An analysis of mirror self recognition in bottlenose dolphins

Mirror self-recognition in the bottlenose dolphin: A case of cognitive convergence. Proceedings of the National Academy of Sciences. Abstract Mirror self-recognition MSR is an exceedingly rare capacity in the animal kingdom.

An analysis of mirror self recognition in bottlenose dolphins

Life history[ edit ] Respiration and sleep[ edit ] The bottlenose dolphin has a single blowhole located on the dorsal surface of the head consisting of a hole and a muscular flap. The flap is closed during muscle relaxation and opens during contraction.

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They can store almost twice as much oxygen in proportion to their body weight as a human can: This is an adaptation to diving. During the sleeping cycle, one brain hemisphere remains active, while the other hemisphere shuts down.

The active hemisphere handles surfacing and breathing behavior. During the sleeping cycle, they remain near the surface, swimming slowly or "logging", and occasionally closing one eye. The male can retract and conceal his penis through his slit.

Females have two mammary slits, each housing one nippleone on each side of the genital slit. The breeding season produces significant physiological changes in males. At that time, the testes enlarge, enabling them to hold more sperm. Large amounts of sperm allow a male to wash away the previous suitor's sperm, while leaving some of his own for fertilization.

Also, sperm concentration markedly increases. Having less sperm for out-of-season social mating means it wastes less. This suggests sperm production is energetically expensive.

Males have large testes in relation to their body size. Such competition can take the form of fighting other males or of herding females to prevent access by other males. Newborn bottlenose dolphins are 0.

The calf suckles for 18 months to up to 8 years, [97] and continues to closely associate with its mother for several years after weaning.

An analysis of mirror self recognition in bottlenose dolphins

She cites studies showing these dolphins as adults are inseparable, and that early bonds aid protection, as well as in locating females. Adult females and young dolphins normally live in groups of up to 15 animals.

In a dolphin community near Sarasota, Florida, the most common group types are adults females with their recent offspring, older subadults of both sexes and adult males either alone or in bonded pairs.

They also eat shrimps, squid, mollusks, and cuttlefish, and only swallows the soft parts. They eat 22 pounds of fish a day. When they encounter a shoal of fishthey work as a team to herd them towards the shore to maximize the harvest.

The bottlenose dolphin sometimes hits a fish with its fluke, sometimes knocking it out of the water, using a strategy called "fish whacking". When a pod finds a school of fish, they will circle the school and trap the fish in a mini whirlpool.

Then, the dolphins will charge at the school and push their bodies up onto a mud-flat, forcing the fish on the mud-flat, as well.

The dolphins then crawl around on their sides, consuming the fish they washed up on shore. Bottlenose dolphins conflict with small-scale coastal commercial fisheries in some Mediterranean areas.

Common bottlenose dolphins are probably attracted to fishing nets because they offer a concentrated food source. On Mahia BeachNew Zealand, on March 10,[] two pygmy sperm whalesa female and calf, stranded on the beach.

Rescuers attempted to refloat them four times. Males fight for rank and access to females. During mating season, males compete vigorously with each other through displays of toughness and size, with a series of acts, such as head-butting.

They display aggression towards sharks and smaller dolphin species. At least one population, off Scotlandhas practiced infanticideand also has attacked and killed harbour porpoises.

University of Aberdeen researchers say the dolphins do not eat their victims, but are simply competing for food. Read of Duke University, a porpoise expert researching similar cases of porpoise killings that had occurred in Virginia in andholds a different view.

He states dolphins and porpoises feed on different types of fish, thus food competition is an unlikely cause of the killings.

Killer whale populations in New Zealand and Peru have been observed preying on bottlenose dolphins, but this seems rare, [] and other orcas may swim with dolphins. Swimming in pods allows dolphins to better defend themselves against predators.According to the report, dolphins, too, exhibit mirror self-recognition.

To test for dolphin self-awareness, Diana Reiss of Columbia University and Lori Marino of Emory University exposed two bottlenose dolphins to reflective surfaces after marking the dolphins with black ink, applying a water-filled marker (sham-marking) or not marking them at all. Analysis of "Mirror Self-Recognition in Bottlenose Dolphins: Implications for Comparative Investigations of Highly Dissimilar Species" Studies using chimpanzees, orangutans, and humans have shown displays of self-recognition with the introduction of a mirror.

Mirror self-recognition (MSR) is an exceedingly rare capacity in the animal kingdom.


To date, only humans and great apes have shown convincing evidence of MSR. In this study we present the first conclusive evidence for self-recognition outside of the primate domain in a species phylogenetically distant and neuroanatomically different from.

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Get started now! The mirror test – sometimes called the mark test, mirror self-recognition test (MSR), red spot technique, or rouge test – is a behavioural technique developed in by psychologist Gordon Gallup Jr. as an attempt to determine whether a non-human animal possesses the ability of visual self-recognition.

Bottlenose dolphins are neuroanatomically different and evolutionarily divergent from primates yet they exhibit mirror self-recognition (MSR), a rare cognitive ability in non-human animals. This research investigated the developmental and age-related aspects of MSR in this species.

Mirror test - Wikipedia