An estimated 5,500 American white pelicans so far have returned to the Chase Lake National Wildlife Refuge nesting sites they abruptly quit last spring.

The latest count was done on Friday by a U.S. Geological Survey observer, who canoed to the island nesting sites north of Medina, U.S. Fish and Wildlife Service spokesman Ken Torkelson said Monday.

Torkelson described Friday's pelican count as "incomplete.

"The topography of the main nesting island meant he could not see all of the island from the water, and he did not want to go on the island from the water."

The observer is positive there are eggs on all three islands "because the birds are sticking real close," Torkelson said. "He expects the first eggs to hatch around May 15."

An estimated 30,000 pelicans inexplicably left their traditional summer nesting sites at Chase Lake last spring, but biologists are expecting most to return. Researchers have been unable to pinpoint why the pelicans pulled out and left eggs and chicks behind.

"(The pelicans) are still on schedule as far as I can tell," Torkelson said

Pelicans have yet to occupy the peninsula. Being connected to the mainland, Torkelson said, it's believed to be the least desirable nesting area.

"If you had good houses to pick from and could afford it, why buy a bad house?" he asked.

(Reach reporter Richard Hinton at 250-8256 or outdoors@bismarcktribune.net.)