Despite a mortality of 69.0 per cent in [313] nests, 24.9 per cent in [792] chicks, and 19.6 per cent in [296] adults . . . the late-summer populations showed 255 to 311 per cent increases over the breeding populations during the 3-year period of 1948-50."Crop harvest activities destroyed 35 per cent of all nests, 8 per cent of all chicks, and 28 per cent of all nesting hens.Weather was second in importance as a mortality faetor.--