The Common Raven is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids. There are at least eight subspecies with little variation in appearance, although there are significant genetic differences among populations from various regions. It is possibly the heaviest passerine; at maturity, the Common Raven averages 63 centimetres (25 inches) in length and 1.2 kilograms (2.6 pounds) in mass. Common Ravens can live up to 21 years in the wild, a lifespan exceeded among passerines by only a few Australasian species. Young birds may travel in flocks but later mate for life, with each pair defending a territory. The Common Raven has coexisted with humans for thousands of years and in some areas is considered a pest. Part of its success comes from its omnivorous diet; Common Ravens are extremely versatile in finding sources of nutrition. Some notable feats of problem-solving have been observed in the species, leading to the belief that it is intelligent. Over the centuries, it has been the subject of mythology, folklore, art, and literature. In many cultures, it has been revered as a spiritual figure or god. (Full article...)
Windmills are machines which convert the energy of wind into rotational energy by means of vanes called sails or blades. Originally used for milling grain, they have been adapted to many other uses. This windmill was photographed in Kuremaa, Estonia.