Deep Thinkers: Inside the Minds of Whales, Dolphins, and Porpoises

by Janet Mann (Editor)

Humans aside, dolphins, whales, and porpoises are often considered to be the smartest creatures on Earth. Science and nature buffs are drawn to stories of their use of tools, their self-recognition, their beautiful and complex songs, and their intricate societies. But how do we know what we know, and what does it mean? In Deep Thinkers , renowned cetacean biologist Janet Mann gathers a gam of the world’s leading whale and dolphin researchers—including Luke Rendell, Hal Whitehead, and many more—to illuminate these vital questions, exploring the astounding capacities of cetacean brains.

Diving into our current understanding of and dynamic research on dolphin and whale cognition, communication, and culture, Deep Thinkers reveals how incredibly sophisticated these mammals are—and how much we can learn about other animal minds by studying cetacean behavior. Through a combination of fascinating text and more than 150 beautiful and informative illustrations, chapters compare the intelligence markers of cetaceans with those of birds, bats, and primates, asking how we might properly define intelligence in nonhumans. As all-encompassing and profound as the seas in which these deep cetacean cultures have evolved, Deep Thinkers is an awesome and inspiring journey into the fathoms—a reminder of what we gain through their close study, and of what we lose when the great minds of the sea disappear.

Genres: Science, Nonfiction, Animals, Nature, Biology

192 pages, Hardcover

Published October 11, 2017

Reviews

[Pam]

I’m finished with what I’m going to read. The book and I part company. Too dry and too academic for me to continue.

[Pamela · Rating 5 out of 5]

There's no other book out there like this one--a very well-written, wide-ranging, and accessible book about cetacean intelligence. The authors are all experts in the field that make the science easy to understand without undercutting the complexity of the subject. The photos--especially the spreads opening each chapter--are stunning. I particularly appreciated the lucid description of particular experiments. All-around excellent and a must-have for anyone interested in whales and dolphins.

[UChicagoLaw]

"For my book on animal rights I have been reading a lot of scientific books on animal cognition. Of these, a real masterpiece is Hal Whitehead and Luke Rendell's The Cultural Lives of Whales and Dolphins, a rigorous account of learning in whales and dolphins, arguing convincingly that quite a lot of it is not simply genetic, but cultural, imparted by imitation and teaching from the social group. Their conclusions have ethical importance: among other things, keeping orcas and dolphins in marine pens deprives them not just of free movement and society, but of all chance to become themselves, fully what they are. People should pair this with the more popular collection of essays edited by Janet Mann: Deep Thinkers: Inside the Minds of Whales, Dolphins, and Porpoises, with essays by leading scientists and glorious photography. It's so much fun to learn about these mysterious animal relatives, whose lives challenge us all to think, and live, better."

- Martha C. Nussbaum, Ernst Freund Distinguished Service Professor of Law and Ethics

[AvianBuddha · Rating 5 out of 5]

I will summarize a few interesting points from Deep Thinkers: Inside the Minds of Whales, Dolphins, and Porpoises for my reference and share my thoughts on the book. I read this book because I love how inquisitive, highly intelligent, and sociable dolphins are, and I am also saddened by the environmental catastrophes they have suffered.

Cetaceans are divided into two groups: odontocetes (toothed whales, 75 species) and mysticetes (baleen whales, 14 species) (10). Mysticetes are relatively solitary, whereas odontocetes form stable associative groups with complex communication networks, dynamic alliances, and more. Mysticetes share songs across a population, much like birds, whereas odontocetes use group-specific and individual-specific calls that are important for identifying social units. Mysticetes also reach maturity faster than odontocetes. Odontocetes have larger brains on average, scaled to expected body mass (EQ), compared to mysticetes. Cetaceans have no sense of smell, and their "nose" has migrated to the top of their head for breathing (14). Cetaceans descend from a hoofed mammal, and the pygmy hippopotamus is the closest living relative of dolphins and whales. In all cetacean species, paternal care is absent, and the maternal bond is more important.

The book extensively analyzes the umwelten of various cetacean species. Covering all of that would take a long time, so I will focus on a few species of Delphinidae within odontocetes, including killer whales, deep-diving pilot whales, and bottlenose dolphins.

Cetaceans, especially odontocetes, have significant cortical folding (gyrification), resulting in a neocortical surface larger than any other mammal (28). They predominantly rely on hearing and echolocation (30). Dolphins produce echolocation clicks within their blowhole apparatus, send them through their rounded heads, and interpret the returning echoes (52). They also communicate with clicks and whistles that travel great distances in the ocean (68). We do not yet understand how dolphins decode an object's echoes to represent that object, but their capabilities are astounding.

Bottlenose dolphins are immensely intelligent and have incredible communicative skills. For example, they can interpret novel commands, transfer knowledge among themselves, understand new sequences, and more (46-48). Bottlenose dolphins have "signature whistles," which serve as their names and are learned in the first years of their lives (76). They can recognize the signature whistles of past associates over periods of more than 20 years and can copy one another's signature whistles (83). Additionally, killer whales, Risso's dolphins, and bottlenose dolphins can learn call parameters from other species if housed together. In summary:

Bottlenose dolphins are able to to imitate the behavior, the vocalizations of others, they can form concepts, understand syntax, have long-term social memory, cooperate when hunting, and understand as well as use referential communication (that is, signals that refer to objects or individuals). (88)

Bottlenose dolphins can form close friendships (94-96).

