A moonlit walk by the River Suck in Roscommon, where thinning flocks underline modern realities

On days like these, with limited daylight, the full moon is doing the sun’s work. One early evening during the week, I walked the River Suck outside Castlerea in Roscommon, and the moon carried me along, lighting my way as it reflected off the river and the pools of water that had gathered in nearby fields.

The Suck is a river of Roscommon, a county that largely sits on 350 million-year-old limestone riddled with cracks, cavities and channels. Water appears and rapidly disappears; it’s a county of swallow holes and sinkholes, turloughs that fill and vanish with the seasons, underground rivers, streams and springs where water slips out of view shortly after it surfaces.

Water can move quickly through the rock, creating a system where river and groundwater are almost one. Roscommon is a long county, about 100km from north to south, and rivers gave the county much of its…