Garrulus glandarius, commonly known as the Eurasian Jay, is native to a wide range of areas across Europe, North Africa, and much of Asia. Its geographical distribution extends from Western Europe, including the British Isles and Scandinavia, to the eastern parts of Asia in countries like China and Japan. The species is also found in North Africa, particularly in the Maghreb region.

The Eurasian Jay primarily inhabits deciduous, mixed, and coniferous forests, especially those with a dense understory. It is adaptable to various types of woodlands, including oak and pine forests, and is also found in urban areas with substantial tree cover. These birds thrive in environments that have ample cover and a diversity of tree species.

The Eurasian Jay plays a crucial role in seed dispersion, particularly acorns, thereby contributing to forest regeneration. It is an omnivorous bird feeding on a wide array of food sources including seeds, fruits, invertebrates, small vertebrates, and occasionally eggs and chicks. The species adapts to seasonal changes by storing food such as acorns, which highlights its important ecological niche as both a disperser of seeds and as a control factor for insect populations.