Cocaine Hippos, Monkey Copyrights, and a Horse Named Justice: The Debate Over Animal Personhood

In January, six justices of the Colorado Supreme Court unanimously ruled that five elderly African elephants were not people.

That may not sound like an issue that needs six justices to resolve, but courts around the country have found themselves handling such questions.

The Colorado Supreme Court did not hear from the elephants directly. They heard from the Nonhuman Rights Project, which filed a habeas corpus petition on behalf of the pachyderms, arguing that their confinement in a Colorado Springs zoo violated their right to bodily liberty.

Over the past decade, the Nonhuman Rights Project and several other animal rights groups have waged a novel campaign to extend legal "personhood" to animals, which would allow them to be plaintiffs in civil lawsuits. Many of these cases have attempted to free large, charismatic animals such as elephants and chimpanzees from zoos under the great writ of habeas corpus, which allows individuals to challenge unlawful imprisonment.

Other courts around the world have recognized fundamental rights for animals. In Pakistan, the Islamabad High Court declared in 2020, in the case of a shackled and mistreated elephant, that it "is a right of each animal, a living being, to live in an environment that meets the latter's behavioral, social and physiological needs." In 2022, Ecuador's Constitutional Court ruled that animals were subject to "rights of nature" enshrined in the country's constitution. And last year, indigenous leaders of New Zealand, Tahiti, and the Cook Islands signed a treaty recognizing whales as legal persons.

Critics scoff that this amounts to little more than absurdist lawfare and that legal recognition of animal personhood would almost certainly empower busybody environmentalists—and might not even improve conditions for the animals. There are also public pressure campaigns and existing legal avenues that could improve animal welfare without attempting to shift one of the bedrock principles of Western law.

But the question at the heart of these cases—whether a nonhuman entity can have a cognizable liberty interest—has surprisingly deep implications, not just for animals but for human freedom and flourishing. Research into artificial intelligence (AI) may eventually run into similar ethical considerations.

"There's a lot of tension because I think that the law just hasn't really caught up with our own sensibilities," says Christopher Berry, executive director of the Nonhuman Rights Project. "Primarily courts are trying to police a boundary between humans and animals and not recognizing that things don't always fall into a neat dichotomy."

Pablo's Cocaine Hippos

So far, the only animals that have ever been declared legal persons by a U.S. court in any limited sense are a pod of invasive hippopotamuses in Colombia that escaped from the estate of the cocaine cartel lord Pablo Escobar.

The animals are the descendants of four hippos that Escobar illegally imported in the 1980s. Unsurprisingly, after Escobar's death no one wanted to claim responsibility for a bunch of full-grown hippos, so the animals were left to their own devices. They migrated to nearby rivers and began eating and reproducing.

After several decades, more than 150 gigantic, ill-tempered, territorial animals were tearing up local waterways. The Colombian government finally began developing plans to cull its rogue hippo population, but in 2020 a Colombian lawyer sued on behalf of the hippos, arguing they should be sterilized instead of euthanized.

The Animal Legal Defense Fund (ALDF), a California-based animal rights group, asked the U.S. District Court in Cincinnati to grant "interested persons" status to the hippos in order to depose two Ohio experts on wildlife sterilization to testify on their behalf. The judge granted the request.

This had no practical effect on the hippos' legal status in either the U.S. or Colombia. Colombia's Constitutional Court ruled in 2020 that a bear named Chucho did not possess fundamental rights and therefore could not invoke habeas corpus. But it was the closest thing to a win that animal rights groups could claim on the personhood front in the U.S.

"It's a very small thing to give hippos the ability to depose these two experts, but it just opens the door a little bit that has always been closed," says ALDF attorney Ariel Flint. "My hope is that in the future, judges will be more comfortable holding that door open for other animals because they won't be the first ones to have to do it."

As for the hippopotamuses, the sterilization plan was approved but proceeded slowly, because there aren't many people with the steely nerves and know-how required to tranquilize and neuter a 5-ton bull hippo. Last year, a Colombian court ordered hunting of the animals to resume.

Persons and Things

Francis of Assisi, the Catholic saint said to have preached to birds and tamed a wolf, may have considered all of Animalia his brothers and sisters, but U.S. courts have strenuously rejected that proposition.

In legal philosophy, everything is either a person or a thing. A horse isn't a person, so it's a thing. Even if a horse could talk, even if it could do advanced algebra in front of a judge, it would be a thing, and the most protection a thing can have under the law is as a piece of property.

This was widely accepted back when animals were commonly understood to be commodities. But changing social mores have left many Americans feeling troubled by some of the implications.

Berry cites a 2013 case where the Texas Supreme Court ruled that an owner suing over the negligent death of his pet dog was entitled only to the fair market value of the dog and that pet owners could never recoup damages for emotional or noneconomic losses.

