Hippopotamus (H. amphibius) diet change indicates herbaceous plant encroachment following megaherbivore population collapse.
Megaherbivores (>1000 kg) are critical for ecosystem health and function, but face population collapse and extinction globally. The future of these megaherbivore-impoverished ecosystems is difficult to predict, though many studies have demonstrated increasing representation of C3 woody plants. These studies rely on direct observational data, however, and tools for assessing decadal-scale changes in African ecology without observation are lacking. We use isotopic records of historical common hippopotamus (Hippopotamus amphibius) canines to quantify herbaceous vegetation change in Queen Elizabeth National Park, Uganda following a period of civil unrest and poaching. This poaching event led to population collapse of two threatened African megaherbivore species: hippopotamus and African elephants (Loxodonta africana). Serial carbon isotope ratios (δ(13)C) in canine enamel from individuals that lived between 1960-2000 indicated substantial increases in C3 herbaceous plants in their diet (<20% C3 in the 1960s to 30-45% C3 in the 80s and 90s), supported by other observational and ecological data. These data indicate megaherbivore loss results in succession of both woody and herbaceous C3 vegetation and further reaching effects, such as decreased grazing capacity and herbivore biodiversity in the area. Given multiple lines of evidence, these individuals appear to accurately capture herbaceous vegetation change in Mweya.
Global Change and Sustainability Center, University of Utah, Salt Lake City UT, USA.
Kendra L
KL
Chritz
Department of Anthropology, Graduate Center, City University of New York, New York NY, USA.|New York Consortium in Evolutionary Primatology, New York NY, USA.|Department of Geology and Geophysics, University of Utah, Salt Lake City UT, USA.
Scott A
SA
Blumenthal
Global Change and Sustainability Center, University of Utah, Salt Lake City UT, USA.|Department of Geology and Geophysics, University of Utah, Salt Lake City UT, USA.
Thure E
TE
Cerling
Zoologisches Institut, Universitaet Braunschweig, Braunschweig Germany.
Hans
H
Klingel
D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D001188:Artiodactyla / Q000502:physiology*; D002247:Carbon Isotopes / Q000032:analysis; D003481:Cuspid / Q000737:chemistry*; D017753:Ecosystem; D004606:Elephants / Q000502:physiology*; D053476:Extinction, Biological; D060434:Herbivory; D011159:Population Surveillance; D014454:Uganda
D002247:Carbon Isotopes