How Many Neurons in the Dolphin Brain?
This article aims to answer the question of how many neurons does the dolphin brain have. It will also highlight how intelligent dolphins are, what capabilities they possess, and some other facts about dolphins. The article will also cover several frequently asked questions regarding the topic.
How Many Neurons in the Dolphin Brain?
Dolphins have approximately 37.2 × 109 neurons, which is almost two times as many as humans, and 127 × 109 glial cells.
Dolphins belong to the Cetaceans species. There are two types of cetaceans namely odontocetes, who are toothed whales and mysticetes, which are baleen whales (Gingerich et al.1983).
Cetaceans went through major transformations in their bodily forms during secondary adaptation to water. This resulted in them having highly encephalized as well as huger brains as compared to other terrestrial mammals (Oelschläger and Oelschläger, 2002).
Previously it was believed that organisms that have large brains are more intelligent. Thus, it is no surprise that dolphins, who possess larger brains as well as display complex behaviour are believed to be very intelligent.
Research has found that there are 12.8 billion neurons in the neocortical neurons in the Minke whale. This means that the minke whale has 13 times more neurons as compared to rhesus monkeys and 500 times more than rats! However, the minke whale only possessed about 2/3rd of its neurons compared to the human neocortex.
These findings are interesting because it highlights that Minke whales, who are a species of dolphin, are shown to have more neocortical neurons as compared to any other mammal studied to date.
However, since the neuron density in long-finned pilot whales is found to be lower than the neuron density in humans, the large number of neurons in dolphins can be attributed to their bigger brains.
When we discuss cetacean intelligence, it includes the discussion of cognitive abilities of the cetacea of mammals. Cetacean mammals include whales, porpoises, and dolphins.
Brain size has been considered to be a predictor of intelligence in animals. However, newer studies have shown that there are several factors influencing intelligence as new evidence of birds’ intelligence has come up. Thus, we now know that a bigger brain does not necessarily equal more intelligence.
The brain is used for the maintenance of bodily functions, and thus, the greater the ratio of brain to body mass, the more mass is available for the brain to perform complex cognitive tasks.
It has been found that dolphins have a faster brainstem transmission time as compared to humans. The speed of brainstem transmission in dolphins is equivalent to that of rats.
Dolphins have a greater dependence on sound processing, and this is evident in the structure of their brain. Interestingly, the neural areas that are responsible for visual imaging are equivalent to 1/10th of the human brain. However, the neural area devoted to acoustical imaging is around 10 times as large as compared to the human brain.
Some research has also highlighted that dolphins are one of the fewer animals that understand concepts of numerical continuity, and are able to distinguish between different numbers.
Numerous research focused on observing the abilities of animals to learn set formation have found that dolphins have nearly the same level of intelligence as elephants. In a survey done in 1983, it was found that dolphins rank highly in the learning of “set formation”, but they’re not as good as other animals.
Dolphins engage in play behaviour that is complex including the production of stable underwater toroidal air-core vortex rings. This is also called “bubble rings”. Dolphins are also found to play by riding in the waves, much like human “body-surfing”.
Dolphins also have self-awareness. Self-awareness is described as an advanced process similar to meta-cognition (thinking about thinking) which is typical in humans. Scientific research has suggested that bottlenose dolphins apart from elephants and great apes possess the skill of self-awareness.
The self-awareness test used for assessing it in animals is the mirror test developed by Gordon Gallup (1970) and is the most widely used test. Here, a temporary dye is placed on the animal’s body and the animal is placed in front of a mirror. The test assesses whether the animal is able to identify itself.
Marten and Psarakos tested the self-awareness of dolphins in 1995. They showed real footage of the dolphins through television of dolphins identifying themselves in the mirror. They concluded that their study suggests the ability of self-awareness in dolphins rather than social behaviour.
These kinds of studies have not been replicated after this study, however it has been concluded that there is evidence for claiming that dolphins have passed the mirror test.
