In northern Europe another form of the nuthatch guild is found, known scientifically as _Sitta europea_, whose under parts are white without any washing of buff on the breast.
The Levant furnishes a most charming addition to the feathered brotherhood now under consideration. The scientific gentlemen have christened it _Sitta syriaca_, and its common name is the rock nuthatch, an appellation that is most appropriate, for its chosen haunts are rocky cliffs, over the faces of which it scuttles in the most approved nuthatch fashion, head up or down, as the whim seizes it, clinging with its sharp claws to the chinks, ledges, protuberances, and rough surfaces of the rocky walls. A little larger than its European cousin, its markings are quite similar. In Syria it is common as far north as the southern shores of the Black Sea. Although somewhat shy, it is described as having "sprightly manners and a clear, ringing trill." Odd indeed are some of nature's evolutions, I had almost said caprices, for the rock nuthatch is just as much at home and apparently just as happy on its bleak precipices as is our merry whitebreast in his umbrageous home in the oak or maple forest.
But what kind of nests do the rock nuthatches construct on their limestone walls? That is one of the most interesting features of the life of these birds. One writer[1] who has observed them in their native haunts describes the rock nuthatch as "an expert clay mixer and molder." The bird does not chisel out a nursery in the rock--no, indeed; his method of constructing his nest is as follows: Having found a little hollow or indentation on the rocky wall, he will erect a cap or dome of mortar over it, plastering the structure so firmly against the surface that no rain or storm or predaceous creeping thing can demolish it until long after it has been abandoned by the little architect. The circular base of the nest is ten or twelve inches in diameter. The dome is not entirely closed up, but a small orifice is left in the center, upon the edges of which a narrow neck or funnel, also made of mortar, is raised, the hole just large enough to admit the body of the bird. The funnel is about three inches long.
The building material employed is fine clay softened and glutinated with the bird's saliva and mixed with plant fibers, for the little mason does not believe in making bricks without straw. So well packed is the inch-thick wall that a stiff knife blade must be used to cut through it. While the natural color of the adobe cottage is ash-gray, and therefore harmonizes with the general hue of its surroundings, and also with the mezzotints of the builder, yet he sometimes decorates it with the gaily colored wings of moths caught in the chase and attached to the plaster while it is fresh. The rock nuthatch is as expert a mixer of mortar as the well-known cliff swallows of our own country, and his adobe dwellings bear a close resemblance to theirs.