Figure 2. Comparison of daily egg turning rates in auklets, gulls, and albatrosses with and without the use of a magnetometer.

Egg turning was measured using egg loggers that had a triaxial accelerometer and magnetometer. However, datasets of ten individuals within each species were compared with and without incorporating the use of the magnetometer data. Shown are means ± SE. Wilcoxon signed-rank tests were used to evaluate statistical differences between turning rates for all individuals within a species. Turning rates were significantly greater for all three species when the magnetometer data were incorporated.