The Nature of Change

The season of fall is upon us marking the transition between summer and winter. Some grumble about what’s to come, but let’s consider for a moment how lucky Iowans are to experience the change in seasons.

In fall the amount of daylight decreases by approximately 3 minutes per day, until the winter solstice on December 21 when we see the least amount of daylight. This shortened photoperiod (the period of time each day during which an organism receives illumination; day length) is a trigger for many plant and animal communities to undergo change.

Trees begin to slow production of sugar or food for the tree. In the process, the green chlorophyll breaks down and the leaves change color and eventually fall off.

Many birds begin to flock together and migrate south to spend the winter in warmer climates. American white pelicans, double crested cormorants, and shorebirds begin to move through first, followed by ducks and geese later in October and November. Some birds like bald eagles and dark eyed juncos migrate here to spend their winters in Iowa!

Birds are the only ones that migrate. Many species of bats, dragonflies and butterflies head south too.

Take a moment and head out to our family of parks to witness this spectacular change of seasons!