine kit that was brought to an animal rescue operation in Canada, and the other of wolverine biologist Jeff Copeland holding an older kit in Glacier National Park. There’s also some good information on the Glacier Park Project, including some nice maps of wolverine movements, on this page.