Chuck Bednar for redOrbit.com – @BednarChuck
The wolf population at Isle Royale National Park in Michigan has reached a historic low, with only three members of the group remaining alive – just one-third the amount that were spotted in 2014, according to wildlife experts from Michigan Technical University.
The 57th annual report on the park’s wolf and moose populations, which was released last Friday, also found that there is an estimated 1,250 moose that live on the island, and that a pair of wolves visited the area before trekking across an ice bridge to the mainland, the researchers said.
The Isle Park survey is the longest-running predator-prey study in the US, they added, and this year’s report highlights a growing chasm between the predators and the prey that Michigan Tech scientists said that they have been closely monitoring over the previous four years.
Combination of inbreeding, population decline problematic
John Vucetich, an associate professor of wildlife ecology who co-led the study with Michigan Tech research professor Rolf Peterson, explained that the main cause of concern was not just the presence of the wolves, but whether or not they are performing their ecological function.
Last April, officials from the park said that there was still a chance that the gene pool could be replenished naturally, since the creatures are able to move to and from the island across those ice bridges. However, now that there are only three wolves remaining, Vucetich said that the odds are that it is too late for scientists to perform genetic rescue on the species.
He added that one of the wolves left Isle Royale last winter, leaving two adults and one pup (possibly the offspring of the two adults) remaining in the park. The pup does not appear to be in good health: it has a constricted waistline, poor posture and what appears to be a deformed tail, the apparent result of inbreeding among Isle Royale wolf packs in recent years.
The Michigan Tech team said that it would not be a surprise if the pup was dead by this time next year, but even if it was in good health, it would not necessarily be a promising sign for the health of the population, they explained. Since 2009, the population has decreased by 88 percent, raising serious questions about whether or not the species can recover.
Is there hope for these wolves, and should experts intervene?
According to the researchers, geneticists monitoring the wolves’ situation agree that it is not likely that the wolves are doomed without new genetic material, and that even if the adults are a mating pair, their offspring would most likely not fare well. If the adults are a mating pair, they probably would not be interested in other potential mates that could be introduced.
RedOrbit contacted Peterson and asked him about the declining Isle Royale wolf population, and whether or not anything could (or should) be done to help the creatures recover. He pointed us to a 2012 case study, published in 2012 by the George Wright Forum (a thrice-annual journal of the George Wright Society, a group of professionals on behalf of parks and protected places.)
That paper, entitled “Should Isle Royale Wolves be Reintroduced? A Case Study on Wilderness Management in a Changing World”, discusses “important values to be considered when charting an administrative response to the wolf decline,” Peterson told us via email. In that paper, he and his co-authors discuss whether it is ethically appropriate to intervene to save the wolves.
“Only once in recorded history has a breeding pair of wolves capable of founding a population immigrated to Isle Royale,” they wrote, adding that “even the most optimistic scenarios include an elevated risk of extinction for at least the next several years.” Even so, as the 2012 case study indicates, there are no easy answers when it comes to the issue of intervention.
Unlike wolves, moose are thriving – which isn’t good either
In addition to the declining wolf population, the research uncovered a growing imbalance between predator and prey, as the moose population at Isle Royale has been increasing at a 22-percent rate over each of the past four years – a potentially harmful trend.
If the trend continues, moose could become as abundant as they were in 1996, when the creatures has a significant impact on forest vegetation, Vucetich and Peterson wrote. Experts are growing concerned that the increasing numbers of moose, which is due in part to the woes of the wolves (their natural predators) could cause long-term harm to the ecosystem
“[In 1996] the moose population had considerable impact on forest vegetation,” Peterson and Vucetich wrote in their new report. “Concerns remain that the upcoming increase in moose abundance will result in long-term damage to the health of Isle Royale’s vegetative community.”
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