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Dr. Colleen Reichmuth (above left) directs the Pinniped Cognition and Sensory Systems Laboratory at the University of California Santa Cruz. She has a B.Sc. in Biology, a M.Sc. in Marine Science, and a Ph.D. in Ocean Sciences, and she has worked with marine mammals since 1990, conducting research in the areas of comparative cognition, bioacoustics, and behavioral ecology. Reichmuth's laboratory in Santa Cruz is home to a California sea lion, a harbor seal, a northern elephant seal, and a southern sea otter, all of whom are trained to work closely with researchers to find out more about how they gather, process, and use information from the world around them. Reichmuth also conducts research with captive walruses at Six Flags Discovery Kingdom (see How to Speak Walrus), sea lions undergoing rehabilitation at The Marine Mammal Center, and field studies of pinniped behavior at Aņo Nuevo State Reserve near Santa Cruz.
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On July 27, 2009, Colleen Reichmuth and Kristy Lindemann-Biolsi answered selected viewer questions about the cognitive and communication abilities of pinnipeds. (See their first names below each answer to learn who answered what.) Please note we are no longer accepting questions, but see How to Speak Walrus and our Links & Books section for more information. Q: I've heard that all emotions found in humans (and varying shades of consciousness) have been found in non-human animals. But can animals actually engage in sophisticated communication (language)? A: Great question, and one that is an area of active research. I want to start by distinguishing between communication and language. All animals communicate, however the depth to which they do this varies from species to species, while language is a specialized form of communication that has only been found in humans. In terms of communication, consider the male peacock with his impressive tail. Having such a tail is a signal to a female that attracts her to him. However, the male peacock is not deliberately sending a signal—the signal is his appearance, but this does communicate something to the female. We can also look at communication with a more common animal, the domestic dog. Growling and raising its tail communicates a very different meaning than cowering and tucking its tail under. Interestingly, scientists have even discovered communication systems in some insects. For example, honeybees engage in what has been termed the "waggle dance." When an individual bee locates a food source, it returns to the hive and performs a dance involving shaking its abdomen and moving in a figure eight-like pattern. The intensity and type of shaking as well as the direction of the dance informs the other bees in the hive of the location of the food source. Overall, communication systems—whether the communication by an individual is intentional or not—can be found among all animals. More sophisticated systems of communication have been found in some nonhuman animal species, including an African grey parrot, apes, and some marine mammals. These abilities are often termed "language-like." A parrot, chimpanzee, dolphin, or sea lion may appear to be communicating using language as we humans do, but after closer examination and experimentation, researchers have found that though the performances of these animals are impressive, they do not appear to use symbols interchangeably to represent objects in their environment in the same way that humans can. Also, humans are language machines! A two-year-old child can learn up to 40 new words a week, surpassing that of the most experienced "language"-trained animals. So far, what research has taught us is that some species have some of the underlying mechanisms that are necessary for language to occur, but humans are the only species to have fully developed language. Kristy Q: Have studies been carried out with pinnipeds on self-awareness, the ability to recognize themselves in mirrors (for instance), similar to those done with chimps, etc.? What were the results? A: Self-awareness is a tricky subject to study. Studies of self-awareness in animals often do involve "mirror tests" to determine if individuals can recognize their own reflections, and some scientists believe that positive results in these experiments indicate that animals have a "self-concept" or what has been described as the potential to imagine oneself as one is viewed by others. People begin to show an understanding of their mirror images at around 18 months of age. As you may know, animal studies using mirrors often involve placing a mark on an individual's body, and then observing the individual in the presence of a mirror to see if the reflected image is used to guide an animal's attention to the mark on its own body. Some nonhuman primates, dolphins, elephants, and at least one type of bird have passed such tests, while animals like dogs and cats have not. While pinnipeds have not been expressly tested using the marking method (to my knowledge at least), like other carnivores, sea lions tend to initially respond to their reflected images as they would to social stimuli (making threatening postures, zooming towards or vocalizing underwater at the mirror). My colleague, Ron Schusterman (who was featured in the program), conducted these mirror experiments over 40 years ago and found that sea lions lost interest in mirrors with repeated exposures to them rather than learning about how to use them to gain information about their own bodies. Interestingly, Ron has also described to me observations of "sneaky" pinnipeds that seem to hide behind barriers