A study by the International Union for Conservation of NatureNTER NATIONAL(IUCN) in conjunction with BirdLife lnternational states that approximately 49% ofbird species are endangered and continue to decline in numbers. Meanwhile, 38%of them are in a stable state, while only 6% have seen their numbers increase. Protected areas have disappeared because of the accelerated urbanization andindustrialization of mankind, with overexploitation leading to the disappearance ordeterioration of some forest areas. About 277 of them are in critical condition andneed to be re-established. While two thirds of all birds (71%) live in forests, theabsence offorests, trees, nesting sites and food sources is an important factor inthe extinction and endangerment of birds.