Too hot for grazers: the effect of climate change on the distribution of medium-sized grazers

S. de Bie, H.H.T. Prins, A.K. Shrestha, S.E. van Wieren

Research output: Chapter in Book/Report/Conference proceedingAbstract


Body size matters and according to Bergmann’s rule species of larger size are found in colder environments and species within the same genus but of smaller size, in warmer areas. To understand the adaptive capacity of blue wildebeest in response of a changing climate, we investigated the variation in core body temperature (Tb) using abdominally implanted thermal loggers in two climatically different areas in South Africa. Wildebeest in the hot, dry savanna environment(less seasonal and mild winter) showed a higher variability in the 24-hour Tb amplitude and a lower minimum Tb during winter and spring than wildebeest in the area with a more seasonal, cold and long winter.This variation in Tb amplitude was positively correlated with the amplitude of ambient temperature and negatively with rainfall. We conclude that this larger variation in 24-hour amplitude and lower minimum Tb are the result of nutritional stress experienced by wildebeest in the hot environment: because of less available quality forage, animals are less able to maintain their body temperature. We predict that when climate in Africa become hotter and drier, medium-sized grazers are likely to be affected in terms of reproduction and distribution. For larger grazers, nutritional thresholds are lower while smaller grazers are more selective due to their narrow muzzles. Consequently both categories are able to better cope with the changing climate than medium-sized grazers as they are able to meet their nutritional requirements. This should have implications for long-term conservation of such species in Southern African national parks.
Original languageEnglish
Title of host publication12th Savanna Science Network Meeting, Kruger National Park, 9-13 March 2013, Skukuza, South Africa
PublisherSouth African National Parks, Scientific Services
Publication statusPublished - 2014
Event12th Savanna Science Network Meeting, Skukuza, South Africa -
Duration: 10 Mar 201414 Mar 2014


Conference12th Savanna Science Network Meeting, Skukuza, South Africa


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