or take the posture of females while trespassing on a dominant animal's harem or territory. These anecdotal observations may suggest some level of self-awareness that will require more research to sort out. Colleen Q: I saw where Rio was taught that a set of letters went together and associated them with a sound, but have you ever tested her with a figure that is clearly a letter and not a number (e.g., X) to see if she can associate the sound with that figure? A: To answer your question I want to first point out that to Rio "letters" and "numbers" are arbitrary black-and-white patterns. She had to learn over time to group these stimuli into these two categories. Therefore, presenting her with an "X" as a "letter" would be no different that presenting her with a "12" as a "letter." To her these would both be novel stimuli that she would have to learn to associate into the appropriate category. The "letters" and "numbers" are arbitrary, and therefore there are no iconic or perceptual reasons to group them together. In fact, when designing Rio's stimuli we have made sure that she could not group them together based on any perceptual features. Your question actually seems to be asking about stimulus generalization. For example, if Rio is taught that the sound "Ring" is related to a circle, what would she do if presented with another circle or a "circle-like" stimulus instead? Would Rio only relate the sound to the individual circle she was trained with, or could she generalize to other, novel stimuli that are perceptually similar and make the correct choice on the first try? While we did not carry out this exact experiment with Rio's auditory stimuli, it has been well-documented that many animals, including California sea lions, are capable of such performances. Animals have been able to generalize many perceptual features (such as color, size, shape, etc.) of stimuli and respond appropriately on the very first try! Kristy Q: Do the pinnipeds you work with vary in terms of their ability and their interest in doing the work you put them to? That is, are they like students in a classroom: a mix of teacher's pets and slouchers? Also, have you ever had any mishaps with any of them, where they accidentally injure you just by being big and boisterous (especially the walruses)? Thanks. A: I love your first question! Short answer: YES. Slightly longer answer: We see some general differences in behavior and performance that vary by family and species. It's worth pointing out that the three families of pinnipeds (the sea lions and fur seals, the "true" seals, and the walruses) are very distinct (separated in evolutionary time by anywhere from 8 to almost 30 million years!). And, of course, each species has its own behavioral habits. What I find really interesting is how different animals of the same species are. Like people, no two are alike. Even youngsters raised in identical environments can have very different temperaments. In How to Speak Walrus, walrus trainer Leah Coombs describes the different personalities of our captive walruses, who were all raised together from the time they were stranded calves. In my own experiences training and testing marine mammals, I have met my share of overachievers and slouchers. One thing that I have discovered is that individual animals learn better under certain conditions. Like students in a classroom, part of the challenge lies in understanding what motivates an animal and figuring out how to keep their interest and attention on the task at hand. Once you get that sorted out, you can start to find out more about what they are capable of. As to the second part of your question, short answer: YES. Your question gives me a chance to point out that animals like walruses are not only big and boisterous, they can be aggressive and dangerous. In all their flippery cuteness, it can be easy to forget that pinnipeds are 1) carnivores and not cetaceans, and 2) are wild and not domesticated animals. Like terrestrial carnivores (bears, wolves, lions, etc.), pinnipeds can and will respond aggressively in certain situations. Luckily, we have a lot of positive tools that we can use to keep our interactions with the animals safe and fun for the humans and for the animals. I've had my share of mishaps (some funnier than others), but I try to never forget that I am working with potentially dangerous animals. Colleen Q: How long do pinnipeds live? A: The lifespan of a pinniped depends on the species. In general, seals may live to be 25-30 years old, but seals such as the elephant seal have a much shorter life expectancy—they usually live 10-15 years. Sea lions live about 25-30 years, and walruses may survive longer than 30 years! Also, it's important to remember that life expectancies will be different in the wild versus captivity. Usually animals, including pinnipeds, live longer lives in captivity because their life is a bit easier and less stressful (they don't have to hunt for their food or avoid predators!), and they have a veterinarian to give them routine check-ups and to give them medicine if they get sick. Kristy Q: Do you read papers and otherwise keep up with studies by researchers working with other so-called "intelligent" animals like parrots, for instance? Or is comparing results about marine mammal intelligence with that of, say, birds comparing apples and oranges? If you do compare and contrast, what have you found of interest, either striking similarities, or striking differences, across species? Thank you, and keep up the fascinating work. A: Absolutely! A major part of my job is keeping on top of the current research, not just with pinnipeds but with other animal species, too—including