NEW ORLEANS (AP) – Two young whooping crane couples have laid eggs this year, bringing both hope and disappointment to biologists working to establish a flock of the elegant endangered birds in southwest Louisiana, where they once flourished.

State biologist Sara Zimorski says at least one egg was fertile, but it never hatched because heavy rains flooded the nest.

The other set of eggs was infertile, but those cranes have laid a second pair.

And Zimorski says there’s still time this year for the pair that laid the fertile egg to get back down to the nesting business.

Whooping cranes are among the world’s most endangered birds. There are only about 600 of the graceful, 5-foot-tall cranes, all descendants of 16 birds.