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, <br />? <br />35 <br />1981). Several characteristics common to whooping crane roost <br />sites were described by Johnson and Temple (1980) including: <br />(1) Wide channels; <br />(2) Unvegetated; <br />(3) Fine substrate, usually sand; <br />(4) An unobstructed horizontal visibility from riverbank to <br />riverbank of at least 1500 f'eet upstream and downstream <br />(or to a'bend in the river) at all sites: <br />(5) Open visibility overhead, absence of tall trees, tall <br />and dense shrubs, or high banks near the roost; <br />(6) Shallow water except in the main channel (all sites <br />evaluated were less than 12inches deep); <br />(7) Slow flow, about 1-4 miles per hour, although water in <br />the main channel may be flowing faster; (8) Proximity to a suitable foraging site (usually within 1 <br />mile ) ; (9) The presence of unvegetated sandbars with very low <br />elevatiori above water and near the middle of the river; <br />and <br />(10) A distance of at least 0.25 miles from roads, houses, <br />and railroad tracks. Measurements were. made describing the streambed at 19 known <br />whooping crane roost sites on the Platte River during 1983-1988 <br />(Lingle et al. 1984, 1986; J. Ziewitz, pers. comm.). A transect <br />from permanent vegetation on one side of the channel to the other <br />side of the channel through the roost site quantified the <br />following characteristics: . <br />(1) Unobstructed channel width of 172 to 1365 feet; <br />(2) water filled channel widths of 172 to 1207 feet; <br />(3) The percentage of the unobstructed width that was <br />water-filled ranged trom 59 to 100 percent (X=93.3-%); <br />(4) Depths in these channels ranged from 'sandbars up to 1 <br />foot above the water, to channels that were 3.5 feet <br />deep.