Crows

Corvids are passerine birds that contain crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family, or, in jargon, corvids. Currently, 133 species are included in this family. Corvids are the largest passerines. They are medium to large in size, with strong feet and bills, rictal bristles, and a single molt each year (most passerines molt twice). Corvids are found worldwide except for the southern tip of South America and the polar ice caps. Most are sedentary and do not migrate significantly. Some corvids have strong organization and community groups, while others can be aggressive. Many species is omnivores but some corvids are predators of other birds and some will eat carrion. The partner bond in corvids is extremely strong and even lifelong in some species. Females can lay between 3 and 10 eggs. Once hatched, the chicks remain in the nests for up to 6-10 weeks depending on the species. Corvids display remarkable intelligence for animals of their size and are among the most intelligent birds thus far studied. Their total brain-to-body mass ratio is equal to that of non-human great apes and cetaceans, and only slightly lower than that of humans.