Analysis
I. Interpreting Data Plot each column on a circle. For birds orienting to the geomagnetic field without radio interference, what is the greatest difference (expressed in degrees) between recorded vectors and the mean vector of If degrees? For birds orienting with 7 MHz radio interference?
2. Making Inferences,
a. For birds orienting to the geomagnetic field without radio interference, how many of the 12 birds oriented with an accuracy of +/- 30 degrees relative to the mean vector of 16 degrees? For birds orienting with 7 MHz radio interference, how many were +'- 30 degrees?
b. If you were to select a bird at random, what is the probability that it would orient within +/- 30 degrees of the appropriate migration direction (16 degrees north) without radio interference? With radio interference?
3. Drawing Conclusions Is the ability of European robins to orient correctly with respect to geomagnetic fields disrupted by 7 MHz radio frequencies? Is it fair to conclude that the birds' compass sense involves a molecule sensitive to rudio disruption, such as a photoreceptor? That it does not involve particles not sensitive to radio disruption?
Do Birds Use Magnetic Particles as Compass Needles?