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Animal Personhood Considerations: Populating, Populating Hippos

Written by Skylar Steel, Fall 2021 Wildlife Law student under Carol Frampton at Michigan State University College of Law

Granting animals legal personhood status has been a long, unsuccessful road for animal rights activists in the United States. American law has long established that animals are considered property and, therefore, do not have many legal rights and protections.[1] Legal personhood typically refers to a human or non-human entity that, under the law, has legal standing to sue or be sued in a court of law.[2]

Descendants of Pablo Escobar’s hippopotamuses have made U.S. history by being the first animals to receive recognition as legal persons in the U.S. by any court- though only as the U.S District Court for the Southern District of Ohio’s acknowledgement of foreign law.[4] The Animal Legal Defense Fund (ALDF) asked the U.S. District Court for the Southern District of Ohio to review relevant documents in response to an ongoing lawsuit in Colombia regarding these animals.[5] ALDF filed an application to the court under a federal statute that governs assistance to foreign courts.[6] The statute allows any “interested person” in a foreign lawsuit to request a federal court to take U.S. depositions in support of a foreign litigation.[7] An interested person is “[a] person having a property right in or claim against a thing.”[8] The U.S. Supreme Court has held there is “no doubt” that one of the parties to the foreign lawsuit, whether a plaintiff or defendant, qualifies as an “interested person” for purposes of this statute.[9] Therefore, ALDF was confident that since the hippos are the named plaintiffs in the Colombian lawsuit, they would meet the definition of “interested persons” under the statute.[10]

Colombia Lawsuit

In 1993, when Pablo Escobar was killed, Colombian officials left his four illegally imported hippopotamuses at his estate.[11] These animals broke free of Escobar’s property, migrated to the Magdalena River, and now have repopulated to over 80 hippos.[12] Officials considered killing the hippos due to the negative impact they have had on its ecosystem.[13] In July, 2020, Luis Domingo Gómez Maldonado, a Colombian animal rights attorney, filed suit in Colombia on the hippos’ behalf to prevent them from being killed.[14] Colombia law grants animals legal standing to bring lawsuits to protect their wellbeing.[15] Thus, the hippos are the plaintiffs in the Colombian lawsuit brought by the animal rights attorney. He is seeking a court order to provide a contraceptive, porcine zona pellucida (PZP), to the hippo population instead of killing them.[16] PZP has a long history of success in captive hippos and is recommended by an international organization that focuses on the sterilization of various species.[17]

On October 15, 2021, Colombian authorities announced that some of the hippo population had started to be treated with a contraceptive called GonaCon.[18] However, there is concern over its safety and effectiveness, and it is unclear how many hippos the authorities still intend to kill.[19]

United States’ Involvement

ALDF filed the application on behalf of the “Community of Hippopotamuses Living in the Magdalena River” in the district court on October 15, 2021.[20] It requested the court grant the application to subpoena Dr. Elizabeth Berkeley and Dr. Richard Berlinski to testify in support of the ongoing Colombia litigation.[21] If granted, the court could hear the testimony of these two wildlife experts regarding the use of contraceptives to prevent this population of hippos from continuing to reproduce.[22] The application included the urgency that “[w]ithout such evidence, the [hippos] are likely to be killed” by Colombian officials.[23] The application also discussed how all requirements of the applicable statute were met because the doctors to be deposed as witnesses both resided in the district in which the application was filed, and their testimony would be “for use” in the foreign litigation in Colombia.[24] Because the matter was time-sensitive, the application was filed ex parte, meaning the other party, in this case, the Colombian officials, were not given notice of the application[25]

On October 15, 2021, the same day the application was filed, the court granted the application and authorized ALDF to issue subpoenas to the wildlife experts.[26] The court also held it will maintain jurisdiction over the matter, meaning it will be the court to hear the depositions for the Colombian case.[27] Because the application was submitted on behalf of the hippos as the “interested persons” of the foreign lawsuit, in granting the application, the court recognized these hippos as legal persons for purposes of the statute.[28] ALDF planned to depose the wildlife experts to hear their testimony in support for the use of the PZP contraceptive, which will safely prevent this hippo population from procreating, negating the need to kill them.[29] However, within a few weeks, as of February 22, 2022, Colombia’s government “plans to sign a document declaring the hippos an exotic invasive species” and coming up with a plan to control the population. [30]


[1] See Lauren M. Sirous, Comment: Recovering for the Loss of a Beloved Pet: Rethinking the Legal Classification of Companion Animals and the Requirements for Loss of Companionship Tort Damages, 163 U. Penn. L. Rev. 1199, 1205-06 (2015) (discussing how U.S. laws have historically viewed animals as “things” that are valuable and useful for humans to obtain ownership over and as the owner’s personal property). [2] See Jon Garthoff, Corporations, Animals, and Legal Personhood, Scholars Strategy Network (May 30, 2018), [3] Photo from Pablo Escobar: Colombia's 'cocaine hippos' must be culled, scientists say - CNN. [4] Garthoff, supra note 435. [5] Id. [6] See 28 U.S.C. § 1782. [7] Id. [8] Interested Person, Black’s Law Dictionary (11th ed. 2019). [9] Intel Corp. v. Advanced Micro Devices, Inc., 542 U.S. 241, 256 (2004); see § 1782. [10] Press Release, Animal Legal Defense Fund, Animals Recognized as Legal Pers. for the First Time in U.S. Ct. (Oct. 20, 2021) [11] See David Moye, Court Rules Pablo Escobar’s Cocaine Hippos Are Legally People, Huff Post (Oct. 21, 2021), [12] Id. [13] Id. [14] Id. [15] Id. [16] See Press Release, Animal Legal Defense Fund, supra note 443. [17] Id.; see J.F. Kirkpatrick, A. Rowan, N. Lamberski, R. Wallace, K. Frank & R. Lyda, The Practical Side of Immunocontraception: Zona Proteins and Wildlife, 83 J. Reprod. Immunology 151, 152 (2009) (discussing how PZP has been a very successful contraceptive for 80 different species of mammals, including hippos, both free-ranging and captive). [18] See Press Release, Animal Legal Defense Fund, supra note 443. [19] Id. [20]S.D. Ohio Ex Parte Appl. of Community of Hippopotamuses Living in the Magdalena River for an Order Pursuant to 28 U.S.C. § 1782 to Conduct Disc. for Use in Foreign Proceeding, 1, Oct. 15, 2021. [21] Id. [22] Id. [23] Id. [24] Id. [25] Id.; see Ex Parte, Black’s Law Dictionary (11th ed. 2019). [26] S.D. Ohio Order Granting Appl. to Issue Subpoenas for the Taking of Deps. Pursuant to 28 U.S.C. § 1782, 1, Oct. 15, 2021. [27] Id. [28] See Press Release, Animal Legal Defense Fund, supra note 443. [29] Id. [30] CBS News, Colombia plans to declare Pablo Escobar’s “cocaine hippos” an invasive species. Many locals worry the plan could harm the animals. February 22, 2022.


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