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Fig. 2. Trajectories to a food site from displaced (D1, D2, D3) and training (T)
start points. For clarity, not all the recorded trajectories are plotted. We
show 13, 13, 10 and 13 releases from sites D1–D3 and T, respectively,
and the mean vectors of all the first segments (grey arrows). Mean vectors are
measured with respect to the direct line between each starting point and the
food site. The direction and 95% confidence interval of each mean vector are
D1: 4.76±6.61°, r=0.95, N=30; T:
–2.20±6.62°, r=0.94, N=34; D2:
11.9±7.82°, r=0.93, N=29; D3:
14.4±18.4°, r=0.87, N=13. Data come from 12 ants.
Solid black circles indicate cylinders, and F indicates the food site. Food
was removed during these tests.
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and its direction relative to F2 by the angle 
.
and
ß in inset), are plotted against each other for successive blocks of 10
trials after the switch. (A) Paths 1–10: N=70, mean
X=30.47±3.26°, mean Y=3.71±15.62°,
direction of principal axis=92.08°. (B) Paths 11–20: N=102,
mean X=26.47±3.435°, mean
Y=–7.79±14.355°, direction of principal
axis=89.98°. (C) Paths 21–30: N=86, mean
X=25.38±2.78°, mean
Y=–7.62±6.9°, direction of principal
axis=80.23°. The closeness of the principal axis to 90° indicates a
lack of correlation between the directions of the two segments.
2=22.9,
d.f.=2, P<0.001). Accuracy improved between the first and the
second blocks of trials but not afterwards (Mann–Whitney test: first
block vs second block, z=–3.965, P<0.001;
second block vs third block, z=–0.437,
P=0.662). (B) Similar histograms showing changes in the distance of
the turn from the ant's starting position. The distance between the start and
the turn decreased as training progressed (Kruskal–Wallis test:
