Climate change has allowed the red fox to expand its distribution further north (Hersteinsson & McDonald, 1990). This advance has meant that it is now overlapping on arctic fox habitat, known as the arctic tundra (Rodnikova et al, 2011). As both of these foxes have similar habitat requirements, especially their reliance upon small rodents as a food source, their habitat limits are related (Hersteinsson & McDonald, 1990). The limiting factor of the red fox moving north is resource availability and for the arctic fox competition is what determines the limit of its southern range (Hersteinsson & McDonald, 1990). Food availability in winter is a major factor effecting predator success in the arctic meaning the warming climate therefore spells trouble for the arctic fox (Pokrovsky et al, 2015).
The red fox can be up to 70% longer than the arctic and can be twice the weight making them a fierce competitor (Gallant et al, 2012). However this size advantage also means that they have higher energy demands and are more susceptible to starvation and the cold (Pokrovsky et al, 2015). Despite these disadvantages the warming climate seems to be causing the arctic fox to be out competed as the southern end of its distribution has been reduced (Rodnikova et al, 2011). Red foxes have pushed arctic foxes from their dens and taken them as their own (Kim et al, 2013). In an effort to avoid this competition evidence has shown arctic foxes moving their dens higher north and in extreme cases ceasing breeding in the presence of red foxes (Kim et al, 2013). This coupled with some cases of red foxes attacking and killing arctic foxes makes the future of the arctic fox in a warming climate not look pretty (Rodnikova et al, 2011).
|