Gretchen Gerrish

Commentator - Field Notes

Gretchen Gerrish works for UW-Madison's Trout Lake Station through the Center for Limnology. She studies how evolutionary and ecological processes interact to allow natural systems to deal with change over time.

Most of her work focuses on zooplankton, microscopic invertebrates that provide the food-web link between fish and algae.

Steve Gerrish

Making national headlines, the 17-year cicadas were making a ruckus throughout eastern parts of the US leaving me to wonder, why don’t we see cicada swarms in the Northwoods of Wisconsin?

Cicadas have a limited and mostly eastern distribution in the United States, reaching as far north as New York state, down to Louisiana and Georgia in the south and barely extending into Kansas and Oklahoma in the west. They hatch on 13- or 17-year cycles and specific cohorts, which are also known as broods, hatch in offset years.

I spent most of my life not knowing that porcupines could climb trees. While I am a little embarrassed to admit this fact, I am also not sure I spent a ton of time in my younger years thinking about it. Now that I know, I have become obsessed with staring toward the tops of trees trying to find a bound-up ball of quills, nested in the highest branches.

Joe Giersch, USGS Northern Rocky Mountain Science Center

Walking from my truck into work last week, I noticed a frail looking insect flitting along the surface of the snow on the trail in front of me. On closer inspection, it was a stonefly. Stoneflies are small insects that live most of their lives in streams and rivers, emerging only to complete their reproductive life cycle. Like stone flies, many aquatic insects, including many flies, mosquitos, dragon flies and damselflies have a life cycle that is partly in water and partly above water. But, most of these species emerge and take flight in spring and early summer.

As air temperatures in fall fluctuate between freezing at night and sunny 70 degree days, many deeper lakes within the region experience a phenomenon known as turnover. Journeying into the science of fall turnover can lead you into a wide berth of topics including physics, chemistry, thermodynamics, and biology. While complex and varied across systems, fall turnover influences how we use and interact with our beloved regional lakes.

Image by umsiedlungen on

Have you ever seen a bee emerging from a hole in the ground in the spring? There are many ground nesting bee species in Wisconsin and for this month's Field Notes, Gretchen Gerrish tells us more.

Image by Jim Arnold

For this month’s Field Notes, Gretchen Gerrish of UW-Madison’s Trout Lake Station tells us of the life and death of leaves.

With wide eyes and anticipation, many stare to the skies on the night of December 24th to watch for the outline of a tiny sleigh and eight flying reindeer. But, how did Santa first come about?

turn off your computer and go outside/flickr

It’s the second Tuesday of the month, which is when we hear from our commentators in the field.

This week, Gretchen Gerrish of UW-Madison’s Trout Lake Station tells us about darkness as a resource.