Originally published March 17, 2014 at 5:27 p.m., updated March 18, 2014 at 10:31 a.m.
The final numbers for the 2013-14 winter whooping crane survey show an increase in the endangered bird population.
An estimated 304 cranes from the Aransas-Wood Buffalo population wintered in the primary survey area of 154,000 acres on and around the Aransas National Wildlife Refuge, according to a U.S. Fish and Wildlife Service news release.
Last year's wintering survey estimated there were 257 birds, said Wade Harrell, U.S. Fish and Wildlife Service whooping crane recovery coordinator. The confidence interval, a population parameter that describes the reliability of the estimate, narrowed to less than 10 percent this year as a result of more experienced observers, he said.
"The observers in the plane, myself being one of them, are getting better with time," Harrell said.
Last year, the confidence interval was between 178 and 362 birds.