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Why the dolphin? The evidence review (October 28, 2026 edition)

By The editors of the Democratic Republican PartyPublished How we check facts

The short answer

We chose the dolphin to stand for cooperation, not because dolphins are virtuous. Bottlenose dolphins coordinate in some studied tasks, and the same species also coerces, fights and sometimes kills. The symbol states our intention; the evidence on this page and the next shows the whole animal.

We chose the dolphin to represent cooperation. That choice does not make dolphins virtuous. Their behavior includes cooperation, competition, and aggression. A symbol expresses an intention; it does not supply the evidence for it.

So this page does two things at once. It shows what researchers have actually measured about dolphin cooperation, with the species, the setting and the number of animals named. Then, without a break, it shows the record a mascot usually leaves out. If the symbol cannot survive the evidence, the evidence wins.

Setting and species

"Dolphin" covers dozens of species, and the studies below do not describe all of them. Almost everything on this page concerns two closely related animals that are both called bottlenose dolphins:

The settings matter as much as the species. Two of the cooperation findings come from dolphins in human care, working on tasks that people designed. The alliance findings come from free-ranging dolphins in one bay. The injury and mortality findings come from animals found dead on particular coastlines and examined by pathologists. Each kind of evidence answers a different question, and none of them speaks for every dolphin everywhere.

The cooperation evidence

A button task in Florida. Kelly Jaakkola and colleagues worked with four common bottlenose dolphins, forming two pairs, at the Dolphin Research Center in Grassy Key, Florida, where the animals live in natural seawater lagoons pmc.ncbi.nlm.nih.gov. Each dolphin had to swim across the lagoon and press its own underwater button within one second of its partner. The researchers then released the partners at different times, with delays of up to 20 seconds, so that one dolphin had to arrive and wait. Over the course of the study, March 2017 to February 2018, the gap between the two presses shrank to an average of about 370 milliseconds in the final phase, and success rates in the randomized delay phase ran from 18 to 20 trials out of 20 for each dolphin pmc.ncbi.nlm.nih.gov. The authors concluded that "bottlenose dolphins can learn to understand their partner's role in a cooperative situation" pmc.ncbi.nlm.nih.gov.

A rope task in Japan. Chisato Yamamoto and colleagues adapted a rope pulling test, long used with primates, for three bottlenose dolphins at the Kagoshima City Aquarium: one juvenile male and two adult females, forming two pairs pmc.ncbi.nlm.nih.gov. Both ends of a rope had to be pulled at the same time to obtain a reward. When one dolphin was released first, by 3, 5 or 8 seconds, one pair still succeeded above chance at every delay; the other succeeded at 3 seconds but not at 8 pmc.ncbi.nlm.nih.gov. The first dolphin to arrive often waited longer when the delay was longer. The authors were careful about what this means: "it remains to be elucidated whether coordination in our dolphins represented intentional cooperation" pmc.ncbi.nlm.nih.gov.

In the wild, cooperation is real and it is not always gentle. In Shark Bay, Western Australia, Richard Connor and colleagues analyzed association and consortship records collected from 2001 to 2006 on 121 adult male Indo-Pacific bottlenose dolphins doi.org. The males form alliances at three levels: pairs and trios, larger groups of 4 to 14 that compete with other groups, and alliances between those groups. The authors describe it as "the largest nonhuman alliance network known" doi.org. NOAA Fisheries also describes common bottlenose dolphins working together to herd schools of fish and taking turns feeding fisheries.noaa.gov.

That is the strongest honest case for the symbol: in specific studies, dolphins coordinate their actions with partners, and in one wild population, males maintain cooperative relationships at a scale seen in few other animals.

It is also exactly where the uncomfortable record begins, because the purpose of those Shark Bay alliances is competition over females.

The uncomfortable record

Read the cooperation evidence above and then read this. They describe the same animals.

Cooperation that coerces. In Shark Bay, the pairs and trios at the base of the alliance network form what the researchers call "aggressively maintained consortships" with individual females, lasting hours to weeks doi.org. A 2019 study by Stephanie King and colleagues defines herding as an association in which two to three males "use vocal and physical threats to coerce a female to accompany them," and classifies it as coercive mate guarding, a form of sexual coercion that "functions to constrain female mate choice" pmc.ncbi.nlm.nih.gov. Males who were better connected to allies outside their own group kept females in consortship for longer doi.org. Cooperation among the males is what makes the coercion work. Cooperation alone does not guarantee a good outcome for everyone involved.

Calves killed by adults. On the northeast coast of Scotland, post mortem examinations found that five of eight young bottlenose dolphin calves from one area had been killed by bottlenose dolphins, and researchers directly observed an adult in an aggressive interaction with a dead calf pmc.ncbi.nlm.nih.gov. In Virginia, nine bottlenose calves that stranded in 1996 and 1997 had died of severe blunt force trauma; the pathologists ruled out boat strike, fisheries, predation, surf and blast injury and concluded that the evidence suggests infanticide occurs in that population digitalcommons.odu.edu. These are findings for specific populations, mostly reached by examining bodies rather than by watching the events.

