7. Uurgemiddelden grafieken
Club van Zeetrekwaarnemers Verslagen , Volume 27 - Issue 1 p. 18- 27
In the following figures the mean numbers of birds per hour per seven-day period are given for each coastal region. In these the mean numbers of birds flying northwards (eastwards) are plotted above the abscis, while the mean numbers of birds flying southwards (westwards) are plotted below it. In the figures periods with less than three hours of observation are not represented, this is indicated by an asterisk (*).
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