National Geographic : 1982 Apr
SERENADE IN BLUE echoes throughthe twilight depths as humpbacks sing the hauntingsong peculiarto their species. Although other whales and dolphins make sounds underwater,none equals the song of the humpback for complexity andprecision.In a given area, such as Hawaii or off Baja California,all humpbacks sing the same song, composed of two to eight recognizable themes in the same sequence. Research at Maul revealed that singers follow the same patternof behavior,performing alone within 150 feet of the surface, head down, flippers outstretched,and body inclined at a 45-degree angle. To determine the sex of singers, photographerFlip Nicklin trained himself to scuba dive as deep as 130 feet while holding his breath.Approaching a singer from the rear,Nicklin was able to photographthe tail and genital area before exhaling the bubbles that might disturb the whale. The singers proved to be male, and nearly all surfaced for breath during the same theme of the song. "Singing," observes Peter Tyack, "appears to be related to courtship. Singers often interrupttheir song and dash off to join other whales, usually includingfemales." A diver (left)photographsa singer whose heavily scarred dorsal area suggests countless battles over females. The flukes of anothersinger (right) display circularscars left by barnaclesthat dropped or have been scrapedoff. Small fish known as leatherbacks browse along the whale's back.