FREQUENTLY ASKED QUESTIONS

Q. How many species of dolphins are there?

A. The taxonomy of whales and dolphins is still subject to change. But in the most common view, the family of dolphins (Delphinidae) consists of 32 different species. Closely related families (the white whales (Monodontidae) and river dolphins (Platanistidae) have 2 resp. 5 species).

Q. What is the largest dolphin?

A. The killer whale (Orcinus orca). Male killer whales can grow up to 9.6 m (31.5 ft).

Q. What is the smallest dolphin species?

A. There is not really one smallest species. The smallest species include: True dolphins (Delphinidae): Tucuxi (Sotalia fluviatilis) - 1.3 to 1.8 m Hector's dolphin (Cephalorhynchus hectori) - 1.2 to 1.5 m Black dolphin (Cephalorhynchus eutropia) - 1.2 to 1.7 m Commerson's dolphin (Cephalorhynchus commersonii) - 1.3 to 1.7 m River dolphins (Platanistidae): Franciscana (Pontoporia blainvillei) - 1.3 to 1.7 m Porpoises (Phocoenidae): Vaquita (Phocoena sinus) - 1.2 to 1.5 m Finless porpoise (Neophocaena phocaenoides) - 1.2 to 1.9 m

Q. What is the difference between dolphins and porpoises?

A. Dolphins and porpoises belong to different whale families. The most obvious differences are: - dolphins have a falcate (hook-shaped) dorsal fin, whereas porpoises have a triangular dorsal fin. - dolphins have conical teeth; the teeth of of porpoises are spatula shaped. - most dolphin species have a distinct beak. Porpoises don't, giving their head a more rounded, blunt shape.

Q. What is a dolphin fish?

A. Dolphins are marine mammals, but there is also a fish species that's often called "dolphin" or "dolphin fish". Its scientific name is Coryphaena hippurus. To avoid confusion with the mammal species its Spanish name "dorado" or its Hawaiian name "mahi mahi" is often used. Because of the confusion between the mammal and the fish species dolphins have in the past erroneously been called porpoises, especially in some US regions, where the fish species is common. In older books you can encounter the name "bottlenose porpoise" for the bottlenose dolphin, for instance. Dolphins and porpoises are however members of different whale families (see 4.5). You can find more information about the dolphin fish, including its common name in other languages, in the FishBase database, online at http://www.fishbase.org/

Q. What are cetaceans?

A. Cetaceans is a collective term for whales, dolphins and porpoises. The name is derived from the scientific (Latin) name of these animals: Cetacea.

Q. Are whales and dolphins endangered?

A. For most species, the answer is probably "No", although it is very difficult to get a good estimate of the size of populations on these water living creatures. A number of species are endangered: the Indus river dolphin, the baiji (there are only about 100 left), the vaquita, the northern right whale and the blue whale. Another group of species is listed as "vulnerable" (which means that they are not in immediate danger of extinction, but also far from safe). These are: the Ganges river dolphin, the boto, the bowhead, the southern right whale, the sei whale, the fin whale and the humpback whale.

Q.  Are dolphins naturally friendly?

A.  Dolphin species vary in their degree of curiosity and interaction with humans.  Individual dolphins vary to the same degree.  Some species are very shy, others will approach humans with great curiosity.  If dolphins have spent time in captivity, they can become very used to people touching them, riding along side of them, etc., but they also can become mildly aggressive; nipping, pushing, etc.
We all heard of the famous stories about dolphin rescues where a human is pushed to the safety of the shore by dolphins.  Bottle-nose dolphins seem to enjoy pushing items.  (Of course we wouldn't hear about the people being pushed out to sea!)

Q.  How deep can a dolphin dive?

A.  The dolphin is capable of diving for up to 20 minutes at 300 meters, this is to be considered as maxima for a bottle-nose dolphin although in some experiments they have dived to about 500 meters.  Usually, bottle-nose dolphins will not dive very deep.

Q.  Do dolphins have a sense of smell?

A.  Dolphins can taste, but have no sense of smell.

Q.  How much do dolphins eat per day?

A.  Bottle-nose dolphins consume approximately 8-15 kgs (15-33 lbs.) per day and Orcas approximately 45 kgs (100 lbs.) per day.

Q.  What do dolphins eat?

A.  Dolphins and porpoises are carnivores - most eat fish and/or squid.  Different habitats mean different diets; each type of dolphin and porpoise specializes in catching prey that lives in their specific ecosystem.

Q.  How long can dolphins go without being in water?

A.  Dolphins and whales out of water have two problems: heat and their own weight.  Large animals have low surface to volume ratios, so it is hard for them to cool themselves.  Also, whales are well insulated (blubber), which is good if they're in the water, but not if they're beached.  It's like having a winter coat on in 70 degree weather, you'd overheat very quickly.  A whale's body isn't designed to support its own weight, it relies on water for support.  The larger whales will die from their own weight if they're beached long enough.

