INTRODUCTION: Birds regularly @entity238 in conditions of reduced visibility where they cannot see the horizon, whereas @entity1 pilots under similar conditions are subject to @entity911 ( @entity911 ) and must, therefore, rely on instruments to maintain safe flight. We surmised that pigeons whose eyes were covered and that were rotated in a centrifuge before flight might show signs of @entity911 . METHODS: We built a small centrifuge ("ornifuge") that allowed us to @entity42314 a bird around the vertical axis of its head at 1 cps for a specified number of turns and then release it instantly through a trap bottom to @entity238 free. We studied 67 cull racing pigeons once each under four conditions: 1) static with normal vision (Static-See, n = 13); 2) static with eyes covered (Static-Cover, n = 17); 3) @entity42314 with normal vision ( @entity42314 -See, n = 15); and 4) @entity42314 with eyes covered ( @entity42314 -Cover, n = 22). Flight behavior immediately on release was observed by the investigators and photographed to document the occurrence of initial hovering, direction of spontaneous rotation if any, and staggering after landing. Birds released with eye-covers flicked them off within a few moments. RESULTS: Both Static-See and Static-Cover birds flew normally. For @entity42314 -See, most flew normally, but 27% hovered momentarily before flying away. Among @entity42314 -Cover birds, abnormal flight was seen in 50% and 72% staggered after landing. DISCUSSION: Spinning in the ornifuge produced abnormal flight behavior in the majority of blind-folded birds. This may provide a model for examining certain aspects of @entity911 experienced by pilots under instrument meteorological conditions and studying the mechanisms that make birds relatively resistant to @entity911 .

Avian flight without visual reference: preflight spinning produces XXXX .

@entity1 :: ('9606', 'Species') :: ['human'] @entity42314 :: ('45380(Tax:7227)', 'Gene') :: ['spin', 'Spin'] @entity911 :: ('MESH:D003221', 'Disease') :: ['SD', 'spatial disorientation'] @entity238 :: ('7227', 'Species') :: ['fly']
@entity911 :: (MESH:D003221,Disease) :: ['spatial disorientation']