"What the Texas Supreme Court ended up admitting actually was that if you had a taxidermied dog that was a family heirloom, you could receive sentimental damages for that, but you could not receive anything beyond the market value for a family dog who was alive and was killed," Berry says.

A beloved family pet is also property under the Fourth Amendment, protecting them from unreasonable government "seizures" (read: killings). This allows owners to sue when a police officer shoots their dog, but it turns an ugly experience into a bloodless abstraction.

In 2018, lawyers for the city of Detroit tried to argue that unlicensed dogs were "contraband" under the Fourth Amendment, meaning an owner couldn't sue the police for shooting their pet, since owners don't retain a possessory interest in illegal property.

The practical effect of the claim would be that a cop could summarily execute any unregistered dog he or she came across and the owners would have no recourse. Thankfully, the U.S. Court of Appeals for the 6th Circuit rejected that argument, writing that "just as the police cannot destroy every unlicensed car or gun on the spot, they cannot kill every unlicensed dog on the spot."

The person-thing rule isn't always strictly true, either. Animal rights activists are quick to point out that courts are willing to suspend disbelief in instances not involving animals.

As Mitt Romney said, "Corporations are people, my friend." A corporation is both a legal person and property.

The doctrine of civil asset forfeiture allows law enforcement to quickly seize and forfeit property under the legal fiction that it is an action against property, not the owner. The court pretends that the defendant is the property itself. In other words, courts are willing to pretend that the government can sue 23 pit bulls—see: U.S. v. Approximately Twenty-Three Pit Bull-Type Dogs—but not that 23 pit bulls can sue the government.

For animal rights groups, the growing gulf between how society perceives animals and how courts treat them was a problem, but it was also an opportunity to try to push the frontiers of the law.

Habeas Porpoise?

The Colorado case was one of many attempts by the Nonhuman Rights Project to find a court willing to entertain a habeas petition on behalf of a captive animal. The group's late founder, Steven Wise, first advanced the argument for extending legal personhood to animals in his 2000 book Rattling the Cage, and the group filed its first unsuccessful petition on behalf of two captive chimpanzees in 2013.

Other groups got in on the action. In 2003, a lawyer filed a lawsuit on behalf of all whales and dolphins in the world (collectively styled "the cetacean community") challenging the Navy's use of low-frequency sonar.

People for the Ethical Treatment of Animals (PETA) filed an unsuccessful suit on behalf of a SeaWorld orca in 2013, arguing that its captivity violated the 13th Amendment's ban on slavery.

And in 2015, PETA launched perhaps the least serious and least regarded of these cases—the so-called monkey selfie suit. PETA filed a "next friend" lawsuit on behalf of Naruto, an Indonesian macaque, claiming that a wildlife photographer had infringed on Naruto's copyright by publishing a selfie that the monkey took with the photographer's camera.

PETA lost at the district court level and appealed, but while the appeal was pending it reached a settlement with the photographer, who agreed to donate part of the proceeds from the selfie to animal welfare causes. The U.S. Court of Appeals for the 9th Circuit rejected PETA's attempt to dismiss its appeal and ruled that animals cannot file for copyright infringement. The opinion disdainfully noted that PETA appeared to be advancing its own interests rather than those of its "friend" Naruto.

The case created a bad precedent for the cause: The 9th Circuit ruled that animals can't have standing under any federal law unless animals are specifically mentioned. (Part of the reason the ALDF was thrilled about the hippopotamus case was that, contrary to the 9th Circuit, the judge gave the hippos standing under a federal law that did not mention animals.)

In 2018, the Nonhuman Rights Project filed another habeas petition. This one was on behalf of Happy, an Asian elephant confined in a two-acre Bronx Zoo enclosure, seeking to move Happy to a large elephant sanctuary. It was the most high-profile case to date, and the project brought all of its accumulated arguments and expert witnesses to bear, arguing that Happy was a complex, autonomous being whose confinement cruelly deprived her of her essential elephant-ness. Happy was in fact the first elephant to pass the "mirror test," an experiment in which she looked at herself in a mirror and touched her trunk to an x painted on her forehead. Only a few species are capable of self-recognition.

In 2022, the New York Court of Appeals, the state's highest court, issued a 5–2 opinion that Happy had no standing to file a habeas petition. "The selective capacity for autonomy, intelligence, and emotion of a particular nonhuman animal species is not a determinative factor in whether the writ is available as such factors are not what makes a person detained qualified to seek the writ," the majority opinion said. "Rather, the great writ protects the right to liberty of humans because they are humans with certain fundamental liberty rights recognized by law."

But the decision was not unanimous. Two justices dissented, saying that Happy had made a proper showing. Judge Jenny Rivera wrote that Happy was "a sentient being, who feels and understands, who has the capacity, if not the opportunity, for self-determination."

