Patterns of Spring Arrival of Maine Migratory Breeding Birds


Since 1994, I have been coordinating a volunteer-based project to monitor the arrival of 130 species of Maine migratory breeding birds. Participants are asked to record their first sighting of all species they encounter along with their geographic location. Six papers have resulted from this work, available for download here.

The Histogram tab provides a graphic of the arrival dates for a species in a particular year. Use the drop-down menu to the left to choose a Species and the slider to pick a year. The binwidth can be changed from one day to ten days with the Binwidth slider. The Data Summary tab gives the mean, median and other quantiles for a Species/Year combination.

The Scatterplot tab produces a plot of median arrival date against year, the North Atlantic Oscillation (a measure of hemispheric weather), or departure of monthly temperature (F°) from the mean. Use the radio buttons to the left to choose an x-variable. The Scatterplot shows the best-fit linear regression through the points and the shaded area represents the 95% confidence interval. See details of analysis in the Regression Statistics tab.



Herb Wilson, Department of Biology, Colby College,