Look and Listen for Humpback Whales
by Esta Lee Albright
Adapted from Soundings, April 2002|
March brought our first repeated Humpback Whale sightings of the spring. On one whale watch trip northwest of Pt Pinos, among a half dozen Gray Whales and several hundred Pacific White-sided Dolphins, there was a swish of a whale's tail fluke. "Whoa!" I said. "That's something we don't see often .... a Gray Whale slapping the water with tail flukes....... Whoops! The reason that looked odd for a Gray Whale is because that's really a Humpback Whale!" |
 Curious humpback whale investigating motionless whale watch boat. |
The next question about Humpbacks is usually, "Are they on their way to Hawaii?" Television programs filmed in the clear waters of Hawaii, when Humpbacks are there in the winter, lead people to associate Pacific Humpbacks with Hawaii, and not Monterey.
The truth is that there are rather distinct populations of Humpbacks in most of the world's oceans. As with other species of baleen whales, their annual cycle puts them in cold, nutrient-rich waters to feed and the warm tropics to breed. There is occasional crossover of individual whales from one population to another, but scientists studying the various groups name feeding grounds and breeding grounds for the various populations. They try to figure out which whale goes where by using the familiar ID marks under flukes, profiles of dorsal fins, sloughed skin for DNA analysis, and even tagging.
The North Pacific Humpbacks use about 4 breeding areas. Those breeding in Hawaii feed in Alaska. Humpbacks feeding here in Monterey in summer and fall usually winter south of Baja or west of Central America. Humpbacks breeding near Japan, Philippines, China, the Mariana and Marshall Islands, may feed in the Bering Sea or northwestern Pacific. There is a small group wintering south of Baja, near an island called Socorro, that goes all the way to Alaska to feed. According to John Calambokidis of Cascadia Research, at a recent ACS meeting, the Socorro Humpbacks go past Monterey early. Perhaps we're seeing them now.
The most well-studied population of Humpbacks feeds in the North Atlantic, from Maine to Norway, and breeds mostly in the Caribbean. Historically, a few of these bred in the Cape Verde Islands. Many that feed in the Gulf of Maine are recorded and named, and a female named "Salt" has been a celebrity with New England whale watchers for 25 years.
In the southern hemisphere, Humpbacks feed in Antarctic waters and head toward the equator to breed. It's possible some even cross the equator and use waters west of Central America in their winter (which is our summer). One humpback identified in both the Antarctic and waters off Colombia now holds the record for longest migration by a mammal.
There is a breeding population of Humpbacks around Madagascar, western Africa, West Australia, Coral Sea, west of South America, east of South America. Tonga, in the South Pacific, offers whale watching cruises among Humpbacks breeding there. These South Pacific whales often have much more white coloration on their undersides.
A different population is found in the northern Indian Ocean and the Arabian Sea, eastward around India and Sri Lanka. These seem to stay in the same waters year round.
Humpbacks are still considered endangered species. Even though some populations seem to be recovering nicely, the number still must overcome the fact that whalers killed about 95 per cent of the world's Humpbacks before the 1960s. Under the "subsistence whaling" by indigenous peoples, Bequia whalers kill perhaps two per year and are under much pressure from Japan to support a return to commercial whaling.
The catalog of ID marks for "our" Humpbacks is held by Cascadia Research. There is an estimate of 900+ Humpbacks feeding off California, Oregon and occasionally Washington. The opportunistic Humpbacks gulp-feed on schools of little fish or on krill. They move around with the food supply. Last fall numbers were reported far offshore of San Mateo County, not here.During the past two years, the month of May has brought huge schools of small fish into the bay and nearshore waters, with humpbacks feeding, leaping, flipper slapping and generally becoming a graceful thrill to watchers both on boats and the shoreline.
Humpbacks are famous for their songs, which are vocalizations by males on the breeding grounds. They seem to be tied to mating display: intersexual for males to attract females; intrasexual, as a male dominance display; or both. Individuals slowly change the structure of their songs. Whales of an area pay attention to and copy each other so that all whales of a population sing essentially the same song. (Frankel p.1131) It is a joy to read descriptions of the song by Roger Payne, one of the discoverers of Humpback songs.
|
"These songs are much longer than birdsongs and can last up to thirty minutes, though fifteen is nearer the norm. They are divided into repeating phrases called themes. When the phrase is heard to change (usually after a few minutes), it heralds the start of a new theme. Songs contain from two to nine themes and are strung together without pauses so that a long singing session is an exuberant, uninterrupted river of sound that can flow on for twenty-four hours or longer. The pace of the song is very grand and extended and appears to me to be set by the slow rhythm of ocean swells...." (Payne p.144) |
|
"Humpbacks produce the feeding call while they are maneuvering underwater. The call has been suggested to either coordinate the movements of the whales or manipulate prey. Recent experiments played back feeding calls to herring, which responded by fleeing from the call. These observations suggest that prey manipulation is the most likely function of this call. [It] is a nearly constant frequency tone lasting between 5 and 10 sec. It has been compared to the sound of a train whistle. It is often repeated in a series of calls, and there is sometimes a shift of frequency at the end of the series of calls. There is variation in the frequency of the call, but most are between 500 and 550 Hz." (Frankel p.1132) |
Sources:
Clapham, Phillip J. "Humpback Whale, Megaptera novaeangliae." in Encyclopedia of Marine Mammals. Academic Press, 2002.
Frankel, Adam S. "Sound Production." in Encyclopedia of Marine Mammals, Academic Press, 2002.
Payne, Roger. Among Whales. Scribners, 1995.
Rice, Dale W. Marine Mammals of the World; Systematics and Distribution. The Society for Marine Mammalogy, Special Pub. No. 4, 1998.
- Hear some short excerpts of Humpback Whale Songs.
- Find out more about Humpback Whales.
|| Glossary || Return to ACS Monterey Bay home page ||
Photos by Esta Lee Albright.Last updated April 30, 2002.