Lethal attacks on porpoises. The same Scottish study reports that most harbor porpoises found dead on that coast show signs of attack by bottlenose dolphins pmc.ncbi.nlm.nih.gov. In the German Baltic Sea in 2016, a single male bottlenose dolphin stayed for three months, and six stranded porpoises from that period showed rib fractures and internal bleeding consistent with dolphin attacks elsewhere; no attack was witnessed link.springer.com. Why bottlenose dolphins attack porpoises is still debated.

Risks to people. NOAA Fisheries states that wild dolphins bite, that "dozens of bites have been reported, and people have been pulled underwater," and that the friendly wild dolphin of television is a myth fisheries.noaa.gov. In Sarasota Bay, Florida, dolphins that had learned to take food from people were more likely to be injured by human interactions than dolphins that had not pmc.ncbi.nlm.nih.gov. Feeding dolphins harms them and puts people at risk.

Read the whole record: the complete evidence review, with species, populations, sample sizes and open questions

The whole record also covers predation, popular myths about dolphins, and the limits of what captive studies can tell us about wild animals. It separates what was observed from what was inferred from a body, what was tested in an experiment, and what is only a proposed explanation.

Why a modern mark on an old name

The Democratic-Republican Party is a historical subject. This site studies it: its formation, its governing years, who held power and who was excluded, and how its coalitions came apart. The dolphin is not part of that history. It is a contemporary mark made for this project, and nothing on this site should be read as saying the historical party used it, chose it, or would have recognized it.

Putting a new symbol on an old name is a choice with a risk built in. A dolphin can sentimentalize a serious history, or it can make people curious enough to read it. We made the choice for one reason: cooperation across disagreement is a value worth stating plainly, and "Left. Right. Forward." is modern editorial language for that value.

A symbol that asks to be trusted has to be examined in public. That is why the evidence against the mascot sits directly under the evidence for it, and why the same standard is applied to the elephant and the donkey in What a mascot leaves out.

Do not feed, touch, swim with, or harass wild dolphins

A dolphin on a website is not an invitation to approach a dolphin in the sea. In the United States, wild dolphins are protected under the Marine Mammal Protection Act.

  • Do not feed or attempt to feed them. NOAA Fisheries states that feeding or attempting to feed wild dolphins is prohibited under the Marine Mammal Protection Act and its regulations, and that violations can be prosecuted civilly or criminally fisheries.noaa.govfisheries.noaa.gov.
  • Do not swim with, ride, pet or touch them. NOAA's viewing guidelines say: "Do not swim with, ride, pet, touch, or attempt to interact with marine mammals or sea turtles in the wild" fisheries.noaa.gov.
  • Keep your distance. NOAA advises staying at least 50 yards away, and notes that some locations require 100 yards fisheries.noaa.govfisheries.noaa.gov. Never put a boat between a mother and calf fisheries.noaa.gov.
  • Do not harass them. NOAA describes harassment under the act at two levels: acts that have the potential to injure a marine mammal, and acts that have the potential to disturb its behavior, such as feeding or nursing fisheries.noaa.gov.

The reasons are documented. Dolphins that are fed lose their caution around people and boats, which raises their risk of propeller strikes and entanglement in fishing gear fisheries.noaa.govfisheries.noaa.gov. NOAA reports that young dolphins can fail to survive when their mothers stop teaching them to forage and compete with them for handouts fisheries.noaa.gov. In Sarasota Bay, a study drawing on more than 45 years of records and more than 1,100 individual dolphins found that dolphins conditioned to human interaction were more likely to be injured by it pmc.ncbi.nlm.nih.gov. And dolphins that expect food can bite fisheries.noaa.govfisheries.noaa.gov.

Evidence

How strong is each finding on this page? The answer depends on the kind of evidence.

Finding Species and setting Kind of evidence Sample
Partners coordinate button presses Common bottlenose, captive, Florida Experiment 4 dolphins, 2 pairs pmc.ncbi.nlm.nih.gov
Partners coordinate rope pulling Common bottlenose, captive, Japan Experiment 3 dolphins, 2 pairs pmc.ncbi.nlm.nih.gov
Three level male alliances Indo-Pacific bottlenose, wild, Shark Bay Long term observation 121 adult males doi.org
Herding of females by allied males Indo-Pacific bottlenose, wild, Shark Bay Direct observation Focal follows, 2016 to 2017 pmc.ncbi.nlm.nih.gov
Calves killed by dolphins Common bottlenose, wild, Scotland and Virginia Forensic inference, one direct observation 5 of 8 calves; 9 calves pmc.ncbi.nlm.nih.govdigitalcommons.odu.edu
Porpoises killed by dolphins Common bottlenose, wild, Scotland and German Baltic Forensic inference Six porpoises in the Baltic case pmc.ncbi.nlm.nih.govlink.springer.com
Fed dolphins injured more often Common bottlenose, wild, Sarasota Bay Long term observation More than 1,100 dolphins pmc.ncbi.nlm.nih.gov