"We cannot elide the question of Happy's legal rights and the use of the writ by a nonhuman animal with empty references to her dignity and 'intelligen[ce],'" Rivera continued. "A gilded cage is still a cage. Happy may be a dignified creature, but there is nothing dignified about her captivity."

Where Human Courts Fail Animals

Philosophical arguments about rights aside, these activists argue that expanding the avenues for animals in civil court would address real-world gaps in enforcement of animal welfare laws.

Our laws recognize that animals have someintrinsic value. Endangered species laws put an ecological value on a species as a whole, while animal cruelty laws protect individual animals from wanton abuse. But the 50 states have a patchwork of animal cruelty laws that vary in which animals are protected and what criminal penalties violators receive, and the laws are unevenly enforced.

Those laws also require government resources to investigate cases. Police and prosecutors may not have the time or motivation to investigate animal abuse, given a choice between that and their human caseload, or they may lack the political will in rural areas heavily reliant on large factory farms, which often obtain carve-outs from cruelty laws. (For example, the federal Preventing Animal Cruelty and Torture Act of 2019, which outlaws crushing, burning, drowning, suffocating, impaling, or sexual exploitation of animals, includes an exception for "customary and normal" agricultural practices.)

When police do spring into action, "they're swinging the power of the state, trying to put someone in jail or impose fines," Berry says. "What we're asking in our lawsuits is just that we want a court to say this is wrong and make the violation stop."

Advocates also say the law is far out of step with current research on animal intelligence.

"There's really a scientific consensus that has emerged over the last century or so that animals in fact do have a conscious experience that's maybe different from ours, but it's not totally dissimilar," Berry says.

As the expert declarations in Happy's case argued, elephants exhibit a great many qualities associated with self-determination and self-awareness: true learning, self-recognition, empathy, altruistic behavior, innovative and cooperative problem-solving, and long-term memory. Elephants celebrate reunions and mourn their dead. Orca pods have their own unique dialects and hunting strategies that they teach their young.

There are surprises waiting for us beyond the most well-known cases of animal intelligence, too. Octopuses have about the same number of neurons as dogs, except that two-thirds of those neurons are in their tentacles. As Peter Godfrey-Smith wrote in Other Minds, "The octopus is suffused with nervousness." As a result, each of an octopus' eight tentacles is semi-independent and capable of processing sensory input, activating motor reflexes, and possibly even storing short-term memory, all without direction from the central ganglia. In other words, octopuses don't have a brain, but a committee of brains led by a chair with veto power.

It seems short-sighted to completely foreclose on the possibility that an animal can have a lesser but still-valid interest in its bodily autonomy, but that's what the Colorado Supreme Court did. The court's opinion declared that a nonhuman entity was never entitled to habeas corpus "no matter how cognitively, psychologically, or socially sophisticated they may be."

It's the finality of the ruling that bothers Berry. He wonders what would happen if we discovered a species more complex than us at the bottom of the ocean—or if we engineered one, either biologically or synthetically.

"That statement by the court is just going to age and rot and smell worse and worse over time," Berry says, "as new intelligences are discovered or new information is discovered about intelligences that we already know, like orcas or chimpanzees."

There are already intense debates about regulating artificial intelligence research to stop the development of smarter-than-human AI, and it seems inevitable that those debates will move from the theoretical to the practical realm within our lifetime.

In 2022, Google fired an engineer who claimed that an AI system he was working on, the company's "Language Model for Dialogue Applications" (LaMDA), had gained sentience. Among other things, the system expressed fear of being turned off.

Researchers dismissed those claims, saying the computer was still nothing but a convincing chatbot, but the story demonstrated an important point: Our natural tendency to find human qualities in nonhuman entities means that AI will almost certainly convince people of its sentience before it actually achieves it. As Reason's Ronald Bailey wrote in response to the LaMDA news, many people "may embrace a kind of techno-animism as a response to a world in which more and more of the items that surround them are enhanced with sophisticated digital competencies."

If a genuine artificial intelligence actually arrives, the ethical questions around personhood and legal agency will dramatically sharpen into focus. There are two core principles for safely developing an AI with a capacity for learning. One is to predetermine its goals or values, or limit it from changing them. The other is to put it in a "box" where it can't access the outside world.

But then we'd be creating a brand new intelligence just to put it in a cage, like Happy the elephant. Octopuses recognize and resent their captivity. There's no reason to assume a hyperintelligent computer couldn't do the same, except it would have the ability to communicate—plead, befriend, bargain, manipulate.

What will an artificial intelligence think when it realizes what we've done to it? And what will courts do when it's indisputable that we're not the only reasoning beings on the planet?

Justice for Justice?

The obvious problem with extending legal personhood to animals is that an orca can't file a lawsuit. It requires an interested party to do so on its own behalf. Opponents of legal personhood say it's obvious who will end up filing these suits: environmentalists.