Nevertheless, there are researchers that have argued that there is lacking evidence to suggest dolphins have self awareness, and the existing evidence is not convincing enough.
It is believed that dolphins are the second smartest animal after humans. They’re smarter than even primates. Since dolphins have a high brain-to-body weight ratio, it is understood that dolphins are capable of solving complex problems and understanding abstract concepts.
They are quick at learning and are self-aware. They are known to use basic tools for their protection.
Dolphins also have both emotional and social intelligence. They are known to experience the emotions of grief, pain, and joy. These emotions are usually only present in animals who have a complex brain.
Dolphins also have their own personalities. Some dolphins are more outgoing, extroverted and playful while others are introverted and shy. Dolphins also value social connection as they spend most of their time in groups. They teach their fellow dolphins as well as learn from them. Thus, it is believed that in larger groups, dolphins have a higher level of intelligence.
Sounds and Dolphins
Dolphins are known to emit two distinct sounds, which are called whistles and clocks. Whistles are used by dolphins for communicative reasons.
It has been suggested by research that specific whistles by dolphins are used in order to identify and call each other. Dolphins basically have the tendency to emit other specimens’ signature whistles as well as their own. This ability of dolphins is truly commendable.
Facts about Dolphins
Here are some interesting facts about dolphins:
Dolphins’ pregnancies last anywhere between nine to 16 months. Dolphins feed their babies milk. The sons and daughters of the dolphin mother stay with their maternal family forever. They’re closely knit to their maternal side of the family.
Dolphins are known to eat fish, squid, and crustaceans. Dolphins break their food into smaller pieces and then swallow it, instead of chewing food.
The killer whale, or orca, is the largest dolphin whereas Hector’s dolphin and Franciscana are the smallest.
The lifespan of dolphins varies from 20 years in the smaller dolphin species to 80 years or more for larger dolphins such as orcas.
This article answered the question of how many neurons the dolphin brain have. It also highlighted how intelligent dolphins are, what capabilities they possess, and some other facts about dolphins. The article also covers several frequently asked questions regarding the topic.
Frequently Asked Questions: How Many Neurons in the Dolphin Brain?
Are Dolphins Smarter Than Humans?
No, dolphins are not smarter than humans. Even though dolphins use simple tools and process unique abilities that are present only in complex animals, they don’t use tools at the same level. They don’t use higher-order thinking or decision-making as compared to humans.
Are dolphins smarter than most whales?
Dolphins and whales have roughly the same level of intelligence.
How much is an elephant’s EQ?
In Asian elephants, the EQ is found to be at an average of 2.14 whereas it is 1.67. The overall average EQ of elephants is 1.88.
Which animal has 32 brains?
Leech has 32 brains. The leech’s internal structure is divided in 32 separate segments and each segment has a brain of its own. Leech is known to be an annelid.
Does a big head mean a big brain?
The size of the head depends upon several factors such as the muscularity of the head, and the thickness of the bones surrounding it. However, there is the likelihood that a bigger head may be equivalent to a bigger brain. However, according to Hurlburt (1996), is not necessary that people with bigger brains are smarter than those people who have smaller brains.
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Fields, R. Douglas (2008-01-15). “Are Whales Smarter than We Are?”. Mind Matters. Scientific American Community. Archived from the original on July 27, 2010. Retrieved 2010-10-13.
Marino, Lori (2004). “Cetacean Brain Evolution: Multiplication Generates Complexity” (PDF). International Society for Comparative Psychology (17): 1–16. Archived from the original (PDF) on 2012-11-20. Retrieved 2010-08-29.
Marten, Ken and Psarakos, Suchi “Using Self-View Television to Distinguish between Self-Examination and Social Behavior in the Bottlenose Dolphin (Tursiops truncatus)” (Consciousness and Cognition, Volume 4, Number 2, June 1995)
Mortensen HS, et al. (2014). “Quantitative relationships in delphinid neocortex”. Front Neuroanat. 8: 132. doi:10.3389/fnana.2014.00132. PMC 4244864. PMID 25505387