Bird migration perils cold temperatures on the wintering grounds kills thousands of birds, resulting in 30-90% population declines of migratory birds. For example, between 27000 and 62000 ducks, mostly tufted duck and common pochard, starved to death during a very cold winter in March 1986. The passing of Migratory Bird Treaty (US, 1916) and Migratory Birds Convention Act (Canada, 1917) made it illegal to kill or capture migratory birds. Even though migratory bird acts were passed at the beginning of the 19th century, many countries still have no laws or programs to protect migratory birds. International bird trade is a multibillion-dollar industry and
What is a Masterpiece? confluence of memories and emotions forming a single idea", that it has "a power of recreating traditional forms so that they become expressive of an artist's own epoch and yet keep a relationship to the past". The highest masterpieces are said to be "illustrations of great themes." Clark also implicitly excluded the erotic from considerations of what constituted a masterpiece, based on his perspective that a necessary condition is the balance between sense and form (works that are too sensual are, therefore, unbalanced and not to be categorised at masterpiece level). What is a Masterpiece? What is a Masterpiece? is