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. 2011 Oct 26;6(10):e26672. doi: 10.1371/journal.pone.0026672

Table 1. Turtles' homing performances.

Turtle Homing duration Homing length Global efficiency Initial phase Central phase Final phase
CO1 13 days 806 km 0.75 18 0.84 2032 km2
CO2 6 days 447 km 0.72 12 0.80 810 km2
CO3 16 days 1132 km 0.58 0 0.56 648 km2
CO4 10 days 682 km 0.27 0 0.24 769 km2
CO5 9 days 786 km 0.71 0 0.72 865 km2
CO6 6 days 472 km 0.50 0 0.41 3335 km2
mean±SE 10±2 721±103 0.59±0.07 5.0±3.3 0.60±0.10 1410±438
MB1 6 days 484 km 0.63 11 0.68 710 km2
MB2 6 days 641 km 0.69 4 0.83 1289 km2
MB3 15 days 806 km 0.67 6 0.76 2264 km2
MB4a 29 days 2122 km 0.28 0 0.69 43241 km2
MB5 6 days 593 km 0.29 52 0.97 598 km2
MB6b 29 days 1746 km 0.36 21 0.76 14688 km2
MB7 5 days 395 km 0.30 0 0.33 1033 km2
mean±SE 14±4 970±257 0.46±0.07 13.4±7.0 0.72±0.07 9118±6001
MH1 6 days 368 km 0.80 3 0.78 841 km2
MH2c 54 days 3646 km 0.47 15 0.58 37399 km2
MH3 31 days 1870 km 0.55 0 0.80 77896 km2
MH4 23 days 1255 km 0.31 40 0.71 4563 km2
MH5d 18 days 1265 km 0.17 0 0.80 18783 km2
MH6 9 days 643 km 0.29 7 0.23 867 km2
MH7 6 days 463 km 0.42 0 0.44 911 km2
mean±SE 21±7 1359±431 0.43±0.08 9.3±5.5 0.62±0.08 20180±10902
a

came only within 23 km of home in 60 hours; path stopped at 203 km of home (Madagascar).

b

came only within 27 km of home in 14 days; path stopped at 256 km of home (Aldabra).

c

came within 21 km of home in 44 days; path stopped at 112 km of home (battery exhausted).

d

came only within 13 km of home in 4 days; path stopped at 227 km of home (Madagascar).

The global path and central phase efficiencies were estimated as the mean cosine of directional errors. The initial phase efficiency was estimated as the number of 5-km steps travelled (with respect to water masses) before the turtle considered definitely took the correct ±90° direction. The final phase efficiency was estimated as the mean of the squared distances between successive locations and home when the turtle came within 50 km of home. CO: control group; MB: magnetic treatment on the nesting beach, prior to displacement; MH: magnetic treatment during homing.