History of the Wolves on Isle Royale
1949-1980 |
Wolves first made their presence in the 1940s, as they crossed an ice bridge from Canada to Isle Royale, which is about 15 miles long. Once wolves were spotted on the island, a study was started to observe the wolves and moose in 1958. In 1959, there were about 20 wolves recorded and in 1980 there were 50 wolves, two and half times more in 21 years.
|
1980-1989 |
It looked great for the wolf population, but in just two years (1982), the wolf population went from 50 to 14. The blame for this is a disease introduced by humans called canine-parvovirus (“The Population Biology of Isle Royale Wolves and Moose: An Overview”). Later in the 1980s, the wolves began to make a slight comeback, only to decline again.
|
1990-1999
|
Once the 1990s hit, the wolf population was still low, and ecologists were confused as to why it was still down. The reason would ultimately affect the wolves to this day, which is inbreeding. “The poor condition of wolf predation on Isle Royale appears to be caused by inbreeding,” said John Vucetich, Director of Michigan Tech’s study of the wolves and moose of Isle Royale (qtd. in Donovan). A new wolf came to the island in 1997 given the name “Old Grey Guy”. Prior to his arrival, all wolves carried the same genes but with Old Grey Guy now on the island new genes were introduced. Once Old Grey Guy began mating, healthy pups were born enhancing the population.
|
2000- Present Day
|
From 1998 to 2004 the population was thriving because of Old Grey Guy, but in 2006 things would fall downhill again (“All About Wolves”). As the wolf population was increasing, the moose population was decreasing. In 2006, there was a healthy population of 30 wolves split into three packs. Each pack slowly began to fail and in 2011 only nine wolves living in one pack remained. In this one pack, there were recorded two females and with two females the pack began to inbreed. As of 2014-2015 three wolves remain and a natural comeback is very unlikely.
|
What effects the Wolf Population?
Inbreeding
- Causes baby wolves to be deformed and die early in their life.
- It's the leading cause of death among wolves in the park.
![Picture](/uploads/6/7/4/1/67413417/5180016.jpg?309)
The graph at right shows the inbreeding coefficient over the 50 years wolves have been on the island. As you can see in the year of about 1996, a dramatic decrease in the inbreeding coefficient is shown. The introduction of the new non native wolf "Old Grey Guy" came to the island. Before Old Grey Guy, nearly 0.8 (80%) of all wolves had common genes in their packs. Once he began to mate with other wolves, he added new healthy genes to packs and the inbreeding coefficient decrease to 0.1 (10%). Old Grey Guy eventually started to mate with his own relatives on the island because new wolves were not coming to the island. Old Grey Guy did leave the island, but for a time he was very helpful to the island's wolf population. ("The Population Biology of Isle Royale Wolves and Moose: An Overview")
Current Status On Wolves
Currently the wolves on Isle Royale are struggling. There is only three wolves on the island, two adults and one young pup that is deformed. A genetic rescue is almost impossible at this point because of there only being three wolves ("About The Project: Overview"). Only time will tell at this point as we each closer to an end or a new beginning.
Recently uploaded video, informing viewers about the current wolf population as of 2015. Please Watch!
|
|