Preview referat: Endangered species
Although peregrines live on every continent except Antarctica, they are always rare. In Arkansas, they're most likely to be seen from mid-September through mid-May in southern lowlands.
The peregrine's recent history holds a cautionary tale. In the 1950s and '60s, these magnificent birds were nearly wiped out when their food chain was contaminated with pesticides, primarily DDT. All 275 known nesting sites in the eastern U. S. were deserted by 1964. To our good fortune, however, they were saved from extinction. There are now more than 1,200 pairs in North America, a four-fold increase in the last 20 years.
Unfortunately, we still have not roused ourselves to face the real enemy. DDT and other persistent pesticides continue to be manufactured and exported to the Third World, and the chemicals currently used in Western countries may be almost as deadly. Many contend we must change agricultural practices on a global scale; only then will we be heeding the message of hope the falcon brings.
In 1994, America's efforts to save endangered species reached a milestone with the announcement by the U. S. Fish and Wildlife Service that the bald eagle had recovered sufficiently to change its status from endangered to threatened in most of the nation. Bald eagle numbers in the lower 48 states climbed from 417 nesting pairs in 1963 to more than 4,400 pairs in 1994. In addition, 5,000 to 6,000 juvenile bald eagles live in the lower 48.
Federal protection and tremendous public support led to this recovery -- through stricter law enforcement, protection of important habitat, reintroduction, a strong public education program and banning of DDT, a pesticide that interfered with normal eggshell production.
The first successful bald eagle nesting since 1930 was reported in Arkansas in 1982. In 1995, 18 pairs of Arkansas eagles successfully fledged young from the nest. An eagle hacking program started by the Game and Fish Commission in 1982 contributed to this resurgence. « mai multe referate din Geografie