A conservation group says state regulators are to blame for last year's record die-off in the world's only natural flock of endangered whooping cranes, alleging water-use policies dried up food and water supplies in their drought-stricken South Texas winter habitat.
The Aransas Project informed leaders of the Texas Commission on Environmental Quality in a letter Monday that it plans to sue them under the Endangered Species Act to restrict how much water is taken from rivers that feed the crane's coastal nesting grounds.
The commission has allowed too many water permits for the booming areas along the Guadalupe and San Antonio rivers, resulting in high salinity in marshlands and estuaries, the group said. That led to widespread malnutrition and 23 deaths among the crane population during the November to March period -- the most deaths in one winter since 1938 when the U.S. Fish and Wildlife Service began keeping record of the cranes at the Aransas National Wildlife Refuge near Corpus Christi.
In an average winter season, only one crane dies. Only 247 of the birds survived last winter.
"Based upon our studies, we believe that the primary cause of this massive crane mortality is the failure of the TCEQ officials to ensure sufficient freshwater inflows," the letter states.
TCEQ spokeswoman Andrea Morrow said managing river flows is complex and that the agency "curtails, denies or allows diversions as conditions warrant." She said a state law passed in 2007 established a process for managing the flows.
"The TCEQ is confident that this process will enhance our ability to protect wildlife dependent on these flows," Morrow said in an e-mailed statement.
The whooping crane is the tallest bird in North America at about 5 feet. It was near extinction in 1941, with just 15 birds, but has been making a slow comeback. There are three flocks but only one migrates without human help, flying 2,400 miles each fall from Canada to the Texas Gulf Coast.
"They are huge, beautiful, wonderful birds, and to see them malnourished and not making it, it's tough," said Jim Blackburn, attorney for The Aransas Project.
Wildlife experts knew last winter would be tough for the 270 cranes in Texas last year because the south-central portion of the state had been under severe drought since 2007.
The first clue to just how bad it was came in December, when Tom Stehn, the U.S. Fish and Wildlife Service's whooping crane coordinator, happened upon a crane sitting in the grass near a road. Stehn knew something was wrong because cranes rarely sit down, rarely leave the safety of water and will usually take off at the first sight of a human.
But this crane just sat still as Stehn slowly walked toward it, its normally pristine snow-white feathers a grimy gray. He scooped up the crane and it wilted in his arms, without the strength to even raise its head. The bird died minutes later, from starvation.
"He did not try to get away from me. He did not peck at me. He did nothing," Stehn said. "I was amazed because when you're grabbing a whooping crane, they're pretty ferocious. They can peck you in the eyes and skulls and can kill you. ... That meant that crane was in really bad shape."
That death prompted researchers to take a closer look at the entire flock, and they found numerous emaciated birds.
Stehn said it became clear that the drought, coupled with the decreased freshwater inflows, had had drastically reduced water supplies and the cranes' favorite foods, wolfberries and blue crabs. So the cranes had to eat less nutritious foods and burn more energy seeking food and water, Stehn said. That left them weakened and more susceptible to disease as the tougher winter months came in.
This year, there have been healthy rains that have eased drought conditions, but they came too late in the year to help the crabs much and the wolfberry crop was only fair, Stehn said.
"It's not as dire as last fall, but still I'm very concerned," said Stehn, who is hoping all 247 cranes return.
The Aransas Project was required to file the letter of intention to sue because it was suing under the federal Endangered Species Act. It must then wait 60 days before filing the lawsuit.
The group's lawsuit will seek a conservation plan and an injunction barring TCEQ from approving new water permits without assurances that the whooping crane's habitat won't be harmed. The Aransas Project notes the problem goes beyond just the cranes, also hurting the fishing and tourism that are crucial to the region's economy.
A look at the number of whooping crane deaths in the endangered bird's South Texas winter habitat in recent years, according to U.S. Fish and Wildlife Services statistics. Numbers include the crane's peak population for that year and the number to die in Texas.
--2008: 270 cranes, 23 died.
--2007: 266 cranes, 0 died.
--2006: 237 cranes, 0 died.
--2005: 220 cranes, 6 died.
--2004: 217 cranes, 2 died.
--2003: 194 cranes, 1 died.
--2002: 185 cranes, 1 died.
--2001: 176 cranes, 2 died.
--2000: 180 cranes, 6 died.
--1999: 188 cranes, 1 died.
--1998: 183 cranes, 0 died.
--1997: 182 cranes, 1 died.
--1996: 160 cranes, 0 died.
--1995: 158 cranes, 1 died.
--1994: 133 cranes, 0 died.