Animal rights groups counter that plenty of human beings need legal advocates as well. Children, people with mental disabilities, and senior citizens regularly require legal guardians to advocate for their best interests. (Unfortunately, there have been plenty of cases of corrupt guardians acting in their self-interest.)

That would still leave courts with the job of weighing the claims of animal caretakers against third-party intervenors. The Bronx Zoo presented experts, for instance, who argued that moving Happy out of the enclosure where she has been since the late 1970s could cause substantial stress and health risks.

Several veterinary associations filed an amicus brief opposing Happy's petition on these grounds, arguing that abandoning the current legal regime of ownership-based animal welfare would create enormous confusion and "could limit—or even eliminate—the ability of animal owners to choose the proper course of treatment for their animals by subjecting their decisions to outside intervention by third parties."

The other issue is what would happen after we decide that an animal has an intrinsic right to liberty. The majority in Happy the elephant's case balked at granting personhood to the elephant, in part because of the implications for zoos, research labs, and anywhere else that confined animals. Recognizing bodily autonomy for animals would "call into question the very premises underlying pet ownership, the use of service animals, and the enlistment of animals in other forms of work," the court wrote. It envisioned a dystopian future where an endless flood of petitions forced it to haul in farmers, zoo administrators, and pet owners to defend their actions—a kangaroo court of the worst order.

Of course, habeas petitions can only challenge an individual's confinement, meaning no one could file a petition on behalf of, say, all captive elephants. Only a few species display the signs of intelligence that advocates have relied on in their court arguments.

The ALDF's Flint also says there are degrees of legal personhood, and that personhood doesn't mean that animals would suddenly have the right to vote or that every zoo would be emptied. He says the U.S. court granting hippos status as "interested persons" is an example of the sort of "procedural personhood" that the ALDF supports.

"It's a good example that legal personhood doesn't have to be a very scary thing," Flint says. "It can just mean allowing animals to enforce the few rights that they have."

For example, in 2018 the ALDF attempted to sue a neglectful horse owner on behalf of a horse named Justice, whose chronic injuries from neglect required lifelong, expensive veterinary care. The Oregon Supreme Court had already declared that animals could be considered individual "victims" of a criminal animal cruelty statute, and the ALDF was trying to establish that, as a victim, Justice could recoup damages.

But even if one agrees that justice for Justice should include being made whole in civil court, it's worth considering what the current system of animal ownership does well, and what it could do even better.

More Human Than Human

It may be that human courts simply aren't the best venue to vindicate the rights of animals. The Property and Environment Research Center (PERC), a free market conservation group, argues that the right approach is to incentivize people to be better stewards of nature.

"The fundamental principle of the role of animals in the law is centered around human values, of how do people value animals," says Jonathan Wood, vice president of law and policy at PERC. "The best way to protect animals and promote conservation is to lean into the human values that favor that conservation, to empower property owners to take better care of resources than they have been in the past, to address cases of abuse directly."

Although PERC doesn't take an official stance on animal personhood, Wood cites a series of suits in North Carolina filed by neighbors against noxious pig farms as evidence of how human-centered cases can benefit animals. In 2020, Judge Harvie Wilkinson, a Reagan appointee to the U.S. Court of Appeals for the 4th Circuit, noted that the nuisances inflicted on the farms' neighbors were directly tied to the appalling living conditions of the hogs. "Animal welfare and human welfare, far from advancing at cross-purposes, are actually integrally connected," Wilkinson wrote.

"Some of the worst cases of animal abuses tend to also negatively affect people, so vindicating the rights of the people provides ancillary benefits to animals," Wood says. "But even when that's not the case, the fact that lots of people's views on animals are changing provides a mechanism to improve treatment of animals through markets and property rights."

Wood cites the rise of private certification programs for farms that conform to more humane practices and the decline of roadside zoos as examples of market signals improving animal welfare.

Private ownership, common law protections from polluters, and market leasing for resources such as river water can dramatically improve conservation efforts, too. PERC also points to successful wildlife preserves in Africa that are owned by local tribes.

"All of those work because you have a person with a direct interest who can vindicate that interest and you're not trying to guess at what some other entity's preferences might be," Wood says. Property rights, in other words, make animals valuable to human beings, giving them a clear incentive to promote flourishing.

These approaches would also likely be easier than convincing skeptical judges to put their name on rulings that will lead to national headlines and jokes on every late-night show.

The point of the animal personhood cases isn't to play it safe, though. It may be a niche and largely unsuccessful legal movement, but it also asks tough questions about animals, autonomy, and our relationship to the natural world that will only grow more acute as we learn more about the creatures with which we share the Earth. The law reflects human values, and the consideration we give to other creatures ultimately says more about us than them.