Court denies reconsideration in landmark chimpanzee rights case, leaving intact a ruling that invoked an 18th-century, biblically rooted conception of human dominion over animals despite extensive scientific evidence from the late Dr. Jane Goodall and other world-renowned chimpanzee experts
LANSING, Mich. — The Michigan Supreme Court denied the Nonhuman Rights Project’s motion for reconsideration in its landmark habeas corpus case on behalf of seven chimpanzees confined at the DeYoung Family Zoo, leaving intact a published Court of Appeals opinion that relied in part on an 18th-century conception of humans’ “sole and despotic dominion” over animals.
In reaching that conclusion, the Court turned to English jurist William Blackstone’s Commentaries for his description of property, which he defined as mankind’s “sole and despotic dominion” over external things, including animals. Blackstone rooted this definition in the Book of Genesis.
The DeYoung Family Zoo opposed the NhRP’s motion for reconsideration, asserting that chimpanzees inherently lack self-determination and their interests cannot be discerned by humans, and that this supports the theological concept of despotic dominion. This startling assertion was made despite an extensive scientific record in the case that includes submissions by some of the world’s foremost authorities on chimpanzee cognition and behavior, including the late Dr. Jane Goodall, Dr. Tetsuro Matsuzawa, the late Dr. Christophe Boesch, Dr. Jennifer Fugate, Dr. William McGrew, and Dr. Mary Lee Jensvold.
Drawing on more than 60 years of studying chimpanzees, Dr. Goodall explained that they possess individual personalities, intelligence and emotions, live in highly complex societies, and are autonomous beings with a highly complex cognitive nature. Other experts detailed chimpanzees’ sophisticated physical, psychological and social needs and the serious harm that can result when captivity prevents them from exercising autonomy.
Dr. Mary Lee Jensvold, a chimpanzee communication and behavior expert, specifically concluded that keeping the DeYoung chimpanzees indoors throughout the Michigan winter is “extremely harmful to their physical and psychological well-being.” She found that the zoo cannot meet their complex needs and recommended transferring them to a GFAS-accredited sanctuary where they could exercise their autonomy.
“The Michigan Supreme Court had an opportunity to reconsider whether our legal system should continue to deny liberty to autonomous beings based on an 18th-century theological conception of ‘despotic dominion.’ It declined to do so,” said Elizabeth Stein, Litigation Director at the Nonhuman Rights Project. “Not only did the Court of Appeals inappropriately rely on scripture in reaching its decision but it also implicitly denied the irrefutable and overwhelming scientific evidence in the case: evidence establishing that chimpanzees are autonomous, cognitively complex beings with profound social, psychological, and physical needs. Michigan’s courts have left in place a doctrine rooted in the supposed absolute dominion of humans over other animals. Science has moved forward. Our understanding of chimpanzees has moved forward. It is time for the law to keep abreast of this momentum.”
The NhRP filed its case in 2023, asking, through a writ of habeas corpus, for the chimpanzees’ right to liberty to be recognized and for them to be transferred to an accredited chimpanzee sanctuary. The trial court denied our complaint without a hearing, and the Michigan Court of Appeals affirmed the denial in October 2025.
The NhRP then sought to appeal the appellate court’s opinion to the Michigan Supreme Court, but the Court declined to hear the appeal on July 17, 2016. Justice Elizabeth Welch dissented from that decision, writing that our case raises “profound questions about bodily autonomy” and emphasizing the capacity of the common law to evolve alongside scientific understanding. The NhRP sought reconsideration, which the Supreme Court denied on September 17 without further substantive explanation.
The ruling leaves the seven surviving chimpanzees at the DeYoung Family Zoo without legal recourse to challenge their unjust confinement.