Fig 1.
a) test apparatus; b) birds (in percent) that reacted to the display of the visual stimulus. c) stimuli: LE: looming eyes, LTS: looming turning spiral (as used on some aircraft), LMS: looming moving spiral, LBD: looming black disc, FBD: static black disc, F Sph: static geometric shapes: sphere (depth impression), S: stripes (used for repelling birds from windows) [35], Fstar: static star, C control: grey screen. Chi-square test, * p < 0.05.; c) The stimulus displayed: LE: looming eyes, looming turning (LTS) versus moving (LMS) spiral, looming (LBD) versus static (FBD) black disc, static geometric shapes: sphere (F Sph), strips (S) static star (Fstar) and control (C).
Fig 2.
The two screens placed back to back on the airport. The basis of both screens was positioned 1m above ground.
Fig 3.
a) transects used for the “entire airport” assessment. The stimuli could be seen at some places within Z1 and Z6 from a distance (> 400 m), red squares: places were observers made recordings; b) the screen area seen from the fixed observation post (within the oblique red lines), the section of the runway were the risk of collisions is the greatest lies between alpha and bravo, blue rectangle: screens.
Fig 4.
Number of birds along the transect.
Numbers of birds (a: raptors, b: corvids) observed along the airport transects in relation to visual access to the stimulus (mean per scan). Chi-square test; *** p < 0.001 (n = 239 scans for the whole study period).
Fig 5.
Numbers of birds in the screen area.
(a: raptors, b: corvids) Numbers of birds in the screen area during the last week (before) pre-stimulus and the first week (during) the stimulus was presented for zones with or without access to the stimuli (mean per scan). Chi-square tests, *** p < 0.001 (n = 121 scans for the 2 weeks).
Fig 6.
Distribution of birds over the whole study period: a) raptors and b) corvids over the screen area before and during display of the stimulus and according to visibility (mean number per scan). Chi-square test, *** p < 0.001 (n = 288 scans for the whole period).