A satellite tag attached to one endangered Puget Sound killer whale is yielding valuable information about the migration of orcas.

Federal biologists tracking a 22-year-old whale, known as L-87, say he and others have moved moving extensively through the Salish Sea. They have circled an island in the northern Strait of Georgia and made appearances in Puget Sound and the central Strait of Juan de Fuca.

NOAA biologist Brad Hanson says each year of satellite tagging is filling in more gaps about the winter movements of southern resident killer whales. It's also raising new questions about why some travel as far south as Northern California and others may not.

The tag on L-87 shows the orca has been covering about 75 to 100 miles a day since the device was attached on Dec. 26.