An article about the famous California wolverine, first detected in the Sierras in 2008, came out today in the San Francisco Chronicle. It makes the poor guy sound like a deluded Romeo, reciting the wolverine equivalent of Shakespearean sonnets beneath a balcony that remains stubbornly devoid of a suitable object of affection. As far as anyone knows, this guy is the only wolverine in the state, and his origins remain murky; did he really travel all the way from Idaho on his own, or was he a released captive? His genetics appear to be similar to those of Idaho wolverines of several generations ago, but don’t match the current Idaho profile. Is there an intermediate and undetected wolverine population somewhere between Idaho and California? Or did wolverines make it to California a few decades ago and establish a breeding population that’s maintained that genetic line while the population of origin has shifted?
These questions will remain open for a while. But M56, the wolverine who traveled from northern Wyoming to Colorado last year, traversed sagebrush desert and low hills in order to reach Rocky Mountain National Park, and M57, now living in the Absarokas, was first caught in a bobcat trap outside of Menan, Idaho, either heading into or coming from the sagebrush flats between the Tetons and the Sawtooths. Wolverines are tremendous wanderers, and while high-elevation sagebrush desert may not be suitable long-term habitat, they can certainly move across it between mountain ranges. Males may be the longer-distance travelers, but females are capable of long-distance dispersal as well; a female born in the Tetons in 2004 traveled a straight-line distance of about 187 miles to establish a new home range, but the actual course that led her to the site encompassed a longer and more circuitous route.
This is speculation, but suppose that a female wolverine, in establishing a territory, will select for an unoccupied home range nearest to her place of birth, that allows for adequate food supply for herself and for raising kits, while males will select for the nearest unoccupied home range that allows for adequate food supply and access to a mate. The California wolverine and M57 would, in this hypothetical scenario, indicate that male wolverine home ranges are well occupied through Montana, Wyoming, and Idaho, sending young dispersers farther abroad. Females require slightly smaller territories, so perhaps they haven’t yet saturated the Rockies. But give it a few years, and maybe the California wolverine’s quest for romance won’t be so futile after all. In this context, maybe his efforts to advertise his presence aren’t so pathetic; he’s got enough instinctive knowledge about how his species works to know that one of these days, the girl he’s waiting for will stroll into the mountains just as he did.