Drug lord Pablo Escobar imported 4 Hippopotamuses (Hippopotamus amphibius) onto his private estate in Colombia in the 1980s. Since his arrest and assassination, the hippos have escaped the confines of the property and have begun to reproduce in the wild of Colombia. They now number approximately 60 individuals. The presence of such a large, and possibly dangerous, species in a new habitat raises several moral and ecological questions and dilemmas. It is unknown what effect these animals may have on their new environment, or the threat that they pose to the people living near them. In an effort to mitigate possible risks to the environment and local populations the Colombian government initiated an effort to castrate all males in the herd. However, it is unlikely that these efforts will be very effective in curbing the population growth of the animals. South America lost most of its large species of animals during the Quaternary Extinction and it is possible that the hippos are filling a gap that still exists in the ecology of the continent. The rewilding efforts occurring around the world aim to restore and protect natural processes and habitats by introducing (or reintroducing) apex predators or keystone species. Perhaps further research could shed light on possible positive influences that the Hippos have on the South American environment and responsible ways to avoid risks to local populations.
Australian Government Department of Sustainability Environment Water Population and communities. (2018). The Feral Water Buffalo (Bubalus bubalis). Retreived from: https://www.environment.gov.au/system/files/resources/b4a187ba-7a72-4ed2-ab06-7a8b8a1b87a0/files/buffalo.pdf.
BartlettL.J.WilliamsD.R.PrescottG.W.BalmfordA.GreenR.E.ErikssonA.ValdesP.J.S.J.S. and ManicaA.. (2015). Robustness despite uncertainty: regional climate data reveal the dominant role of humans in explaining global extinctions of Late Quaternary megafauna. Ecography39152–161.
DonlanC.J.BergerJ.BockC.E.BockJ.H.BurneyD.A.EstesJ.A.ForemanD.MartinP.S.RoemerG.W.SmithF.A.SouléM.E. and GreeneH.W.. (2006). Pleistocene rewilding: an optimistic agenda for twenty-first century conservation. The American Naturalist168660–681.
DoughtyC.E.RomanJ.FaurbyS.WolfA.HaqueA.BakkerE.S.MalhiY.Dunning Jr.J.B. and SvenningJ.C.. (2016). Global nutrient transport in a world of giants. Proceedings of the National Academy of Sciences113868–873.
DoughtyC.E.WolfA.Morueta-HolmeN.JørgensenP.M.SandelB.ViolleC.BoyleB.KraftN.J.B.PeetR.K.EnquistB.J.SvenningJ.-C.BlakeS. and GalettiM.. (2016). Megafauna extinction, tree species range reduction, and carbon storage in Amazonian forests. Ecography39194–203.
FriendG. and K.Cellier. (May 1990). Wetland and herpetofauna of Kakadu National Park, Australia: seasonal richness trends, habitat preferences and the effects of feral ungulates. Journal of Tropical Ecology6131–152.
JacquesH.J.Reed-Smith and M.J.Somers. (2015). Aonyx capensis. The IUCN Red List of Threatened Species 2015: e.T1793A21938767. http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T1793A21938767.en.
Keith DiagneL. (2015). Trichechus senegalensis (errata version published in 2016). The IUCN Red List of Threatened Species 2015: e.T22104A97168578. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T22104A81904980.en.
KingdonJ. (1988). East African Mammals: An Atlas of Evolution in Africa Volume 6 Part B: Large Mammals. University of Chicago Press. p. 77.
LambD.W.SaalfeldM.McGregorG.EdwardsB.Zeng and PetronellaVaarson-Morel. (2010). A GIS-based decision-making structure for managing the impacts of feral camels in Australia. The Rangeland Journal32 pp 129–143.
LewisonR. (2007). Population responses to natural and human mediated disturbances: assessing the vulnerability of the common hippopotamus (Hippopotamus amphibius). African Journal of Ecology45407–415
MalhiY.DoughtyC.E.GalettiM.SmithF.A.SvenningJ.-C. and TerborghJ.W.. (2016). Megafauna and ecosystem function from the Pleistocene to the Anthropocene. Proceedings of the National Academy of Sciences113838–846.
WernerP. (2005). Impact of feral water buffalo and fire on growth and survival of mature savanna trees: an experimental field study in Kakadu National Park, northern Australia. Austral Ecology30625–647.