Red Deer (Cervus elaphus) tracks near a stream in co. Limerick. Red deer is Ireland’s largest land mammal. Their natural habitat is mainly Woodlands, grasslands, moorlands and scrub. They prefer the areas between woodlands and open grasslands. They are herbivorous and usually eat grass and shrubs. Their lifespan is typically 18 years and they can grow up to 1.5m – 2m in length and can weigh up to 250kg. They are protected by Wildlife Act 1976/ 2000.