These birds, against which the hand of every farmer is uplifted, are very shy and cunning; as is well known, they nearly always post a sentinel in some tree top to keep watch while the rest of the flock is feeding in the field below. In the fall and winter, large numbers of them flock, and at night all roost in one piece of woods; some of the "crow roosts" are of vast extent and contain thousands of individuals. Crows nest near the tops of large trees, preferably pines, either in woods or single trees in fields. Their nests are made of sticks and lined with rootlets, and the eggs, which are laid in April or May, range from four to seven in number, are a bluish or greenish white, sparingly or very densely speckled, spotted and blotched with various shades of brown and lilac. Size 1.60 × 1.15. 488a. FLORIDA CROW. _Corvus brachyrhynchos pascuus._ Range.--Florida. This variety has a slightly shorter tail and wings than the last. 490. FISH CROW. _Corvus ossifragus._ Range.--Northwest coast from Oregon to Alaska. This small Crow which is but 16 inches in length, is found only on the coast, where they feed upon shell fish and offal. They nest, as do the Ravens, either on ledges or in tree tops. The eggs resemble those of the common Crow, but are smaller. Size 1.55 × 1.05. 489. NORTHWESTERN CROW. _Corvus caurinus._ Range.--South Atlantic and Gulf coasts, north in summer to Connecticut. From Virginia southward, this small Crow (length 16 inches) is more abundant on the coast than the common Crow which is often in company with this species. Their food consists of grain, berries, and animal matter. Their nesting habits are like those of the common Crow and the eggs are similar and have as great variations, but are smaller. Size 1.45 × 1.05. [Illustration: American Crow. American Raven.] [Illustration 314: Greenish white.] [Illustration: Bluish white.] [Illustration: Bluish white.] [Illustration: Left hand margin.] Page 313 491. CLARKE'S NUTCRACKER. _Nucifraga columbiana._ Range.--Mountains of western North America from Mexico to Alaska.