Keeping the Crane River “Crane Friendly”

Editor’s note: This article is part of a series exploring the various facets of the Sandhill Crane Migration in Central Nebraska, the $28 Million annual economic impact that the migration brings, and Audubon’s role in conserving habitat on the Platte River.

This month we ask: “What does it take to keep the river habitat suitable for cranes?”  Many are surprised to find that the sandhill crane migration -and the corresponding tourism industry- are supported by intensive, year-round conservation work.  The story below elaborates on these many efforts to support crane habitat. 

For thousands of years, the Platte River has served as a stop on the crane migration, and for thousands of years those birds knew what to expect when they arrived. Wide, braided, mostly-treeless river channels, bordered by fertile wet meadows brimming with all the food resources cranes need for a successful breeding season. This began to change as European settlers made their mark on the Platte. As they retimed water (ex: using reservoirs to release water at times of their choosing) and removed the forces that had kept the character of the Platte Valley the same all those years, the valley and the river that welcomed the cranes back each year began to change. We began to lose the reason why the cranes came to the Platte annualy, and this loss motivated conservation minded folks to make a positive change to the Platte in the early 1970s.  It was at that time that National Audubon Society and a growing number of partners over the following years began advocating for the protection of the Platte.

Since then, conservation partners have diligently worked along this river to keep it familiar, and useful, to both Sandhill Cranes and endangered Whooping Cranes. Non-governmental organizations like Audubon, The Nature Conservancy, and The Crane Trust (among others) have invested millions of dollars over the years supporting the Platte River through direct conservation action and advocacy work. Often these organizations have worked with state and federal agencies to manage what is called the ‘critical reach’ of the Platte, from Lexington, NE to Chapman, NE.

For the last 20 years, stakeholders in the Platte have also collaborated with each other through the Platte River Recovery Implementation Program which includes other parties such as power and irrigation districts, as well as the states of Colorado, Wyoming, and Nebraska. Collectively, these partners have taken conservation actions to keep the Platte River as high-quality habitat for cranes through much of the critical reach. This habitat requires extensive action both in the channel and on the lands surrounding it, to hold human caused changes at bay and maintain the river closer to its historic state than would be possible naturally within this altered system.

Maintaining the river as suitable habitat is one of the most difficult and expensive tasks for conservation organizations.  Scouring spring floods were once a regular occurrence, removing vegetation from the river channel’s sandbars.  Now, vegetation must be removed manually using heavy equipment to disk sandbars (with costs up to $16,000 per mile) or prevented in the first place with vegetation-suppressing river flows. These flows come from water allocated and stored in upstream reservoirs that US Fish and Wildlife Service can release, to replace missing natural flows. This supplemental water is limited. There is often only enough for one or two months’ worth of flows at 1,500 cubic feet per second (cfs), which is well short of the 35,000+ cfs that the Platte could have historically seen in spring.

Despite mechanical and flow-based efforts, some invasive species like Phragmites pose a major threat of undoing much of this work. The Platte Valley Weed Management Area is a cooperative weed control organization that spends almost $600,000 annually to control Phragmites alone. If not controlled, this species spreads and chokes out river channels at an alarming speed.

Scouring flows are critical to maintain a wide, braided river, but the presence of water is important at other times of year as well. The amount of flow during both the spring and fall migration periods is an important factor in crane’s habitat selection. Cranes select areas with adequate water to serve as an early predator warning system at nighttime roost locations. In short, sufficient water in the river is the best way to keep the Platte healthy… and Audubon advocates to keep natural flows in the river and to prevent further development and diversions.

Beyond the river itself, Rowe Sanctuary’s land managers ensure that our surrounding lands also meet the needs of the cranes. The property is maintained as open, treeless grasslands focusing on providing a diversity of vegetation heights and floral diversity. This supports the widest variety of wildlife and provides the most food resources for cranes.

Our land management practices simulate historic ‘disturbance events’ that once drove the cycle of the prairie, like grazing and fire, to influence prairie plant community composition. We also remove trees encroaching on our prairies and along the river to maintain wide, unobstructed views that are favored for Whooping Cranes as they select riverine roost sites.

Each year, we aim to have around 1/3 of the sanctuary in open short grasses, the preferred structure for cranes to search the grasslands and wetlands for roots, tubers, and insects; all excellent sources of nutrition in contrast to the calorie-dense but nutrient light waste corn cranes spend much of their time feeding on. Diligent work throughout the year controlling invasive plants, conducting prescribed burns, coordinating grazing, and removing trees is all rewarded with the sight of thousands of cranes feeding on Rowe Sanctuary’s grasslands and wet meadows.

The Platte River is one of the great gems of our natural world, thanks in large part to the cranes that rely on it every spring. Just as the cranes rely on the Platte River, the Platte relies on all of us to maintain wide, open, braided channels that are so welcoming for the birds. For more than 50 years, Audubon has been an active part of the collaborative conservation efforts here along the Platte.

It is fitting to realize the incredible dedication and the volume of effort that goes into supporting one of the world’s greatest migrations, for the tens of thousands of tourists who witness it, and for the birds that rely on this river.  Places like Rowe Sanctuary are working diligently so the river can reflect its natural character in a way the cranes recognize.  The marvel of the crane migration is one to protect in perpetuity lest it disappears entirely.  More than anything, we are working to ensure Nebraskans will never have to say, “You should have seen the Sandhill Cranes”.