humans! Comparing various areas of animal intelligence across species is a really interesting field, and there are a surprising number of similarities. Many animals with similar environmental pressures, such as complex social structures or hunting/foraging strategies, may have similar cognitive abilities that help them to succeed in their environment. In general, I would argue that there are more similarities across species than differences! Therefore, learning about one species can teach us something about another. Having said that, I must also mention that when comparing animal intelligence we have to remember that different animals live in very different environments and are therefore specialized for different tasks. This leads to different problem-solving abilities. So while on some levels animals are similar (including humans), we should not take that for granted and must also embrace the differences! Did you know that birds can see more of the color spectrum than we can, and many animals can hear lower and higher pitch sounds than we can? To answer your other question: One striking difference between species is the use (or lack of use) of pointing and eye gaze. Pointing and eye gaze for communication are two things that humans use frequently and start using at a very young age (before verbal language develops). However, despite many other similarities, including our genetic relatedness, chimpanzees seem to be poor at utilizing eye gaze and pointing—even after extensive training. Perhaps even more interestingly, dogs seem to be excellent at this! These differences are most likely due to evolutionary pressures on this form of communication, but it is striking to me because of how similar chimps and humans are as compared to dogs and humans. Kristy Q: How do walruses make that knocking sound? And what would that sound be used for in the wild? Why did it evolve? A: Hi Sarah, clever question! As you heard in the program, walruses can produce a pretty weird knocking noise. [Hear it in How to Speak Walrus.] It turns out that this sound is produced by males, who mainly make this noise underwater during the breeding season. We are not certain about how the sound is produced or why, but we are working on both of these questions right now. One of the reasons we know so little about communication among walruses is because they breed in the high Arctic, in the dark winter months, in areas typically comprised of unstable pack ice. As a result, there are only a few known recordings of wild walruses. Some fearless Canadian researchers have successfully recorded male Pacific walruses during the breeding season and described their underwater sounds as songs with unusual components and complexity. In addition to REALLY loud knocking noises, these songs include metallic gong-like sounds, and occasionally, whistles produced at the surface. These songs are also REALLY long, sometimes lasting days on end. You can actually hear some of these bizarre walrus songs for yourself by visiting the Macaulay Library of Natural Sounds online at http://macaulaylibrary.org/index.do, searching for walrus, and listening to the recordings made by Becky Sjare. (Try it, they'll knock your socks off!) Based on these recordings, it seems clear that the acoustic displays of male walruses have a reproductive function, but we are not yet sure if that function is related to competition among males or to gain the favor of females. By studying knocking in our captive male walrus Sivuqaq, we hope to get some insight into a lot of interesting questions, including how the sounds are produced in air and underwater, what their characteristics are (level, frequency, repetition rate, etc.), how far they might travel underwater, how the sounds are sequenced into complex songs, how these displays change with age and season, and to what extent they are learned vs. innate. One last comment about how these crazy knocking noises are produced: While nobody knows for sure how these sounds are made in the body, some investigators have suggested they might be produced by clacking the teeth together or popping the tongue against the roof of the mouth. In air, the sounds feel as if they are coming through the forehead. Underwater, no air is expelled when the knocking noises are produced. Check in with me sometime in the future to see if we have figured this mystery out! Colleen Q: Where can I read more about your research? I am very interested. Also, I give presentations as a volunteer to school kids and the public about marine mammals at the Pacific Marine Mammal Center and would like to share some basics about their intelligence. Thank you. A: Hi Kathy. I've been to your rehabilitation center many times and must thank you for the wonderful work that you and your colleagues do there! Please visit our website for more information about our research program, including videos and articles about our work. There is an article posted on the site called "Problem Solving and Memory" (2002) that I think you would find helpful. Just click on www.pinnipedlab.org. Colleen Q: Loved the program. Your work looks like a hoot (and here I am stuck in an office all day). My question is: What's next in terms of your research? What question or questions would you most like to answer with your pinniped subjects? Thank you. A: Glad you enjoyed the program! Currently we are using the arbitrary stimuli (ring sound, siren sound, "letters", "numbers", etc.) that were featured in the segment you saw. In the future we plan to use naturalistic stimuli such as sea lion vocalizations, specifically pup calls. In the wild, these animals are excellent at individual recognition—mothers must