New research from the University of Illinois Urbana-Champaign and Morfeld Research & Conservation highlights a concerning trend in the conservation of giraffes. Published in the Journal of Heredity, the study reveals that the genetic diversity of American giraffe collections has been compromised due to hybridization across different species. This development diminishes their potential role as “assurance populations,” which are crucial for the revival of critically endangered giraffe populations in the wild.
According to senior study author Alfred Roca, a professor in the Department of Animal Sciences, captive breeding programs must consider using fresh genetic stocks from the wild to preserve the integrity of assurance populations. “Wild giraffes cannot afford to lose their backups,” Roca emphasized, noting that the current population of approximately 97,500 giraffes across 21 African nations is already classified as vulnerable by the International Union for Conservation of Nature (IUCN).
Historically, giraffes were considered a single species with multiple subspecies, but recent DNA sequencing has identified four distinct species that do not typically interbreed. Earlier this year, the IUCN formally recognized all four species as vulnerable, with some populations classified as critically endangered. This knowledge is vital for effective conservation efforts, as it informs how biologists manage the unique needs of different giraffe populations.
Wesley Au, the study”s first author and a doctoral researcher at the University of Illinois, conducted a genetic analysis of 52 giraffes from various American facilities, including zoos and private ranches. The findings revealed that most of these giraffes do not represent a single species but rather a mixture of two or three species, with only eight individuals showing a 90% genetic match to one of the wild species.
Co-author Chris Fields, who leads the HPCBio core at Illinois” Roy J. Carver Biotechnology Center, remarked on the significance of using genomic data to inform conservation strategies. The research team discovered that a few individuals might trace their lineage to a wild reticulated giraffe that was a natural hybrid. This situation arose partly due to a 2004 policy by the Association of Zoos and Aquariums (AZA) to manage giraffe breeding as a single generic unit instead of maintaining separate programs for each subspecies.
Roca pointed out that the AZA”s decision was influenced by the extensive hybridization already present within the giraffe population at that time. However, the genetic diversity and origins of these animals became clearer only after subsequent studies.
Kari Morfeld, another co-author of the study, noted that breeding decisions in captive programs often prioritize animal temperament over genetic background. “We need to consider genetics, not just demeanor or physical traits, for better giraffe conservation,” Morfeld stated.
The researchers advocate for phasing out hybridized individuals from breeding programs, suggesting that some could still serve as valuable ambassadors for the species. They also propose screening for potential better genetic matches to wild populations within American collections. However, the authors caution that conservation efforts cannot solely rely on zoos and private collections; substantial investments are necessary to restore wild populations in Africa, many of which are nearing local extinction.
Morfeld acknowledges the logistical challenges of starting a breeding program with wild genetics, particularly in moving large animals across continents. She suggests that developing reproductive technologies, such as artificial insemination and embryo transfer, could be a more feasible solution. “There is no reason we cannot apply these methods to giraffes, as we do with livestock and other species,” she noted.
Establishing trust with African governments and conservation organizations is crucial for these initiatives to succeed. Morfeld concluded by highlighting the importance of ensuring that all stakeholders benefit from such conservation efforts.
For further details, refer to the study: Wesley C Au et al, “Genomic Assessment of Giraffes in North American Collections Highlights Conservation Challenges,” Journal of Heredity (2025). DOI: 10.1093/jhered/esaf089.
