The problem is, the vast majority of the recovering population is geographically confined to one small region northeast of the Nanaimo Lakes on Vancouver Island. This leaves them vulnerable to random localized events having an exaggerated effect on the species. This is why the Marmot Recovery Foundation is working so hard to increase the marmot’s distribution to include more of their historic range.
“Developing a reasonable distribution of inter-dependent colonies in the other regions safeguards the species by spreading the risk,” said the Foundation’s Executive Director Viki Jackson. “If a colony becomes threatened (or worse) colonies scattered nearby will repopulate it. The same theory applies to distinct metapopulations, which historically provided a safety net for the species that allowed them to survive for thousands of years.”
Poor first-year survival of the captive-born marmots, being released to rebuild the developing colonies, has increased the challenge of recovering these regions. But Mount Washington itself is providing answers.
Supplemental feeding, known to increase pup production in most species by improving the spring condition of the females, was begun at the Mount Washington colony in 2011 initially to discourage the marmots from putting themselves at risk, by leaving the colony in search of food, when the prolonged spring snow conditions limited their food supply.
“It worked! The marmots stayed put and a boon of pups was born, encouraging us to attempt supplemental feeding at more sites,” said Viki.
The boon of pups are not only a boost to their natural colonies, they provide an opportunity to include a few wild-born marmots, with higher overwinter survival, in with the release groups. The wild marmots should have an advantage establishing themselves at the developing colonies where the captive-born marmots are struggling to gain a foothold.
Mount Washington is also serving as a “preconditioning” colony to see if first-year survival of the captive-born marmots can be improved by releasing them here first, where they can be easily fed and monitored, for their first hibernation in the wild before they’re trans-located to the developing sites the following year.
So far results are very positive. Overwinter survival of the first test group at Mount Washington was 70% compared to first-year overwinter survival of captive-born marmots at some of the sites in the central and northern regions that has been as low as 10% – 30%.
The Mount Washington tests have provided new techniques to help the marmots overcome the “first-year hurdle” in the developing regions. Including wild-born yearlings and “pre-conditioned” captive-born marmots in the release groups may provide the advantage the marmots need to become reestablished at these important historic colony sites, safeguarding the long-term viability the species.
To learn more about the Vancouver Island marmot visit the Foundation’s website at www.marmots.org
Photos by Jared Hobbs, courtesy of the Marmot Recovery Foundation.