Harkomal, a fifth-grader currently participating in our Online Classroom Connection program, submitted the following ten questions. I was able to pull in DCP researcher Justin Gregg, Ph.D to help answer some too!
1. Why do dolphins have 3 stomachs?
Some dolphin species have two stomachs, but most do indeed have three. The first of the three stomach acts as a storage unit – it holds the food until the other stomachs are ready for digestion to occur. Using this method, a dolphin can quickly gobble up as much food as it wants, and then, when it has a free second, allow the food to enter the second stomach. The second stomach is where all the action happens, and functions a lot like the human stomach, with enzymes and acids breaking down the food. The third stomach acts as a kind of waiting area for the digested food before it is dumped into the small intestine.
2. How long does it take to become a marine biologist?
This can really depend on what kind of work you want to do as a marine biologist. You can do a lot of work with a Bachelor’s degree (4-years) and even more work with a Master’s. If you want to teach at a college or be a senior scientist managing research and other scientists you may also need a Ph.D.
3. What do you do to become one?
Every successful marine biologist has to start with a strong interest for the marine (or freshwater) environment. You have to be interested in the life there: the plants, the animals, everything. I (Kel) was always drawn to my science classes and by the time I was in college I decided to get a degree in Environmental Studies. I thought this would give me a broad background in most things environment-related, not just the oceans, which it did. I took classes like geology, botany and zoology, but also took social classes to learn more about how people all over the world interact with their environment. While in college, I started interning with DCP and really like the field work. So, I decided to get my Master’s (which took me almost 3 years). I now get to manage DCP’s research in Bimini, The Bahamas and contribute to our various education programs. For me, it’s the perfect balance of traditional science and education.
4. What do prehistoric dolphins look like?
The earliest ancestors of dolphins were land mammals that probably looked a lot like large rodents. As these species slowly evolved into ocean dwelling animals, they probably started to look like seals and sea lions – with sleek bodies, but still retaining limbs. Over time, as new species spent more and more time in the water – eventually living their permanently – their limbs evolved into the flukes and flippers that we now recognize in modern dolphin species. Also, the nose of the ancestors of dolphins moved to the top of their heads, with the blowhole eventually evolving over it, and the nostrils becoming the organs in the dolphin’s head that now produce their vocalizations.
5. How do dolphins use echolocation?
DCP has produced a podcast episode with all sorts of lovely detail on how dolphins use echolocation. You can check it out at this link: http://www.dolphincommunicationproject.org/index.php?option=com_content&task=view&id=1111&Itemid=263
6. How do dolphins fend off predators?
Their primary means of fending them of is to avoid them. Dolphins tend to leave the area when large sharks (their natural predator) show up. But when they are attacked, dolphins sometimes attack sharks by ramming them with their beaks. Sometimes dolphin groups will gang up on sharks in order to chase them off. Dolphins have “safety in numbers” on their side; they usually stay in groups so many dolphins can be on the lookout for predators.
7. What is the rarest species of dolphin in the world?
There are two possible answers for this one. First, the Baiji, otherwise known as the Yangtzee river dolphin, was declared ‘functionally extinct’ a few years ago. Scientists went on an expedition to look for any sign of a living Baiji, but didn’t find a single one. This led them to the conclusion that even if there are any left, their population is so small that they are destined to go extinct. It’s still possible there is one or two Baiji alive, but scientists are not really sure. If they truly are extinct, then the next rarest dolphin is Maui’s dolphin – which lives in the waters around New Zealand. There are probably less than 100 of these little guys left.
8. Do dolphins fight for a mate?
Many species of dolphins do indeed fight for access to females for mating. Dolphin mating happens very quickly, and males and females do not stay together for life – or even very long after mating happens. So, males spend a lot of time competing in order to be the one to get that brief chance to mate with the females. Sometimes males form groups in order to fight off other male dolphin groups for access to females. A lot of male dolphins are covered in rake marks (tooth scars) from fights with other males. Usually these fights are very brief, and do not result in serious injury.
9. What is your favourite type of fish?
Ah, a fish question to dolphin researchers! My (Kel) favorite fish, technically speaking, is probably the spotted eagle ray. Spotted eagle rays are relatively closely related to sharks and are common in the waters around Bimini. Sometimes I like to sit and watch the harbor – if I’m lucky I see a spotted eagle ray leaping completely out of the water! As far as other fish go, I definitely have a sweet spot for puffers. Once, I was able to observe dozens of them huddled in the roots of Bimini’s mangroves. They were amazing!
10. When did you start working with dolphins?
I (Kel) began officially working with dolphins in 2003 as part of a summer internship with DCP – and I’ve been hooked ever since. But, even as a young student I was always interested in marine mammals. I used to ride my bike to the library and photocopy the whale and dolphin books!
Thanks for your great questions and for sharing so much dolphin information with your class. If any of our answers have led you to new questions, write them down and you can ask them when we chat via Skype!