Recent findings from a new database tracking African hippo populations have exposed significant gaps in our understanding of where these large herbivores are found and thrive. Many populations are isolated and depend heavily on designated protected areas.
According to the International Union for the Conservation of Nature (IUCN) Red List, hippos are listed as “vulnerable to extinction.” They have often been referred to as “neglected megafauna,” receiving considerably less scientific study and research compared to other large mammals.
Hannah Lacy, a postgraduate researcher from the University of Leeds School of Biology, has created a spatial database that includes distribution and population estimates for common hippos in southern Africa. Her work has revealed significant data gaps regarding hippo populations in the region, with some areas completely lacking population estimates.
Moreover, the use of varying survey methods in different countries and regions has made tracking populations less effective. Disparities in funding among African nations have contributed to inconsistencies in data collection. In many instances, hippos were noted as minor observations while researchers focused on other animals, leading to incomplete data.
Ms. Lacy stated, “It’s tough to plan effective protection for hippos without trustworthy data on their habitats and population health.”
She emphasized the need for a centralized spatial database and coordinated surveys to enhance the conservation of common hippos, which play a vital role as ecosystem engineers in southern Africa.
As semi-aquatic creatures, hippos contribute uniquely to their ecosystems, aiding other local wildlife. Their feeding behavior influences the growth of vegetation along waterways, and their waste enriches aquatic food chains, benefiting species such as fish and invertebrates. In many areas, they are also a key attraction for eco-tourism, which supports local economies and livelihoods. Despite their ecological, social, and economic significance, common hippos are facing numerous threats primarily due to human activities.
Over the past century, hippo populations have suffered greatly from habitat destruction, poaching, and human-wildlife conflict. Current rough estimates place their numbers between 60,000 and 87,000 in southern Africa, making precise data on their habitats and population densities—like geographic range maps—essential for effective conservation measures.
The study revealed that known hippo populations frequently depend on cross-border protected areas known as Transfrontier Conservation Areas (TFCAs), highlighting the critical nature of international cooperation for successful conservation initiatives.
While these protected regions offer vital habitats for hippos, populations separated from others and breeding within limited genetic pools risk becoming genetically isolated.
Ms. Lacy’s research, published in the journal Biological Conservation, examined nearly 200 data records from nine southern African countries: Angola, Zimbabwe, Zambia, Malawi, Mozambique, Botswana, Namibia, South Africa, and Eswatini. This data included information from other studies, government reports, charities, online resources, and aerial surveys from 2003 to 2023.
She is now advocating for collaborative surveys and a centralized database to enhance hippo conservation efforts and outcomes in the region. A similar initiative, the African Elephant Database managed by the IUCN African Elephant Specialist Group, has proven essential for safeguarding elephant populations across Africa.
Dr. Lochran Traill, Ms. Lacy’s PhD supervisor, supported her findings, asserting, “This work updates our knowledge of common hippo distribution in southern Africa and underscores the extent of population fragmentation and isolation. We hope this information aids conservation policymakers.”
