Dolphin Intelligence

What is intelligence?

“Intelligence is the ability to acquire and apply knowledge and skills” (Oxford Dictionaries)

Introduction:

Dolphins are a diverse group of fully aquatic marine mammals.  There are currently 40 species of dolphins spread across the families Delphinidae, Platanistidae, Iniidae, and Pontoporiidae.  Most dolphins primarily consume fish or squid but some dolphins such as killer whales, prey on large mammals (“Basic Facts About Dolphins”, 2016). They possess an extraordinarily acute sense of hearing, with their auditory nerve being approximately twice the diameter of the human vestibulocochlear nerve, allowing them to process auditory information much faster (“Dolphin Senses”, 2016). These factors can play a role in the intelligence of the dolphin.

Basic Anatomy:

The basic anatomy of a dolphin

(Imagine Creative Commons by Wikimedia licensed under CC by 2.0)

• Dolphins have torpedo shaped bodies with generally non-flexible necks, limbs modified into flippers, non-existent external ear flaps, a tail fin, and bulbous heads.
• Dolphin skulls have small eye orbits, long snouts, and eyes placed on the sides of its head.
• Dolphins range in size from the 1.7 meters (5.6 ft) long and 50 kilograms (110 lb) to as big as  9.5 meters (31 ft) and 10 metric tons (11 short tons)!
• Dolphins have conical shape teeth

(Dolphins-World, 2014)

Dolphin Intelligence used in Captivity:

Dolphins are often regarded as one of Earth’s most intelligent animals however just how intelligent are they? It is hard to determine and compare the relative intelligence in  species due to differences in response modes, the nature of cognition as well as their sensory apparatuses (“Dolphin”, 2016). Many types of Dolphins, such as Killer Whales are often used for entertainment for their intelligence. Killer Whales are well known for their performances in shows, but the number of Orcas kept in captivity is very small in relative terms to the number of bottle nose  dolphins (“End Captivity”, 2016). Data based on 2012, has shown us that only about 44 captive killer whales are being held in captivity and this number is declining every year with the ethnical issues that surround it (“Captive Orca Statistic”, 2016). Due to the killer whales intelligence, playfulness, size, and trainability in captivity it has made it become a popular exhibit at aquatic theme parks such as Sea World. Dolphins have a long history of being bred in human captivity.  This practice has recently come under fire, as many people feel that dolphins are too intelligent and socially complex to be kept in captivity (“End Captivity”, 2016). Several scientists who have researched dolphin behavior have proposed that dolphins high intelligence in comparison to other animals should be seen as non-human persons, who should have their own specific rights. This means that it would be morally unacceptable to keep them captive for entertainment purposes or to kill them for consumption or by fishing (BBC, 2012). Four countries including Chile, Hungary, India and Costa Rica have declared dolphins to be “non-human persons” and have banned the capture and import of live dolphins for entertainment. This idea of giving these animals “legal rights” has never been given to any other animal before (Hackman, 2014). Over the next couple years we should see more countries coming into compliance with the idea that dolphins should not be held in captivity based on their intelligence.

The documentary Blackfish reviews many of the arguments against keeping these animals captive, and specifically concerns Sea World’s treatment of their orcas. Since orcas form close familial bonds with one another, taking one from the wild to be kept in captivity is the equivalent of taking a child from its parents (“Born Free Foundation “, 2016). The existence of a paralimbic lobe in cetacean brains was recently discovered.  It sits between the neocortex and limbic system. Many neuroscientists who have studied it believe it to have functionality both in terms of emotional processing and higher thought processing (“Scientific Evidence for Whale and Dolphin Rights”, 2016). Mammals, including humans, lack this lobe entirely leading some to believe that dolphin may exceed humans in their emotional and though processing complexity (Marable & Collins, 2016).

Dolphin Intelligence Related to Humans?

Dolphins are known to teach, learn, cooperate, and even grieve. Their intelligence is thought to come from a similar aspect of humans. The neocortex of many species is a elongated spindle neuron that was only previous known in hominids prior to 2007. (Watson, Jones, & Allman, 2006). In humans, these cells are involved in important life aspects such as  social conduct, emotions, and judgment.  Cetacean spindle neurons are found in the same areas of the brain as where they are found in humans (Hof & Van Der Gucht, 2007). This suggest that they may perform a similar function.

