New way of counting whooping cranes detailed at public meeting in Fulton

Oct 12, 2012 | Corpus Christi Caller-Times by Julie Silva | Related Press

FULTON — Keeping tabs on whooping cranes in the Coastal Bend long has been a rudimentary process involving aerial flights.

However, the U.S. Fish and Wildlife Service and Aransas National Wildlife Refuge are hoping that technology will play a larger role in documenting the endangered birds.

Agency officials conducted a public presentation Thursday night that centered on traditional counts and how biologists are moving forward without the service’s longtime whooping crane coordinator.

Tom Stehn, who counted whooping cranes for almost 30 years, retired a year ago. He had

intimate knowledge about the habits of cranes and when he conducted aerial flights he often was able to track down birds that had moved from one site to another.

“He wanted every single bird in the population to be counted,” said Brad Strobel, a refuge biologist who is developing a new methodology to count the birds. “That was the goal. Everybody can understand that that’s phenomenal. Tom did a phenomenal job, but at this juncture, as much as I wish I could channel Tom when I’m in the aircraft, I can’t.”

Refuge officials counted 254 whoopers in January. In Stehn’s last count, he found 278 birds had survived the 2010-11 season. It’s unclear if the difference is the new counting method that relies on estimates, whether drought conditions forced birds to move elsewhere or if they died.

Strobel emphasized that the agency is doing the best it can without Stehn’s historical knowledge. The agency monitors 140,000 acres of whooping crane habitat.

About 50 people showed up to learn about the new methodology. Many questioned the change in counting methods while others expressed frustration that they hadn’t received an update on the crane count since Stehn retired. He provided updates twice a year.

Nancy Brown, in charge of public outreach for the service, said the agency is posting information on its website rather than sending it out via the email list that Stehn used. The agency also created a website to report crane sightings.

The agency in its counting methods has mapped out whooping crane territory and determined which areas had the most amount of salt marsh, the habitat favored by whooping cranes. Using data from several aerial flights combined with computer mapping software helps biologists come up with an overall estimate.

One audience member criticized the margin of error in the new methodology, stating that the estimate isn’t good enough.

“As you’ve heard, people are accustomed to getting pretty reliable estimates,” he said. “Plus or minus 30 birds; a lot of people aren’t going to see that as an improvement.”

Strobel said estimates will improve with each flight. He added that he’s confident the figure he came up with is close.

“I think we need to keep in mind that last year was an exceptionally dry year, and birds were doing things that we’ve never seen before,” Strobel said. “Had Tom been in the aircraft, we don’t know what figures he would have come up with.”

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