Acoustic detections of singing humpback whales in deep waters off the British Isles

From October 1996 through September 1998, we used bottom-mounted hydrophone arrays to monitor deep-water areas north and west of the British Isles for songs of humpback whales (Megaptera novaeangliae). Singing humpbacks were consistently detected between October and March from the Shetland-Faroe Isl ands south to waters west of the English Channel. Temporal and geographic p atterns of song detections, and movements of individually cracked whales, e xhibited a southwesterly trend over this period, but with no corresponding northward trend between April and September. These results, together with a review of historical data from this area, suggest that the offshore waters of the British Isles represent a migration corridor for humpbacks, at leas t some of which summer in Norwegian (and possibly eastern Icelandic) waters . The migratory destination of the detected animals remains unknown, but th e limited data suggest that these whales are bound primarily for the West I ndies rather than historical breeding areas off the northwestern coast of A frica. Humpbacks detected in British waters after early to mid-March probab ly do not undertake a full migration to the tropics. These data provide fur ther evidence that singing is not confined to tropical waters in winter, bu t occurs commonly on migration even in high latitudes.