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The Arapaho National Wildlife Refuge is a United States National Wildlife Refuge located in north central Colorado. The refuge is located in North Park in central Jackson County south of the town of Walden. The refuge was established in 1967 to furnish waterfowl with a suitable place to nest and rear their young. It was created in part to offset losses of nesting habitat in the prairie wetland region of the Midwest. It is located in the valley of the Illinois River, a tributary of the North Platte River. It is administered by the United States Fish and Wildlife Service.〔(【引用サイトリンク】title=Arapaho National Wildlife Refuge )〕 ==Description== The dry climate of the area (at an elevation of approximately 8800 feet) requires the diversion of water from the Illinois River through a complex system of ditches to irrigate wetland meadows and fill water fowl brood ponds. Periodic burning, irrigation and various grazing systems are management tools are used on the refuge meadows to maintain vegetative vigor for nesting purposes. Manipulation of water levels in the shallow ponds is intended to assure adequate aquatic vegetation for food and escape cover. The ponds also produce many insects and other invertebrates (protein) needed by most female waterfowl for successful egg laying. These insects also serve as an essential food item for the growth of ducklings and goslings during the summer months. The first waterfowl arrive at the refuge in the spring when the ice vanishes in April. The peak migration occurs in late May when 5,000 or more ducks may be present. Canada geese have been reestablished in North Park and begin nesting on the refuge during April. Duck nesting usually starts in early June and peaks in late June. The refuge produces about 9,000 ducklings and 150 to 200 goslings each year. The Fish and Wildlife Service expects that when refuge lands are fully acquired and developed, waterfowl production should increase significantly. There have been 198 bird species recorded in the refuge.〔(【引用サイトリンク】publisher=USGS )〕 Primary upland nesting species include the mallard, pintail, gadwall, and American wigeon. A number of diving ducks, including the lesser scaup and redhead, nest on the larger ponds and adjacent wet meadows. Most species may be observed during the entire summer season. Fall migration reaches its height in late September or early October when up to 8,000 waterfowl may be on the refuge. Refuge wetlands also attract numerous marsh, shore, and water birds. Sora and Virginia rails - shy, secretive birds - are numerous but seldom seen. If they are present, Wilson's phalarope, American avocet, willet, sandpipers, Greater yellowlegs, and dowitchers will be easy to observe. Other less common species include great blue heron, black-crowned night heron, American bittern, and eared and pied-billed grebe. The upland hills harbor sage grouse year around with a winter population of more than 200 birds. Golden eagles, several species of hawks, and an occasional prairie falcon circle the skies above the refuge in search of food. Their prey includes Richardson's ground squirrel, white-tailed prairie dog, and white-tailed jackrabbit. Badger, muskrat, beaver, coyote, and pronghorn are commonly observed. It is also possible to see a red fox, mink, long-tailed weasel, or porcupine. As many as 400 mule deer have wintered here and up to 200 elk are frequently seen during the winter months. Moose have recently been reintroduced into North Park and may occasionally be observed in the willow thickets along the Illinois River bottoms. There are no venomous snakes in the refuge. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Arapaho National Wildlife Refuge」の詳細全文を読む スポンサード リンク
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