While invasive plants are of serious concern in the Yukon, we have no invasive animals yet. However, we do have introduced mammals that now call the Yukon home including feral horses and feral cats. There are also many introduced insect species here, like the striped alder sawfly (Hemichroa crocea).
The garden earthworm, which is spreading rapidly elsewhere, does not show a progressive movement in the Yukon.
New research is underway to determine the level of invasiveness and effects of introduced species on natural ecosystem processes.
There are three introduced bird species in the Yukon:
A fourth species, Eurasian Collared-Dove, has been reported recently and might become established.
They all occur in low numbers and therefore are not expected to have a remarkable impact on native species. Although European Starlings likely do displace a few individual cavity nesters, they are fairly rare and the population has been stable over the last 20 years.
Most lakes and waterways in the Yukon are free of invasive aquatic species. There are non-native sticklebacks in two pothole lakes. The rainbow trout in McIntyre Creek and the Yukon River near Whitehorse resulted from lake stocking in the 1950s. The effects of the rainbow trout on native species have not been studied. For more information on Aquatic Invasive Species of concern in the Yukon visit Environment Yukon's website.
Also learn the facts about zebra mussels.