recognize their pups and pups their mother. This is critical for survival. The nursing period is six to eight months for most sea lions and during this time mothers nurse their pups for two to three days and then go out to sea to forage for five to seven days. During their foraging trips, they leave their pup on the rookery with hundreds of other sea lions. When the mother returns, she and her pup must reunite on the crowded rookery or the pup will not be able to nurse and therefore not survive. One of the first steps of a successful reunion is that the mother calls to her pup, and when the pup hears her it calls back. Therefore, vocalizations and categorizing individuals based on their vocalizations are critical, and we plan to further investigate this process in the laboratory. Kristy Q: I was amazed how focused Rio seems to be when doing the work. Kinda scary really, like you wouldn't want her to be doing that to you! Is that behavior peculiar to her, or is there something about sea lions that makes them behave like that under certain conditions? In the wild, do they get that focused when hunting, for example? A: Rio is a special animal, and if there is one thing she hates, it's making mistakes! She is very focused while performing problem-solving tasks and other kinds of behavioral experiments. This kind of "work" is both challenging and rewarding for an animal like Rio. While we tend to think of Rio as being particularly sharp and highly motivated, it is true that sea lions in general are pretty good at performing behavioral tasks in order to get what they want. Whether in the wild or in captivity, they seem to show a high degree of behavioral flexibility. This is probably why we see California sea lions as trained performers in circuses, zoos, and aquariums. This same tendency for adapting to changing conditions and learning about how to exploit their environment can drive people crazy, as seen in conflicts surrounding sea lions learning to steal salmon from fish ladders and fish farms and to live in areas of high human disturbance, like San Francisco's Pier 39. Colleen Q: I worked with a ranger service dog for about 10 years. Now I breed and train schutzhunds. And I'm trained as a biologist and to be a keen observer. I want to know more about what you mentioned as the remarkable similarity between intelligent mammals. I understand we are genetically quite close. Tell me where to read more, particularly what you found in your search of the literature and/or wrote yourselves. A: I hope that some of the other questions discussed here have given you some more information on animal intelligence, but, of course, there is plenty more information out there! If you are interested in our lab's work, you can visit our website: www.pinnipedlab.org On this website you will find information about the current research projects, such as the ones featured in the segment with the walruses and Rio. You will also find a link to all of our lab's publications. The site will give you access to the full articles—all you have to do is click on them! As for other references, I would recommend: Cognition, Evolution, and Behavior Comparative Cognition: Experimental Explorations of Animal Intelligence Kristy Q: I just read an article in the New York Times Magazine about whales, and how some scientists believe whale strandings might have something to do with the Navy's sonar or other loud noises we introduce into their environment. Having worked extensively with marine mammals, what's your take on this? Have you found the animals you work with are extremely sensitive to sound? If so, does that sensitivity differ depending on whether they're in or above water? Thanks. Horrible to think our engines, sonar, etc. may be injuring these magnificent creatures. Q: Since pinnipeds, cetaceans, and other marine mammals communicate through water as well as air and water has different properties than air, how far away can they be and still hear each other? There has been at least one study of whale song transmission as changes that occurred in a season are learned by other members of the species. In order for that to happen, whales must be communicating with each other as the message is encoded, transmitted, received, and decoded just as humans do when we speak and listen to each other. Elephants do so by using very low-frequency sound and so do giraffes in Africa. Do we even hear all of whale song since we only hear a limited range of frequencies? A: These last two questions from Jackie and Roger are a little beyond the scope of this program but raise some great points about how marine mammals, including pinnipeds, use and are affected by sound. It turns out that a good chunk of the research going on in our lab deals directly with these important issues. In addition to our research on cognition and communication, we study the sensory systems of pinnipeds with an emphasis on acoustics. Since our animals are amphibious, we study their hearing both above and below the water's surface, and we do a variety of different experiments to address evolutionary, ecological, and anthropogenic questions about sound. To find out more about this work, I encourage you to visit our website: www.pinnipedlab.org Colleen This Q&A session has been a lot of fun for us. We wanted to thank everyone who participated for your great questions and for your enthusiasm for these fascinating animals. We also wanted to thank our friends at NOVA scienceNOW for helping us to share our research with all of you in such interesting ways. Best fishes! |
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© | Created June 2009 |
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