New research by Queen’s University Belfast shows that native European pine martens (Martes martes) predate on non-native grey squirrels (Sciurus carolinensis) significantly more than red squirrels (Sciurus vulgaris).
The findings, published in Mammalian Biology earlier this year and funded by UK wildlife charity People’s Trust for Endangered Species (PTES), also show that although both squirrel species are on the pine martens’ menu, pine martens predate on grey squirrels exclusively in spring and summer, during the squirrels’ breeding season.
As such, it’s now thought pine martens may raid grey squirrel nests (known as ‘dreys’), specifically targeting juveniles and females caring for young. This provides a plausible mechanism for the decline in grey squirrels seen across Ireland and Britain.
The research, led by Dr. Joshua Twining from the School of Biological Sciences at Queen’s University Belfast, also showed that pine martens do predate on native red squirrels, but at a much lower level. Red squirrels have adapted to live alongside pine martens in the evolutionary landscapes of Europe, thus, red squirrels appear to have a greater awareness of the threat posed by pine martens. Grey squirrels may also be energetically more valuable, and therefore preferable to predators like pine martens as they are larger and are found in higher numbers than red squirrels.
The paper, entitled "The dynamics of pine marten predation on red and grey squirrels", can be accessed here. To find out more about this project, click here, and to find out more about PTES’ internships visit here
Posted On: 10/08/2020