Half of future whooper habitat could be lost
Nov. 22, 2014 at 10 p.m.
Updated Nov. 22, 2014 at 10:06 p.m.
About half of the potential whooping crane habitat along the South Texas coastline is projected to be lost to sea level rise.
As the only wild flock of whooping cranes continues to grow, the endangered birds will need more space. For whooping cranes to be listed as threatened instead of endangered, the population must grow to 1,000 birds, a feat that will require 125,000 acres of wintering habitat, according to a recently published study.
Researchers identified where the 5-foot-tall birds might find suitable coastal marsh. But the habitat is largely unprotected land and susceptible to sea level rise caused by climate change and local land subsidence.
The lack of protected wintering whooping crane habitat is the greatest obstacle for the continued growth of the only wild flock of whooping cranes, according to researchers.
The importance of identifying and protecting this land has gained significance as attempts to establish self-sustaining, reintroduced populations of the birds in other parts of the country have yet to be successful, said Elizabeth Smith, a conservation biologist with the International Crane Foundation.
A new study lead by Smith and Felipe Chavez-Ramirez, director of conservation programs for the Gulf Coast Bird Observatory, found that coastal marsh that has food the cranes like and access to drinking water is mostly north of the Aransas National Wildlife Refuge. But about three-fourths of the habitat identified is unprotected land. And bleaker still - about 50 percent may be lost to sea level rise.
The study is one of the first to quantify the cost of sea level rise to wildlife.
"Slowly, we're delving more into wildlife issues, but I think we're still focused on human issues, infrastructure and community issues," Chavez-Ramirez said. "It's important to do both."
By combining Intergovernmental Panel on Climate Change sea level rise models with local land subsidence, Smith and her team found that the sea level around Rockport will rise 1 meter, covering 50 percent of potential whooping crane habitat - a possible 45,000 acres.
The study does not include a timeline of how fast the sea level will change.
As sea levels rise, some coastal habitat will migrate inland. But buildings, roads and other structures will create dikes where water pools behind. Those natural barriers will leave open water on one side and dry land on the other - eroding the land and stopping the migration of coastal marsh, Chavez-Ramirez said.
The loss of coastal marsh could be costly to humans as well because the habitat provides a buffer from storm surges and serves as a host to commercial fishing, oystering and shrimping.
But among the biggest losers to sea level rise will be grassland birds, such as bobwhite quail, loggerhead shrike and Le Conte's sparrow, according to the study. Coastal marsh may migrate inland as grasslands are inundated with salt water. But there will be no areas that will become grasslands because the inland migration of the habitat will be stopped by buildings, roads and other infrastructure.
However, the picture isn't all bleak. With a more defined map of habitat types, the study can be used in the future to help researchers focus their conservation efforts on the area's most important to wildlife survival through land easements or acquisition.
"There's an ecological as well as economic benefit to protecting these habitats," Smith said, "especially for the only wild flock of whooping cranes in the world. If we lose this species here, we lose it forever."
The maps created by the study provide a blueprint for what sea level rise, which is often talked about on a global scale, will look like locally.
"This is my backyard," said Smith, who grew up in Corpus Christi. "It's where I grew up, and it represents how well we take care of our home environment."