top of page

Blog

Dolphins- Our Marine based counterparts

Updated: Apr 24, 2018

By Robert Madigan

Ever since my childhood, I have been fascinated with the distinction of what makes humans different to other organisms. It is universally agreed that it is our intelligence, our capacity for logic, reasoning and self-awareness, that sets us apart from the animal kingdom, almost into a kingdom of our own. For humans alone have created a society of such sophistication; constantly seeking to advance our technologies, enrich our cultures, and further our understanding of the laws of nature. Yet, as with many things in life, our definition of intelligence, of what this single determining factor actually comprises, is fundamentally uncertain. In essence, nature is a problem-solver. When faced with a challenge, nature (more often than not), will find a way. It is this adaptability and ability to overcome, even thrive, on change that poses a considerable challenge to the authenticity of our definition of intelligence (and sole-ownership thereof).

Just off our very shore here in County Clare, one particularly interesting example of heightened intelligence in animals can be found: the bottlenose dolphin (Tursiops truncatus). Belonging to the family Delphinidae of oceanic dolphin, this species inhabits temperate seas worldwide. Characteristics of this species include a short, thick beak, robust body, and a light gray/black coloration which lightens around the belly. Each adult weighs an average of 300 kg, can reach a length of between 6- 12.5 ft, and are capable of living up to and beyond 40 years of age (with some females reported to exceed 60 years of age) (1),(2). Individuals typically belong to groups of between 2 and 15 members. 



The Shannon estuary is home to the only known resident group of Bottlenose dolphins in Irish waters, and one of only six such groups in Europe (3). Calves of this group are typically born between May and August. Dolphin watching is a unique and popular tourist attraction for visitors to Clare (and locals), with tours running most of the year to observe them. I myself plan to partake in a tour this year during the calving season in the hope of catching a glimpse of a pod of dolphins, alongside their newborn calves. If I'm lucky enough (with the weather too), I may even get to take a few close up pictures of the dolphins swimming near the vessel!


The intelligence of this species has been widely appreciated and documented and, likes us, represents their most important characteristic. In physiological terms, the brain of a bottlenose dolphin is large in comparison to their bodies, with MRI (Magnetic Resonance Imagine) scans showing them to be 4-5 times larger than the brains of similar sized animals. In fact, such is the large size of their brains that they are placed second in a list of species demonstrating a higher encephalization ratio, which essentially compares the mass of the brain against its body size (4). Dolphin brains are similar to human brains in that they have two hemispheres, but unlike us, their brains are divided into four lobes instead of three. This fourth lobe hosts all of the individuals senses, unlike in human brains where all of the senses are controlled in different parts. It has even been suggested that having all of the senses in one location allows dolphins to make quick and complex judgments that are even beyond the scope of human capability (4).


Our observations on these creatures have found them to be capable of a number of feats considered to be quite 'human'. They are naturally curious and playful creatures, often taking interest in inanimate objects in their surroundings or swimming alongside vessels. Their ability to learn has been described as comparable to that of a 3-year-old child, hence their popularity as attractions in water parks. In addition to this, they are highly sociable animals which demonstrate a capacity for complex communication and even collaborate with other species. They have also been shown to be capable of experiencing emotions such as sadness or joy and can solve complex problems as demonstrated by one such dolphin, Tanner, who could imitate the actions of its trainer whilst blindfolded by using emitting sounds and interpreting the sound waves (4).



As our understanding of different levels of intelligence in animals continues to evolve, the meaning of the term 'intelligence' is becoming exceedingly more difficult to define. Is intelligence merely a capacity to solve increasingly complex problems? Is it more physiological in nature, relating to the size of the brain in comparison to the body? Is the answer more to do with a capacity to experience emotion? Or perhaps a combination of these things? As society continues to assess the issues of keeping animals in captivity, especially those of a high level of awareness, we may need to re-evaluate our interactions with these animals. Already in India, dolphins have been given the status of 'non-human persons' on account of their intelligence, forbidding the captivity of dolphins for entertainment purposes. Being intelligent beings ourselves, we uphold values of respect for one another. Perhaps it is time we extend this respect beyond our own species?


References:

(1) Reeves, R.; Stewart, B.; Clapham, P.; Powell, J. (2002). National Audubon Society Guide to Marine Mammals of the World. New York: A. A. Knopf. pp. 362–365

(2) NOAA Fisheries (2015). Bootlenose Dolphin (Tursiops truncatus): http://www.nmfs.noaa.gov/pr/species/mammals/dolphins/bottlenose-dolphin.html

(3) Dolphin Discovery, Kilrush: Bottlenose Dolphins in the Shannon- A Unique Visitor Attraction in Ireland: http://discoverdolphins.ie/shannondolphins.html

(4) Dolphins-World, (2017). Dolphin Intelligence: https://www.dolphins-world.com/dolphin-intelligence/

88 views1 comment

Recent Posts

See All
bottom of page