Studies:

Although no one would argue that dolphins certainly rank among Earth’s most intelligent animals, a recent revelation concerning their communicative abilities has raised the bar for their potential intellect even higher.  In a recent paper authored by Vyacheslav Ryabov and published in the St. Petersburg Polytechnical University Journal: Physics and Mathematics, two adult dolphins, Yasha and Yana were recorded communicating through a series of pulses and whistles in a manner reminiscent to human language.  While the fact that dolphins communicate back and forth has been known for a long time, Ryabov showed that the dolphins he recorded modulated both the spacing between their clicks and whistles as well as their duration in a highly complex, nonrepetitive manner.  He states that this finding may be the first evidence for a non-human language and even suggests the creation of a method for translating it (Ryabov, 2016).

Learning and Entertainment:

Dolphins have been used for many years for entertainment in places such as Sea World. Their intelligence has fascinated humans for decades. Below is a video of one of the many tricks dolphins have been trained to do. Their ability to flip through the air on cue is one of their characteristics illustrating their intelligence.

(Imagine Creative Commons by Youtube licensed under CC by 2.0)

 Podcast:

A link to a neat podcast about how humans are trying to communicate with dolphins

http://www.radiolab.org/story/hello/

Links to research labs using Dolphins with respect to intelligence:

• Roatán Institute for Marine Sciences (RIMS)- http://www.roatanims.org/
• University of Hawaii and The Dolphin Institute, U.S.A.-http://www.hawaii.edu/mmrp/MMRP_Hawaii/About.html
• Dolphin Research Center, Florida-https://www.dolphins.org/areas_of_study

*Want to look at other intelligent animals? Below are links to other students websites:

• Cognitive Intelligence in Dogs (https://jaimemarsh.wordpress.com/2016/10/28/cognitive-intelligence-in-dogs/comment-page-1/#comment-3)
•  Cognitive Intelligence in Elephants- ” A Trunk Full of Smarts” (https://melissawydra.wordpress.com/2016/10/28/a-trunk-full-of-smarts/)
  

References:

Basic Facts About Dolphins. (2016). Defenders of Wildlife. Retrieved 9 December 2016, from http://www.defenders.org/dolphin/basic-facts

Dolphin Senses – Dolphin Facts and Information. (2016). Dolphins-world.com. Retrieved 9 December 2016, from http://www.dolphins-world.com/dolphin-senses/

Scientific Evidence for Whale and Dolphin Rights. (2016). WDC, Whale and Dolphin Conservation. Retrieved 9 December 2016, from http://us.whales.org/scientific-evidence-for-whale-and-dolphin-rights

 Watson, K., Jones, T., & Allman, J. (2006). Dendritic architecture of the von Economo neurons. Neuroscience, 141(3), 1107-1112. http://dx.doi.org/10.1016/j.neuroscience.2006.04.084

Hof, P. & Van Der Gucht, E. (2007). Structure of the cerebral cortex of the humpback whale,Megaptera novaeangliae (Cetacea, Mysticeti, Balaenopteridae). The Anatomical Record: Advances In Integrative Anatomy And Evolutionary Biology, 290(1), 1-31. http://dx.doi.org/10.1002/ar.20407

Ryabov, V. (2016). The study of acoustic signals and the supposed spoken language of the dolphins. St. Petersburg Polytechnical University Journal: Physics And Mathematics, 2(3), 231-239. http://dx.doi.org/10.1016/j.spjpm.2016.08.004

https://en.oxforddictionaries.com/definition/intelligence

Dolphin. (2016). ScienceDaily. Retrieved 9 December 2016, from https://www.sciencedaily.com/terms/dolphin.htm

End Captivity. (2016). WDC, Whale and Dolphin Conservation. Retrieved 9 December 2016, from http://us.whales.org/wdc-in-action/end-captivity

Captive Orca Statistic. (2016). Orcahome.de. Retrieved 9 December 2016, from http://www.orcahome.de/orcastat.htm

Born Free Foundation – Keep Wildlife in the Wild. (n.d.). Retrieved December 08, 2016, from http://www.bornfree.org.uk/campaigns/zoo-check/captive-whales-dolphins/global/

Marable, K., & Collins, M. (n.d.). A Comparison of Primate and Cetecean Mentality. Retrieved December 08, 2016, from https://msu.edu/~marablek/whal-int.htm

Dolphins-World. (2014, January 28). Dolphin anatomy. Retrieved December 9, 2016, from http://www.dolphins-world.com/dolphin-anatomy/

Hackman, J. (2014, February 23). India declares dolphins “non-human persons.” Retrieved December 9, 2016, from http://www.trueactivist.com/india-declares-dolphins-non-human-persons-dolphin-shows-banned/

BBC (2012, February 21). Dolphins deserve same rights as humans, say scientists. BBC World. Retrieved from http://www.bbc.com/news/world-17116882