The first whooping cranes of the season have arrived at Alabama’s Wheeler National Wildlife Refuge along the Tennessee River.

The Decatur Daily reported that the endangered birds, which spend the winter at the 35,000-acre (14,164-hectare) refuge in north Alabama, began showing up this week.

About a dozen whooping cranes wintered at the refuge last year. Adults are identifiable by their white bodies, red crowns, black wing tips and whooping sound.

The birds started spending the winter in north Alabama in 2004 and have attracted bird watchers from across the United States. The popularity of the birds led Wheeler to create the Festival of the Cranes, planned for Jan. 14-16.

Along with the whooping cranes, the festival celebrates the more than 10,000 sandhill cranes that winter at Wheeler.