Article Abstract:
Populations of northern harriers and short-eared owls have both experienced declines in several parts of their North American ranges, but little is known about how they respond to grassland management. A new study examines the nest-site selection by northern harriers and short-eared owls on two remote intensively managed grasslands in Illinois. The study shows that northern harriers prefer to nest in undisturbed areas with tall, dense cover. In comparison, short-eared owls commonly nest in areas of short cover. To provide appropriate habitat for both species requires a mixture of both managed and idle grasslands.
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Article Abstract:
Female ring-necked pheasants commonly parasitize the nests of other species, including those of the greater prairie-chicken, and have been implicated in the decline of an isolated prairie-chicken population in Jasper County, IL. A new study investigates parasitism of prairie-chicken nests by ring-necked pheasants over an extended period. The study finds that parasitism incidence rose from 2% to 42% between 1970 and 1987, suggesting that it reduced prairie chicken productivity. A major factor is the dependence of both species on limited nesting habitat.
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Article Abstract:
Genetic data for several populations of prairie-hens suggests the establishment of a demographic barrier to viable diversity in one of the four populations examined. Hatchability rates for Greater Prairie Hen population in Illinois have declined, unlike populations in Kansas, Minnesota and Nebraska that do not face such barriers. The Illinois decline in genetic diversity is probably caused by extreme demographic contraction.
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