Guardian: Nearly a quarter of the world’s land mammal species are at risk of extinction, and many others may vanish before they are even known to science, according to a major annual survey of global wildlife. At least 1,141 of the 5,487 known species of mammal are threatened, with 188 listed in the highest risk “critically endangered” category. One in three marine mammals are also threatened, according to the five year review. The “red list” assessment, conducted by the International …