Taking all these instances together, the ravens chose by exclusion in 19.17% of all trials in which this was possible (i.e. in "Straight-"- trials and "ST "- trials with serial inspections, in which the empty tube was inspected first), whereas the keas showed such choices in only 3.78% of trials (t-test: N = 17, t = 5.535, df = 15, P<0.001; Fig. 6).
In serial inspections, the birds approached one tube at a time and looked into them consecutively.
For serial inspections, the birds could also stand in the middle between the two tubes, but with their head clearly turned towards one tube at a time.
To assess if the birds would appreciate the impact of the shapes of the tubes on the visual access to the food we additionally measured: Timing of inspection: we distinguished between simultaneous inspections of both tubes and serial inspections.
If the ravens inspected the tubes in "ST"- trials, they were equally likely to inspect both tubes simultaneously as to inspect one tube at a time (paired t-test: N = 8, t = 0.849, df = 7, P = 0.424), whereas the keas nearly exclusively showed serial inspections (paired t-test: N = 9, t = −174.531, df = 8, P<0.001; see also Fig. 4).
CPM transmits the parameters like odometer reading, slip, velocity and time of inspection through serial interface.
Proteins known to be of relatively high abundance in human serum were easily detected by visual inspection of serial gels.
The diagnosis was made by pediatricians based on serial examinations that included inspection and palpation of the genitalia.
Counting and assessment of cell colonies in the agar plates were done by inverted microscopy, computerized image analysis, and inspection of serial photomicrographs of the agar plates.
