Seeds are Priceless Gold Mined by Migratory Birds on RWB Wetlands

Story By: Steve Mosley in partnership with the Rainwater Basin Joint Venture

Near Funk, Nebraska – Tiny, almost microscopic seeds to be consumed by migrating birds in the millions are a treasure stitched into the fabric of Rainwater Basin wetland habitats. Seeds that remain provide the seedbank necessary to replenish the next year’s plant community perpetuating the cycle of renewal.

More than 240 species of plants grow in Rainwater Basin wetlands; many are good, some are undesired and others are invasive.

Not so easy, this business of restoring Nebraska’s wetlands, then preserving, protecting, expanding and nurturing them in perpetuity.

The wetlands in question lie within the sprawling footprint of the Rainwater Basin Joint Venture … the operating word being ‘venture’ as in a diverse coalition of public and private partners who bring to the task their unique assets, be they land, infrastructure, scientific expertise, boots on the ground or vital financial support.

Nebraska’s Sandhills, the largest intact grassland in the world, stand in contrast to the Rainwater Basin’s playa (clay based) wetlands of southcentral Nebraska.

The Rainwater Basin is a patchwork quilt of private and public wetlands across 6,100 square miles covering all or parts of 21 counties and five Natural Resource Districts. Prior to settlement there were 11,000 playa wetlands covering 204,000 acres. Over time fertile soils, abundant groundwater and the need for crop production supported the expansion of croplands across this landscape, as a result 90% were drained for crop production.

Despite the great loss, today an estimated 10 million migrating waterfowl, 500,000 shorebirds and federally endangered whooping cranes still depend on these wetlands during spring migration.

The grass buffers associated with the wetland are paradise for pheasants, deer and myriad ground-dwelling animals.

Studies prove quality and availability of habitat in spring migration staging areas like the Rainwater Basin directly impact migratory bird populations across North America.

For those and endless other reasons, growing, restoring and tending the health of this one-of-a-kind habitat is the year-round mission of the Rainwater Basin Joint Venture partnership.

One example among decades of projects is in progress this fall at Funk Waterfowl Production Area (WPA), located south and west of Kearney north of the village of the same name.

Like most Phelps County wetlands, Funk WPA was substantially diminished by wetland drainage, land leveling and sedimentation that supported cropping prior to US Fish and Wildlife Service (USFWS) ownership.

Much of the developed farmland in Phelps County benefited from irrigation water provided by the Central Nebraska Public Power and Irrigation District (CNPPID) canal system.

In the 1980s and 1990s, wetlands like those at Funk WPA ponded water because of excess runoff from flood irrigation systems that surrounded this large wetland. That changed, however, with the arrival of pivot irrigation. As a result, runoff that filled wetlands spiked sharply downward.

This fall at Funk WPA, work focuses on removing fill material and sediment that has accumulated atop the clay (playa) pan because that material – a foot thick tangled mat in places – must become fully saturated before water can pond at the surface. After this material is removed, the much less -permeable clay soils saturate quickly, causing the basin to seal. Once sealed the wetlands quickly pond water.

Wetland management is important in maintaining high quality habitat. Tools include everything from prescribed fire to grazing, herbicide application, disking, roto tilling, excavation, haying, shredding, mowing and water level manipulation.

Of equal concern to scientists is how the nutrient-rich soil above the clay encourages invasive species. These species thrive and spread by root growth. Unmanaged, invasive species do not produce the volume of seeds and reduce access to available ponded habitat needed during migration.

Migrating clouds of waterfowl must have seeds to complete their arduous, annual journey and therein lies the problem.

An October 7 tour of the Funk project with USFWS biologist Jeff Drahota was eye-opening; the work on this single project runs the gamut from heavy equipment scraping away sediment to precise elevation and angle. The excavation restores the basin floor to pre-settlement conditions.  Infrastructure of water control structures and pipelines are the final elements of a project that took years of the planning and hard work needed to allow runoff and supplemental water to reach the wetland.

What happens to all those tons of unwanted soil?

Its value is “big for cropland and cattle feeders,” was Drahota’s answer, “five adjacent landowners help dispose of the spoil piles.”

The Funk WPA is just one among hundreds in the Rainwater Basin covering 2,000 acres. That’s good because larger wetlands are key habitats for whooping cranes and migrating waterfowl. These expanses provide resting and feeding areas for all types of waterbirds.

Drahota explains, “Bigger ponded areas” result in “higher ponded frequency, and can support thousands of waterfowl during stopover periods. Large expanses provide resting and feeding areas for all types of waterbirds.”

The same work discourages undesirable plants, too.

Taking out the soil not only changes the elevation (fostering surface ponding), but also removes accumulated nutrient content, Drahota added.

That sounds counterintuitive to gardeners in town who pile all the fertilizer and compost they can find under their tomatoes and cucumbers. Not so here, where seed-rich native plants thrive with just a thin skin of soil atop the clay.

“It’s not about making it deeper,” said Drahota, “it’s about increasing ponding frequency and therefore increasing emergent annual plant growth, ultimately increasing energy available to waterfowl. Seeds are duck feed.”

It also looms large that annual plants favor conditions that allow sunlight penetration to expose the ponded water.

The point is made obvious in the accompanying photo of Drahota buried to his waist in reed canary grass. Even if there was a foot of ponded water at his feet, birds could not possibly use the choked mess.

High-nutrient soil like this, he said, is “where invasives take over. They are very water thirsty and thick,” he added. As a result, no ponding.

Of the long list of partners standing shoulder-to-shoulder in the Rainwater Basin Joint Venture, Drahota said, “Interests might not be identical, but we’re all working for the same outcomes that provide high quality wetlands.”

Partners supporting this project through financial or technical assistance included: CNPPID, Ducks Unlimited, Natural Resources Conservation Service, Nebraska Department of Natural Resources, Nebraska Environmental Trust, Tr-Basin Natural Resources District and the USFWS.