Cetacean Society International

Working for whales, dolphins and porpoises worldwide

CSI Photo Gallery

Bryde's Whale

(Balaenoptera edeni)

Bryde's whales are found in all oceans with warm, productive, tropical waters where surface sea temperatures are above 20 degrees C, as here in the Gulf of California. Most stay between 30°N and 30°S, and in some areas they are the most common large whale species. Up to 50 feet (15.5 m) long, they can easily be confused with sei and finback whales. (Photo courtesy Alisa Schulman-Janiger)
As this whale exhales the characteristically high but thin blow of the Bryde's whale, you can see the three ridges on the upper jaw, ahead of the blowhole. These are the most reliable field marks whale watchers use to be sure of what they're seeing. But of course, just to be confusing, some Bryde's whales have been reported without the ridges. No one knows what purpose the ridges serve, but why do they have to have a purpose? (Photo courtesy Alisa Schulman-Janiger)
Bryde's whales take four to seven breaths, each with a short, shallow dive, before diving deeper for two to eight minutes. Of course this pattern varies considerably, depending on whether they are traveling, foraging, socializing, or resting. While their normal travel may not show much of their body above the surface, Bryde's whales also are known to breach, especially after periods of high activity. One whale near Japan breached over 70 times in a row. Why? (Photo courtesy Alisa Schulman-Janiger)
Bryde's whales are very maneuverable for their 12-20 ton mass. Sometimes they seem to behave like very large dolphins as they charge into prey concentrations, usually small schooling fish and some species of krill. Like all rorqual whales, they are built for efficient speed and can move slowly with little effort. They may rarely come to a complete stop, even as they rest. We suppose that, like dolphins, baleen whales must consciously take breaths, so they never sleep as we do. Instead, one half of their brain always is awake enough to manage breathing, so the whale also can swim and remain alert. (Photo courtesy Mark Fischer)
Like other rorqual whales, they somehow find and then lunge into concentrations of prey, with enormous mouths gaping, taking tons of water into a special sack linked with their tongue that expands all the way to their bellies. Squeezing out the water through their baleen leaves thousands of fish to be swallowed through a very narrow throat. How many tiny fish does it take to keep a 20-ton whale alive and well? How does the whale find enough food, as here in the Sea of Cortez? We can guess that diving whales may see patches of prey silhouetted against the surface, or hear them swimming, or taste their trails in the water, or hear other whales feeding. And maybe the whales just dive and hope to find prey in their path, because enormous numbers of creatures move down as the day brightens and up as the day darkens. (Photo courtesy Mark Fischer)
See the small ribbon hanging from this whale's dorsal fin tip? This is a creature that literally hangs on for dear life, catching food that passes by as the whale swims. But first the creature had to catch this whale! It was floating in its juvenile form as part of the enormous mass of plankton drifting in some ocean areas, when this whale happened to pass by. It had only one very brief instant to react, and used special appendages to grab and hold on to the whale's skin until a more secure fastener could be made. There are many creatures, like barnacles, adapted to life on whales. To them a whale is their whole world. Many will die or fall off if the whale swims into cooler waters. (Photo courtesy Alisa Schulman-Janiger)
This whale may be the only one we can see, but he knows that he's part of a large group spread out over many miles. Like other large whales, Bryde's whales use low frequency calls to reach each other over long distances, allowing individuals to keep in contact. These calls may be used for breeding and simple social cohesion, and feeding sounds may alert other whales to where food can be found. Better recording and sampling equipment finally are showing scientists that these sounds can be very complex, and soon we may understand what to the Bryde's whale is all the language they need. Do they intentionally tell each other where the best food is, or just make a lot of noise eating? What do they say about the increasing din of human noises in the oceans? (Photo courtesy Alisa Schulman-Janiger)
Some Bryde's whales populations may mate and calve at any time of year, for example near South Africa, probably because food is available all year in fairly warm waters. Perhaps they don't need to migrate to give birth in warmer but less productive waters, as with other Bryde's whales and most other baleen whales. If they rarely stop they would travel thousands of miles in a year, so what we call migrating may be a whale going somewhere we notice. To the whales they are always going somewhere. As they learn where food and other whales may be found, they must develop a mental map of where they are and where they want to go. But how do they find their way? This whale may hear the surf on that distant shore, or the echoes of the rising bottom, and such cues may help. (Photo courtesy Alisa Schulman-Janiger)
There is an inshore form of Bryde's whale that seems to prefer staying in one area, and an offshore form that may migrate, but no Bryde's whale populations are known to migrate long distances. There is also a pygmy or dwarf form in the Pacific Ocean. Genetically these variations seem more closely related to sei whales than each other. Some scientists believe that, because of genetic differences between populations isolated over time, Bryde's whale may be accepted as at least three species soon. The whales won't care or notice, and genetically defining species that all look alike doesn't help whale watchers very much. (Photo courtesy Alisa Schulman-Janiger)