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Keep a Phenology Calendar 

April Nature Notes: Tracking Seasonal Changes 
By: Carol McFeeters Thompson  

People have always observed and noted the timing of natural events. Their observations helped them to survive. Each source of food had its time. Waterfowl returned in spring; berries were ripe in summer; nuts were mature in autumn. Nature taught early people when to plant, when to collect maple sap, and when to fish.          

The change of seasons happens in a predictable way. Phenology studies the timing of natural events to discover the rhythms of nature. Aldo Leopold was a famous phenologist who kept records of the seasonal patterns of plants and animals on his farm in Wisconsin in the 1930s. Scientists are using his records today to look for trends in bird migrations and weather patterns.          

You too can create a calendar of natural events that occur outside your back door. By looking at your phenology notebook each year, you can predict the return of the first robin in spring, the appearance of the first monarch butterfly, or the first snow of the season.          

To create a phenology notebook, fill a looseleaf binder with notebook paper and add a divider for each month. Each time you see or hear something of interest, turn to the correct month, record the date on a sheet of paper and describe what is happening and where.

Carol McFeeters Thompson is a regular contributor to OutdoorIllinois and is the site interpreter at Weldon Springs State Park