Prairie pothole
|
Left behind by retreating glaciers, a mosaic of shallow, seasonally
flooded wetlands imprints the northern plains. Fed by snowmelt
and rain, the potholes are breeding oases for most of North Americas
ducks. The birds build nests in the fringing marshes and adjacent
uplands, fortifying themselves for egg production by feeding on
the stew of invertebrates and aquatic vegetation. From the bottom
(above), diving canvasback ducks pull duck potatoes, fleshy tubers
of the arrowhead root. Located in rich farmland, potholes have
been relentlessly drained, despite their role in recharging aquifers.
|
|