Southern Africa is home to the majority of the world’s remaining black and white rhinoceros populations, with 80% and 92%, respectively. However, climate change is rapidly affecting the region due to global warming, and its impact on these rhino populations has been largely unexplored until recently. A team of researchers from the University of Massachusetts Amherst has just published a study in the journal Biodiversity, shedding light on the fact that rising temperatures pose a significant threat to rhinos in the area.
While traditional conservation efforts have primarily focused on combating poaching, the consequences of climate change on rhinos have not received sufficient attention. The study reveals that rhinos are particularly sensitive to increasing temperatures, which are expected to surpass their acceptable maximum threshold relatively quickly. Consequently, managers of national parks in the region need to begin planning and implementing adaptations to cope with rising temperatures to secure a future for these rhinoceroses.
Over the past century, the African continent has witnessed an average monthly temperature increase of 0.5 to 2 degrees Celsius, with projections indicating another two degrees of warming over the next 100 years under high greenhouse gas emissions scenarios outlined by the Intergovernmental Panel on Climate Change (IPCC).
Climate change is also disrupting historical precipitation patterns, raising the question of whether temperature or rainfall changes will have a more significant impact on rhino populations, which are vulnerable due to their inability to sweat and rely on methods like bathing and seeking shade to cool themselves.
Lead author Hlelowenkhosi S. Mamba emphasizes the importance of conducting large-scale macroecological assessments to predict and model the future of vulnerable species in the face of climate change. These assessments are crucial for conservationists to prepare and minimize global biodiversity losses.
To understand how climate change will affect rhino populations, Mamba and senior author Timothy Randhir, a professor of environmental conservation at UMass Amherst, focused their research on the five major national parks in South Africa, Namibia, Zimbabwe, Kenya, Botswana, Tanzania, and eSwatini, where most of the rhinos are found. These parks encompass diverse landscapes.
The researchers developed two scenarios for each park: the IPCC’s high-emissions scenario and a more moderate emissions scenario. They projected temperature and precipitation changes for each scenario up to 2055 and 2085 to assess the probability of each park remaining suitable for rhinos.
Their findings indicate that by 2055, each park will experience approximately 2.2°C of warming under the moderate emissions scenario and 2.8°C under the high emissions scenario. By 2085, the warming is projected to reach 2.5°C under the moderate emissions scenario and 4.6°C under the high emissions scenario. Furthermore, nearly all parks will become drier as emissions increase, except for Tsavo West National Park in Kenya, which will receive more rainfall.
These changes in temperature and precipitation are unfavorable for rhinos, with white rhinos being affected earlier than black rhinos. The authors note that “all the parks are showing drastic changes in the occurrence probability of rhinos,” and under the high-emissions scenarios, the probability of either species’ occurrence drops to zero by 2085.
The most concerning findings are related to Etosha National Park in Namibia and Hlane National Park in eSwatini, both of which are projected to become too warm for rhinos in either emissions scenario.
Despite the grim outlook, the study highlights the importance of using climate predictions for both park and rhino management. The authors suggest that park managers should consider strategies such as increasing water supplies, enhancing tree cover, monitoring rhino stress levels, and planning for rhino migration as the world continues to warm. These proactive measures are crucial for safeguarding the future of rhinoceros populations in Southern Africa.