Q.  What are the sounds a dolphin can produce?

A.  All dolphins and whales can produce complex sounds, both for communication among them and for navigation under water. The common dolphin can hear sounds upwards of 150 KHz but generally produce sounds ranging from 1.5 to 11.0 KHZ.  Patterns of sounds can be observed, mostly clicking, moans, whistles, trills, and squeaks.  Males can whistle to get the attention of females or to warn the group of imminent danger (so does man, we are all mammals).

Q.  Why do dolphins make so many sounds?

A.  Whistle like sounds help dolphins keep in contact and communicate with each other as they travel and feed.  Dolphins "echolocate" to find their food or to scan their surroundings.  They direct "clicks" into the water and the  clicks rebound off solid objects (fish, logs, boats) and echo back to the dolphins.  Dolphins listen for the strength of the rebounding clicks to identify what the object is and its distance from them.  All of these clicks and whistles are created in the dolphin's nasal passages just below the blowhole.

Q. How can you tell the difference between a male and a female dolphin?

A. To find this out you have to look underneath the dolphin at it's belly.  If you see a long slit with 2 smaller slits, that's a female:
                   _
 Head  _______  tail
                  _

The smaller slits are the openings for the mammary glands.

For a male, it's more like this:

 Head  ____ _  tail

(No slits to the sides.)

Q. How often do dolphins give birth?

A. Dolphins like bottlenose dolphins give birth about once every 2-4 years. If the calf is healthy, it will nurse for 1-2 years...weaning takes place then but it takes awhile.

Q. How long do dolphins stay pregnant?

A. Dolphins are pregnant for a whole year!!

Q. How intelligent are dolphins?

A. The short answer to this is that we do not know. There is no reliable method to measure intelligence in humans across cultures, so it is not surprising that comparing humans, dolphins, apes, dogs, etc. is impossible. There are some indications of their potential: they are fast learners and can generalize (which is also true of pigs, BTW). Also they can learn to understand complicated language-like commands (which is also true of the great apes).

Q. Is a marine mammal trainer the same thing as a marine biologist?

A. We often hear people say, "I want to be a marine biologist and train dolphins". While it is true that some marine biologists do train dolphins and many trainers have degrees in biology, the two job descriptions are really quite different. Many folks mistakenly lump marine mammal trainers, marine biologists and oceanographers into one homogenous group. Oceanographers primarily study the physical nature of the world’s oceans, for example, their chemical, geological, and atmospheric aspects. A marine biologist is generally someone who studies life in the seas and oceans. They may specialize in such areas as anatomy, physiology, behavior or ecology. The subjects of their investigations may range from microscopic single celled organisms to 150 ton blue whales. Proportionately very few of these scientists work hands on with or train living marine mammal species. A good marine mammal trainer may study and utilize knowledge from all of these fields (and more), but each of these careers are really part of their own specialized discipline.

Q. What does a marine mammal trainer really do?

A. One obvious answer to this question is that we train dolphins, whales, seals, sea lions, walruses and other marine mammals using a system of positive reinforcement called "operant conditioning". Behaviors are taught to help educate and entertain people through our shows, demonstrations and interactive programs. However, this is just one small part of the job. Our primary responsibility is always to maintain and enhance the health and well-being of the animals in our care. To achieve this goal marine mammal trainers must understand and work hard to ensure that their animals are provided with the highest quality food, aquatic environments, structural habitats, social and behavioral opportunities and medical care. Training can be an extremely powerful tool in meeting these goals. For example, animals are routinely taught "husbandry" or "veterinary" behaviors that allow us to monitor and track their health status and even treat them when necessary with the least amount of delay or stress. Some of these incredibly useful behaviors include the voluntary collection of blood, gastric, urine and fecal samples; physical, X-ray, ultrasonic and dental exams; and the administration of medicines, replacement fluids and even physical therapy. In just the last few years, veterinary procedures that may have required physical restraint of an animal can easily and safely be trained to allow routine collections without restraint or danger to the animals or the staff. Our veterinarians are able to get much more accurate pictures of our animals’ health status before they show any outward signs of illness. (This is extremely important as marine mammals are notoriously good at hiding disease. Many scientists believe that this ability to mask illness or weakness has evolved as an important survival mechanism to avoid being targeted by predators in the wild.) Training also provides a great tool for facilitating the movement and relocation of animals from one habitat to another, thereby helping to manage compatible social groups. In addition, many independent researchers now agree with what trainers have known for a long time, that training provides valuable mental and physical stimulation, as a form of environmental enrichment, which is important for long-term health and well-being. As a result of all this training and proactive health management, our animals are living much longer and healthier lives than ever before. Many of our animals are outliving their counterparts in the wild.