Mean directions of migrating monarch butterflies at observation sites are identical to local Kiepenheuer Magnetoclinic routes based on a 'subjective' angle of inclination of 73 12' Methods Determine the bearing for the Magnetoclinic route from the field site based upon a preferred subjective angle of inclination of 75 12'. Categories II and III vanishing bearings should be obtained over a wide range of wind conditions. Proceed with analysis only if mean vector is significant. Examine the Rose diagram. Data analysis to this point has been a standard exercise in descriptive statistics.
More complicated procedures are necessary to continue.
If data are not obviously skewed or bimodal, proceed to Decision Rules. As an exercise, I calculated the eventual destination of migrants from Mississauga, Ontario, based upon a preferred, subjective, angle of inclination 73 12'. This result is intriguing because the lower Great Lakes region has been considered to be the center of distribution of the eastern population in late summer when the migration begins, However, the magnetoclinic route crosses a section of the Gulf and the length of the crossing is much greater for butterflies that start from sites located to the east of the calculated route. Please send copies of all data and data analyses to Tactics and Vectors for inclusion in the Archives. Your data should deposited in the Archives even if mean vectors were not significant.