A new study published this month (March 2021) in the journal Ecological Applications shows that the migration habitat for the Whooping Crane is gradually being reduced by the development of wind energy. The researchers found that this endangered bird avoids turbines up to a distance of 5 kilometers and eliminates otherwise useful stopovers if turbines are placed too close to them. According to the authors, five percent of the best stopover has already been functionally lost. There are many more wind turbines in the pipeline, indicating that this situation could get worse if steps are not taken to remove turbines from layovers.
“The results of this groundbreaking study are really enlightening – the expansion of wind energy is already having a negative impact,” says Joel Merriman, director of the Bird-Smart Wind Energy Campaign at American Bird Conservancy. “There are more than 10,000 wind turbines scattered along the Whooping Crane’s migration route. We now know that too many of these turbines are eliminating an important migration stop habitat for this endangered species. “
Each year, the last naturally occurring whooping-cough crane population makes a 5,000-mile round trip traveling south in the spring and north in the fall along a narrow corridor between Canadian breeding grounds and wintering areas on the Texas coast. No marathon flyers, the birds have to stop several times on each season trip to rest and refuel.
Whooping Crane, Copyright Carolyn Fields, from the Surfbirds Galleries
There are a handful of recognized key stops where migratory whooping cranes are reliably concentrated and which are classified as critical habitats by the U.S. Fish and Wildlife Service. However, there are other stopovers that these birds need as a “stepping stone” to complete their journey successfully. Maintaining the availability and quality of these sites is a critical element in the continued conservation of this species. Many are on private land, making protection more difficult. The study shows that these smaller intermediate stops are functionally lost due to the development of wind energy.
And these effects are increasing. In the period of the study from 2010 to 2016, the number of turbines in the middle of the migration corridor has quadrupled. Overall, the placement of wind turbines in relation to stopover habitat at Whooping Crane has been found to be essentially random.
The study shows that whooping cranes avoid areas within 5 kilometers of wind turbines. In essence, the presence of turbines made any habitat at that distance unusable.
This problem will only increase if the turbine siting is not improved. “There is good news here too,” says Merriman. “The study also provides a clear blueprint to prevent the additional loss of migratory habitats from the development of wind energy: avoid placing turbines in the species’ migration path and absolutely make sure they are no more than 5 kilometers from Stopovers are away. “
The whooping crane has been critically endangered for nearly a century. One of the rarest and most endangered North American bird species, the crane’s population had dropped to a low of less than 20 individuals in 1941. After many decades of joint conservation work by US and Canadian partners, the population is now more than 800 individuals. About 500 of these are the only self-sufficient population that nests in Canada’s Wood Buffalo National Park and in winter in and near the Aransas National Wildlife Refuge in Texas. There are two sizable reintroduced populations – a non-migratory flock in Louisiana and a second migratory population in the eastern United States – and approximately 150 birds in captivity.
Wind turbines are unfortunately only part of the problem for whooping cranes. For some wind turbines, especially in rural areas, new power lines have to be built in order to connect the new system to the power grid. Power lines are a leading cause of whooping crane deaths due to in-flight collisions. This is one of the reasons why a permit for the “R Project,” a proposed 200-mile transmission line that would have crossed an environmentally sensitive part of southeastern Nebraska, was revoked this June.
“We need wind power to fight climate change, but we have to be smart about designing facilities,” says Merriman. “This is especially important for rare species like the whooping crane, which have a slow reproductive rate and are therefore less able to recover from loss. These birds have enough challenges including small populations, ongoing habitat loss, power line collisions, illegal shooting … the list goes on. Now they also have to avoid wind turbines. We cannot afford to stand by while the remaining habitat of this species is being lost, especially when this loss is so clearly avoidable. “