Loons on Crescent Lake are spotted by Nathan Kimble and his son, Alex, during their half-hour loon count Saturday morning. Volunteers surveyed lakes and ponds statewide for Maine Audubon to count loons and collect data for conservation efforts.

Alex Kimble, 10, looks out on loons a few yards away from him and his dad, Nathan Kimble, on Crescent Lake. The Kimbles volunteered for Maine Audubon to count loons near their lake house.

A loon comes up out of the water while fishing for food on Crescent Lake Saturday morning. Over 850 volunteers surveyed lakes and ponds statewide for Maine Audubon to count loons and collect data for conservation efforts.

Loons on Crescent Lake Saturday morning spotted by Nathan Kimble and his son, Alex, during their half-hour loon count Saturday morning. Over 850 volunteers surveyed lakes and ponds statewide for Maine Audubon to count loons and collect data for conservation efforts.

Nathan Kimble and his son, Alex, 10, count loons on Crescent Lake in Raymond on Saturday. Volunteers fanned out statewide to count loons that they spotted during a single half-hour for Maine Audubon's annual tally.

Nathan Kimble, right, and his son, Alex, 10, uncover their boat to get ready to count loons on Crescent Lake in Raymond on Saturday morning.

Nathan Kimble tries looking skyward to spot loons In Raymond on Saturday. The presence of loons is a good indicator of lake health, experts say.