![Callahan holds a vial full of macroinvertebrates collected from nearby Cold Creek. "These are something that we'll look for in the [vernal] pool too," he said. "This is just from one little scoop of a net. All this life in there — and you'd never know." (Photo: Ellie Katz/IPR News)](https://npr.brightspotcdn.com/dims4/default/005700b/2147483647/strip/true/crop/4032x2483+0+270/resize/880x542!/quality/90/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2F95%2Faa%2F0b5634814a89941ff50482adf099%2Fimg-0537.jpg)
![Sean Callahan points his flashlight toward a brushy section of a vernal pool. One pool that was full last year was noticeably shallower this year. "I can't say the specific reason why," Callahan said. "I have a hunch that when we're missing over 100 inches of snow in this area [this year], that probably influences it at least a little bit. But by studying this and visiting these places tonight, we can hopefully get a few more clues into what's actually going on here." (Photo: Ellie Katz/IPR News)](https://npr.brightspotcdn.com/dims4/default/c951e4a/2147483647/strip/true/crop/4032x2483+0+270/resize/880x542!/quality/90/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2F2e%2Fde%2F5e8e7bb045dea0d6da7994d772b8%2Fimg-0540.jpg)
These shallow pools take shape as the snow melts and spring rains arrive, and then dry up by early fall.
They are key parts of Michigan’s spring landscape, providing breeding grounds for all sorts of insects, frogs and salamanders.
IPR environment reporter Ellie Katz went to Grass River Natural Area in Antrim County, where it’s the job of conservation director Sean Callahan to find the pools, document them and preserve them.
They went out after dark one April night, which is when the pools come to life.
Listen to the audio postcard in the player above.
