Overview

• Grey squirrels, introduced to the UK and Ireland from North America, outcompete native red squirrels for food and space, and carry a disease fatal to reds.
• Researchers found grey squirrels have a more diverse gut microbiota, which may give them a health and dietary advantage over red squirrels.
• A specific bacteria in grey squirrels helps them digest calcium from tree bark, possibly explaining their harmful bark stripping behavior.
• The study, published in the Journal of Medical Microbiology, underscores the need for further research to protect red squirrels and forests.
• Future strategies may include promoting healthy gut bacteria in red squirrels or developing new methods to prevent tree damage.