What the evidence does not show

  • It does not show that all dolphins cooperate, or that dolphins cooperate in general. The two experiments tested seven animals in total, all in human care, on tasks humans designed pmc.ncbi.nlm.nih.govpmc.ncbi.nlm.nih.gov.
  • It does not show that the experimental dolphins understood cooperation the way a person would. One team concluded they could learn a partner's role; the other said intentional cooperation remains unproven pmc.ncbi.nlm.nih.govpmc.ncbi.nlm.nih.gov.
  • It does not show that all dolphins coerce, commit infanticide, or attack porpoises. Those findings come from particular populations and, for infanticide and porpoise deaths, mostly from examining bodies rather than watching the events doi.orgpmc.ncbi.nlm.nih.govpmc.ncbi.nlm.nih.govdigitalcommons.odu.edulink.springer.com.
  • It does not show why these behaviors happen. Proposed explanations exist, and the whole record keeps them separate from what was observed.
  • It does not tell us anything about human politics. Dolphin behavior is not a model for a party, a voter or a government, and nature does not endorse anyone's politics, including ours.

Sources

  1. Jaakkola K, Guarino E, Donegan K, King SL, "Bottlenose dolphins can understand their partner's role in a cooperative task," Proceedings of the Royal Society B 285(1887): 20180948, 2018. pmc.ncbi.nlm.nih.gov (locator: Methods a to e; Results; Table 3; Discussion). Accessed 2026-10-28. (full text reviewed)
  2. Yamamoto C, Kashiwagi N, Otsuka M, Sakai M, Tomonaga M, "Cooperation in bottlenose dolphins: bidirectional coordination in a rope-pulling task," PeerJ 7: e7826, 2019. pmc.ncbi.nlm.nih.gov (locator: Methods; Results; Conclusions). Accessed 2026-10-28. (full text reviewed)
  3. Connor RC, Krützen M, Allen SJ, Sherwin WB, King SL, "Strategic intergroup alliances increase access to a contested resource in male bottlenose dolphins," Proceedings of the National Academy of Sciences 119(36): e2121723119, 2022. doi.org (full text read at pmc.ncbi.nlm.nih.gov; locator: Abstract; Introduction; Materials and Methods; Results). Accessed 2026-10-28. (full text reviewed)
  4. King SL, Allen SJ, Krützen M, Connor RC, "Vocal behaviour of allied male dolphins during cooperative mate guarding," Animal Cognition 22: 991 to 1000, 2019. pmc.ncbi.nlm.nih.gov (locator: Abstract; Introduction; Methods, Behavioural data). Accessed 2026-10-28. (full text reviewed)
  5. Patterson IAP, Reid RJ, Wilson B, Grellier K, Ross HM, Thompson PM, "Evidence for infanticide in bottlenose dolphins: an explanation for violent interactions with harbour porpoises?" Proceedings of the Royal Society B 265(1402): 1167 to 1170, 1998. pmc.ncbi.nlm.nih.gov (locator: Abstract). Accessed 2026-10-28. (abstract only)
  6. Dunn DG, Barco SG, Pabst DA, McLellan WA, "Evidence for infanticide in bottlenose dolphins of the western North Atlantic," Journal of Wildlife Diseases 38(3): 505 to 510, 2002. digitalcommons.odu.edu (locator: Abstract). Accessed 2026-10-28. (abstract only)
  7. NOAA Fisheries, "Protect Wild Dolphins: Admire Them from a Distance," last updated October 3, 2023. fisheries.noaa.gov (locator: full page). Accessed 2026-10-28. (full text reviewed)
  8. NOAA Fisheries, "Frequent Questions: Feeding or Harassing Marine Mammals in the Wild," last updated January 20, 2026. fisheries.noaa.gov (locator: full page). Accessed 2026-10-28. (full text reviewed)
  9. Christiansen F, McHugh KA, Bejder L, Siegal EM, Lusseau D, McCabe EB, Lovewell G, Wells RS, "Food provisioning increases the risk of injury in a long-lived marine top predator," Royal Society Open Science 3(12): 160560, 2016. pmc.ncbi.nlm.nih.gov (locator: Abstract; Methods 2.1; Results). Accessed 2026-10-28. (full text reviewed)
  10. Gross S, Claus P, Wohlsein P, Kesselring T, Lakemeyer J, Reckendorf A, Roller M, Tiedemann R, Siebert U, "Indication of lethal interactions between a solitary bottlenose dolphin (Tursiops truncatus) and harbor porpoises (Phocoena phocoena) in the German Baltic Sea," BMC Zoology 5: 12, 2020. link.springer.com (locator: Abstract, Background, Results, Conclusion). Accessed 2026-10-28. (abstract only)
  11. NOAA Fisheries, "Common Bottlenose Dolphin," species page, last updated September 1, 2026. fisheries.noaa.gov (locator: diet, behavior and threats sections). Accessed 2026-10-28. (full text reviewed)
  12. NOAA Fisheries, "Marine Life Viewing Guidelines: Guidelines and Distances." fisheries.noaa.gov (locator: General Viewing Guidelines; dolphins and porpoises; watercraft). Accessed 2026-10-28. (full text reviewed)

Last checked against its sources on October 28, 2026. Report a correction.