An estimated 80 percent of the wild whooping crane population has settled into the marshes along Texas' central Gulf Coast after 10 groups of the rare birds were confirmed in North Dakota this fall.

The number of birds confirmed in the sightings was 27, two of which were juveniles.

Tom Stehn, whooping crane coordinator for the U.S. FIsh and Wildlife Service, estimated 211 cranes, including 30 chicks, have arrived on the Texas coast after conducting his first aerial census last week. He estimates another 30 to 50 cranes still are en route from their summer nesting grounds in northern Alberta, Canada.

Whether any more whooping cranes will pass through North Dakota this fall is anyone's guess.

"There are lots of sightings in Oklahoma," said Martha Tacha, the coordinator for the whooping crane monitoring project. "There might be some (pass through), but it's getting pretty late for North Dakota."

The last confirmed sighting in South Dakota was Nov. 3-4, she added.

"Some with young may dally," said Paul Van Ningen, the USFWS state whooping crane coordinator for North Dakota, who's the manager of Long Lake National Wildlife Refuge near Moffit. "Some don't have the urgency to get south, and with the mild weather, we have had open water."

There was a probable sighting of three whoopers last week near Turtle Lake.

They were flying about a quarter of a mile away, and the observer did not have binoculars, said Van Ningen. To be confirmed, a sighting must be verified by a wildlife biologist or other veteran observer.

The 30 chicks are an "indicator of good survival," Stehn wrote in an e-mail summary of his census. Eighty-four chicks, including 28 sets of twins were hatched at their Wood Buffalo National Park breeding grounds, a June survey showed.

Stehn expects a record number of the protected whoopers to arrive on the Texas coast. Biologists are hoping for 250 or more. Last year, the crane population in Texas peaked at a record 237; however one crane was found dead this spring south of Mandan. It apparently died during its northern migration.