Human population growth and environmental pressures, including habitat loss and fragmentation, are driving severe declines in global biodiversity. Rhinoceroses are particularly impacted by habitat loss and poaching for rhino horn, with wild populations rapidly decreasing. The black rhinoceros has declined by 97.6% due to poaching, the northern white rhinoceros is functionally extinct with only two females remaining under protection, and the southern white rhinoceros, though once recovered, now faces renewed threats to its survival.
Protecting rhinoceros populations in their natural habitats is central to conservation, aiming for growth through natural breeding. Yet, closed populations face challenges with genetic diversity, traditionally addressed by translocation of unrelated individuals—a process that is often complex, costly, and risky (see below).
Preserving viable gametes, embryos, and tissues from living and deceased animals enables assisted reproductive technologies (ART) like artificial insemination and embryo transfer, enhancing genetic diversity without moving animals. While ART in wildlife requires species-specific protocols and faces logistical challenges, successful rhinoceros births from AI in captivity show its promise.
With wild populations declining, urgent action is needed NOW to collect and preserve viable biomaterials. Establishing genetic repositories now is vital for the resilience and future recovery of rhinoceros populations.
Why Assisted Reproduction (ART)?
Protecting rhinoceros populations in their natural habitats remains the cornerstone of conservation efforts, with the ultimate goal of promoting population growth through natural breeding. However, maintaining closed populations long-term presents significant challenges. Genetic enrichment is essential to prevent inbreeding and loss of diversity. Traditionally, this has been achieved by introducing unrelated individuals through translocation. While effective in theory, translocations are often logistically complex, costly, and pose health risks for the animals concerned. They are also typically limited to small numbers and may reduce reproductive success due to the stress of relocation and the need for animals to adapt to unfamiliar environments.
An alternative solution lies in the preservation of reproductive material—viable gametes (oocytes and sperm), embryos, and tissues—from both living and deceased individuals. These materials can be used in assisted reproductive technologies (ART) such as artificial insemination and embryo transfer to enhance genetic diversity without physically relocating animals. These methods also offer the potential to extend the reproductive lifespan of individuals and preserve genetics beyond their natural breeding years.
However, the successful application of ART in wildlife requires the development of species-specific protocols and tools, tailored to the unique reproductive anatomy and physiology of each species. Unlike in domestic animals, where research benefits from large, accessible populations, progress in wildlife species has been slow due to limited access to individuals, logistical challenges, and high costs. Despite these barriers, promising outcomes—such as rhinoceros births following AI with both fresh and frozen semen in captivity—demonstrate the potential of these techniques.
As wild rhinoceros populations continue to decline and threats persist, it is critical to act NOW! The opportunity still exists to collect and preserve viable biomaterials from a meaningful number of individuals. Establishing genetic repositories today will be essential to support the resilience and long-term recovery of rhinoceros populations in the future.
Hemmersbach Rhino Force 