The Vancouver island marmot, as it’s name indicates, naturally occurs only in the high mountains of Vancouver Island, British Columbia. They are one of the largest marmot species and are easily identified by their unique appearance. However, this endemic Vancouver Island animal is one of the most critically endangered mammals in the world (All About Marmots, 2008).
In the mid-1980’s, the marmot population on the island was estimated to be over 300 individuals. Sadly, by 2001, their numbers had declined to less than 75 animals (Government of Canada, 2008). This decline is due to a multitude of factors, including human activities, disease, and climate change (affecting where they live and reproduce since they typically live in high-elevation environments); unlike many other cases of endangered species, habitat loss and destruction does not appear to have been a factor (Bryant and Blood, 1999). The major threat to the marmot is predation – at least 80% of mortality is attributable to predation, especially by wolves, cougars, and golden eagles (Bryant and Blood, 1999). The cougar and wold numbers on Vancouver Island have increased dramatically since the 1980’s, which doesn’t help the situation.
There has been many previous actions that groups and organizations have taken in order to help the marmot populations increase, including re-introductions.A study by Aaltonen and colleagues focus on the success rate of captive-born marmots into natural habitats in order to determine whether and to what extent survival and mortality rates of captive-born marmots differ from those of their wild-born counterparts (Aaltonen at el. 2009). By using radio-telemetry and mark-resighting methods, they estimated seasonal and annual survival rates of the marmot to compare the survival and mortality rates of captive-born marmots versus wild-born marmots. They also focused on the effect of age-at-release on survival (Aaltonen et al. 2009).
Their results indicated that annual survival of captive-born marmots released into the wild was low compared to wild-born marmots; marmots released as 2-year-old or older survived more successfully than those released as yearlings (Aaltonen et al. 2009). They found that annual survival rate was lowest for pups and highest for yearlings and adults. Forensic evidence suggested that predation was the most important cause of mortality. What their results indicated was that by delaying the release of captive-born marmots until 2 years of age, their probability of survival in the wild was increased, and thus will improve the success of the release program (Aaltonen et al. 2009).
The Vancouver Island marmot is still listed as endangered today, and their only chance for survival is ultimately up to us. By taking the results of the discussed study and re-introducing marmots at a later age, we might see marmot populations dramatically increase, making the cost associated with rearing marmots for an extra year well worth it.
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Aaltonen, K., Bryant, A., Hostetler, J., Oli, M. 2009. Reintroducing endangered Vancouver Island marmots: Survival and cause-specific mortality rates of captive-born versus wild-born individuals. Biol Cons, 142(10): 2181-2190. doi:10.1016/j.biocon.2009.04.019
All About Marmots. [Internet]. The Vancouver Island Marmot [cited March 23 2016]. Available from https://www.islandnet.com/~marmot/
Bryant, A. and Blood, D. 1999. Vancouver island marmot: Ministry of Environment. Available from http://www.env.gov.bc.ca/wld/documents/marmot.pdf
Government of Canada. [Internet]. Species at risk public registry: Vancouver island marmot [cited March 23 2016]. Available from http://www.registrelep-sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=136