Interestingly, killer whales form stable matrilineal pods where sons and daughters remain in the natal area or with the mother for life, whereas bottlenose dolphins have a fission-fusion society with temporary associations. Unlike mysticetes that sever associations at the end of lactation, odontocete calves might continue to associate with their mothers after weaning, some for life (106). I found the "baby position" that odontocete calves engage in, where they swim under a mother's tail and abdomen (the position from which nursing occurs), very cute (106). Female cetaceans delay reproduction because youngsters have a long juvenile period to develop social, cultural, and ecological skills that favor later survival and reproductive success.

I found this particularly interesting:

Cetaceans that swim together often breathe together, called synchronous breathing. Synchronous breathing can be so well timed that individuals are actually exchanging respiratory droplets, akin to kiss or coughing on one another depending on how you think about it. Synchronous breathing rates are high for closely bonded individuals, such as a mother and calf or members of a male alliance in bottlenose dolphins. (P. 112)

If a bottlenose rests his pectoral fin on the flank of another but slightly behind (not parallel), it can indicate bonding. Furthermore, bottlenose dolphins live in "fission-fusion" societies, meaning their membership changes throughout the day. However, bottlenose dolphins form long-lasting adult male alliances, where males cooperate against other alliances to gain access to cycling females (114).

In bottlenose dolphins, there are no pair-bonds to defend and community boundaries are not well defined. Thus, male alliances benefit by outcompeting other alliances, sharing in mating and possibly distributing mating success (fertilizations) among members of the alliance in sequential consortship events... bottlenose dolphin alliances tend to stay together or at least near each other, all the time... First males swim tightly together and in synchrony. They often pet, rub, and mount each other. They usually separate a bit to forage, but come back together to rest, travel, or socialize. Second, the alliance cooperates in securing a single female during the breeding season. Sometimes the males rush upon the female and sometimes they attack her, especially if she tries to escape. (P. 117)

Cetaceans can form cliques, for example, associating more with others that share the same tactics for foraging specializations. One feature of most cetacean societies is that they are sex-segregated, with females preferentially associating with other females and males with other males.

Cetaceans also have a culture, which is behavior or information that is socially learned and shared within a social community. There are local and regional variations in cultures, such as in killer whales.

Now we are beginning to fully appreciate the scope of cultural processes in the cetacean behavior. A humpback whale learns the song he sings from other humpbacks, and in turn is a model for other singers. Over thousands of miles of ocean, the song culture of the humpback whale dominates the acoustic environment, as it has for millions of years. Young killer whales learn the specific and highly honed techniques that their group uses to obtain food and this learned behavior feeds back to affect their biological evolution over many generations, so, for example, the genes involved in digestion evolve along different lines in mammal-eaters compared to fish-eaters. Bottlenose dolphins open up new niches by inventing novel methods for catching fish, and form social networks built around these feeding lifestyles. (P. 125).

In a cultural species, a single innovation can change the behavior of a whole population. Moreover, many hunting techniques are according to family tradition and require learning. Bottlenose dolphins, killer whales, and sperm whales have very rich cultures. The bottlenose dolphin's skill of "sponging" on the seafloor to uncover fish is passed down from mothers, typically to females in Indo-Pacific bottlenose dolphins (153).

Tool-use: Humpback whales can perform bubble-net feeding (151). Bottlenose dolphins can make mud rings for feeding (152). The bottlenose dolphin's skill of "sponging," which involves taking a sponge and rubbing it across the seafloor to uncover fish, is passed down from mothers, typically to females in Indo-Pacific bottlenose dolphins (153). These behaviors are innovated and socially learned, passed down for generations (156-158).

Sadly, dolphins are suffering and dying massively from industrial whaling (especially in the early 20th century), massive oil spills (e.g., 2014 DWH spill) causing reproductive and endocrine failures, POPs chemicals accumulating in tissues, death from gill nets, sound pollution from human maritime operations that interfere with the communication necessary for finding others, sonar and seismic exploration causing beaching, and much more. There was nothing on microplastics or nuclear radiation either.

Finally, here are my thoughts:

Cetaceans are clearly self-aware and intelligent creatures. They have suffered greatly due to industrialization, which has introduced numerous novel problems. In pre-industrial times, when human populations were sparse, the impact of subsistence hunting was minimal. Aboriginal peoples maintained sustainable population levels without advanced technology, but with industrial methods and population growth, the situation has worsened significantly.

Regulations often prove inefficient as industries seek to minimize costs and exploit loopholes. Conservation efforts generally fall short because they operate within the industrial system rather than challenging its foundational issues. The system itself generates the very problems it claims to address, making substantial change difficult to achieve.

I found the book's constant focus on "learning more" and "gathering more controlled data" somewhat repetitive. While I find John C. Lilly's methods and ethics questionable, I believe there is a balance to be struck between the perspectives of New Agers like Lilly and the mechanized scientists focused on replicability and controls. Simply observing cetaceans with non-judgmental awareness, frequently and for extended periods, clearly demonstrates their high level of self-awareness and intelligence. Some experiments in the book, such as using a large machine with a keyboard to see if dolphins can press the correct buttons (49), seem wasteful and misguided.

Additionally, I find it noteworthy that the book does not mention that dolphins were once used in warfare, with bombs strapped to them to target enemy vessels.

[The Inquisitive Biologist · Rating 5 out of 5]

Deep Thinkers joins a line-up of recent books on intelligence in cetaceans, offering the most accessible and well-illustrated book on the topic so far. See my full review at https://inquisitivebiologist.com/2017...

[Melissa · Rating 5 out of 5]

Excellent summary of cetaceans!

Explores the biology, history and future threats to our cetaceans. Great read for the marine biologist or non scientist. Highly recommend to anyone looking to learn more about cetaceans.

[jedioffsidetrap]

Sandmyers