Tree Sparrows are smaller than House Sparrows, and are more active, often sticking their tails up. The Tree Sparrow has a chestnut brown head and back of the neck (rather than grey) and white cheeks and collar with a contrasting black cheek spot. They’re shyer than House Sparrows in the UK, and are rarely associated with people, although in continental Europe they often nest in buildings just like House Sparrows.
