Mild weather delays whooping crane migration to area

By By JJ Velasquez - jvelasquez@vicad.com
Originally published November 25, 2009 at 4:06 p.m., updated November 25, 2009 at 8:45 p.m.

AUSTWELL - Mild weather up north is keeping many endangered whooping cranes from reaching the end of their migration corridor at Aransas National Wildlife Refuge, a refuge specialist said Wednesday.

Vicki Muller said 99 whooping cranes have arrived to date, including 5 juveniles.

The refuge expects at least 247 cranes to return because that is the number that left early this past spring.

Specialists believe most of the endangered birds are in Oklahoma, where temperatures remain in the 50s.

"This normally doesn't happen," Muller said. "But due to the warmer climatic conditions, there hasn't been very harsh weather to push them down here."

Most of the birds typically arrive by this time of year, Muller said. She said all the cranes usually arrive by mid-December.

When the birds arrive, the drought-affected environment will pose challenges to keeping them healthy, Muller said.

Higher salinity levels in the bay waters have pushed their main food source, blue crabs, away from the marshes where cranes usually look for prey.

Muller said the crabs usually breed in the shallow bay waters where they are accessible to the cranes but not when salinity levels are high. The saltier waters also make it hard on the birds because they have to look for alternate water sources.

The cranes' other prime food source, wolfberries, should be in good supply this season, but because they provide less nutrients than the crabs, the refuge will look to supplemental food sources such as roasted acorns, deer feed and crane chow.