The young Eurasian tree sparrow has down covering its body, which helps retain heat. An adult Eurasian tree sparrow possesses a short, strong beak that allows it to crack seeds and catch insects, and thin legs with gripping toes for perching on branches and buildings. The plumage of an adult includes a brown cap on the head, white cheeks with black spots, a brown back with dark stripes, and a light gray belly. Wings allow the species to quickly fly short distances between shelters.