Humpback Whales Fact Sheet Humpback Whale. Image: QM The Humpback Whale (Megaptera novaeangliae) occurs The extent of black pigmentation varies between the in all oceans of the world. Its predictable migration routes southern hemisphere stocks, with those from the Atlantic between winter breeding and summer feeding grounds being more heavily pigmented than whales from the once made it an easy target for whalers. Drastically Pacific. Occasionally completely black individuals are seen depleted in all regions by the 1960s, the species was in eastern Australian waters, and an all-white (probably given complete protection by the International Whaling albino) individual has been a regular visitor here in the Commission in the southern and northern hemispheres in past. The dorsal aspects of the pectoral flippers of northern 1963 and 1966 respectively. hemisphere humpback whales are white, whereas those of southern hemisphere whales are black. The southern hemisphere baleen (filter-feeding) whales were designated into six areas or groups by Because of the seasonal variation between the the International Whaling Commission on the basis of hemispheres, there is little opportunity for northern and longitudinal segregation. Those which migrated along the southern whales to meet and mix. For example, during the eastern Australian coast were known as the Area V (130ºE- northern winter, whales from that hemisphere are located l70ºE) stock and those which migrated along the western in near-equatorial breeding grounds while the southern Australian coast were the Area IV (70ºE-130ºE) stock. hemisphere stocks are feeding in Antarctic waters. The geographic and climatic isolation has resulted in Humpback Whales measure about 4 m in length at birth, observable DNA differences between various stocks. following an 11 month gestation period. They double their size within a year, by which time they are weaned. Physical Pigment variations extend to individuals. Photographic maturity is reached between 5-10 years and the average catalogues of these unique markings, along with scars and length of adult whales is approximately 14-15 m. Females tail fluke serrations, have now been established for many are slightly longer than males. Sexual maturity is reached areas, including the eastern Australian coast. This method before physical maturity. Although it is theoretically possible of individual identification enables long-term studies of for a sexually mature female to calve at yearly intervals, it migrations and reproductive rates. is likely that calving is followed by one or even two resting Barnacles are common on humpback whales, most years. The minimum life-span of individuals in the non- frequently about the head, chin, leading edges of the exploited state is about 20-25 years. pectoral flippers and genital aperture. Species such as The extreme length of the pectoral flippers (approximately Coronula diadema and C. reginae become attached during one-third of total body length) distinguishes the Humpback the polar summer and drop off when the whales enter Whale from all other baleen whales and is the reason for temperate waters. Resultant surface scars are invaded by the generic name parasitic whale lice, particularly Cyamus boopis, which may cause extensive tissue destruction. Megaptera (= big-winged). The slapping of these large pectorals during courtship or play was once erroneously Southern hemisphere humpbacks feed almost exclusively attributed to attacks by thresher sharks. on the small crustacean known as krill (Euphausia superba), which occurs in vast quantities in Antarctic Colouration is basically black dorsally and white ventrally. waters. A feeding whale gulps a huge mouthful of water www.qm.qld.gov.au © The State of Queensland, (Queensland Museum) 2011 and krill and raises its tongue towards the roof of its mouth, forcing the water out through the baleen plates attached to the upper jaws. The baleen bristles (greyish-white in this species) act as sieves to collect the krill, which is then swallowed through a relatively small gullet. The song of the Humpback Whale is the subject of intense study and speculation. The calls are highly structured and complex and may be repeated for hours on end. The members of each stock sing the ‘same’ song and it is changed from year to year. It appears that only males sing and the song is produced most frequently at or near the breeding grounds. The range of sounds accords with the sensitivity of the human ear and the low notes can be detected by hydrophones for distances up to 20-30 km. The method of song production is also speculative, but almost certainly is produced by the larynx although in whales this lacks the typical vocal cords of humans. The eastern Australian Humpback Whale stock was exploited only minimally before the 1950s, but it was soon to experience an onslaught that was extreme even by the predatory standards of modern global whaling. Within 10 years the combined effects of the Antarctic fleets and the shore-based whaling at Tangalooma on Moreton Island and at Byron Bay had reduced the stock to less than 5 per cent of the pre-1950 numbers. In 1962 the shore-stations managed a catch of 173 compared with the allotted quota of 810. Since then the stock has shown signs of strong recovery, and is now estimated to be approximately 14,500 individuals. Some researchers suggest this figure exceeds pre-1950 numbers. Most whales return north from the Antarctic feeding grounds in winter and are commonly seen from high vantage points from Point Danger on the Queensland/New South Wales border to the Indian Head/Waddy Point region of Fraser Island between mid-June and early August. They then enter the sheltered waters of the Great Barrier Reef to calve and mate. Humpback Whale migration calendar. Some reach latitudes lower than 15ºS (north of Cairns), but most seem to stay in the central and southern regions of the Reef. During the southern migration from mid-August to mid- November they enter Hervey Bay in large numbers and this event has led to the development of a thriving whale-watching industry in this area and also off Moreton and North Stradbroke Islands. Humpback Whales have become an important focus for conservation. This has resulted from a number of factors, including their previous over-exploitation, large size and relative accessibility to both the public and researchers, their playful behaviour featuring impressive breaching, and lastly by their eerie and complex songs. Further Information Dalton, T. & Isaacs, R., 1992. The Australian Guide to Whale Watching. Weldon Publishing, Sydney. Davie, P.J.F. et al. 2011. Wild Guide to Moreton Bay and Adjacent Coasts. Queensland Museum, Brisbane. Vol. 1, pp. i-xiv, 1-274; Vol. 2, pp. i-x, 1-322. Ryan, M., (Ed.), 2011. Wild Guide to Moreton Bay. Queensland Museum, Brisbane. Author: Robert Paterson & Steve Van Dyck Queensland Museum PO Box 3300, SOUTH BRISBANE QLD 4101 Phone: (07) 3840 7555 http://www.qm.qld.gov.au/ Queensland Humpback whale watching sites (June to October) www.qm.qld.gov.au © The State of Queensland, (Queensland Museum) 2011.