Fauna of Nicaragua Many of Nicaragua's birds are brilliantly colored, including various species of parrots, toucans, trogons, and hummingbirds. guardabarranco is the national bird of Nicaragua. Natural range for the scarlet macaw has been vastly reduced by the pet trade. Most of the Pacific region of Nicaragua no longer is inhabited by the species. Nicaragua is home to many nesting populations of sea turtles, including the hawksbill sea turtle, leatherback sea turtle, loggerhead sea turtle, olive ridley sea turtle, and the Pacific green turtle ("Chelonia mydas agassisi"). All of these are endangered or critically endangered species, with declining global populations. Extensive efforts are
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to