University of Pretoria and BVC work together to advance giraffe research

More than 10 year of fruitful giraffe research by the Centre for Veterinary Wildlife Studies (University of Pretoria) thanks to the Bubye Valley Conservancy.

Since 2006, the Bubye Valley Conservancy (BVC) has been an integral part of the Centre for Veterinary Wildlife Studies’ (CVWS) giraffe research project. During this time the CVWS, which falls under the Faculty of Veterinary Science at the University of Pretoria, has produced groundbreaking giraffe research which has drawn the attention of academics and popular media alike. 

The giraffe’s body form makes it an interesting animal to study adaptation to body shape as well as the possible evolutionary drivers that may have given rise to such an extreme shape. Although only giraffe cardiovascular, respiratory and skeletal physiology were the initial focus areas of the research, the project has since expanded to include gastrointestinal and head and neck morphophysiology, in addition to a side project on wildebeest anatomy and physiology. To date, the BVC giraffe database has directly given rise to over ten publications on giraffe morphology, digestive, cardiovascular and respiratory morphophysiology, as well as giraffe evolution, growth and palaeontology (Mitchell & Skinner, 2009; Mitchell, Van Sittert & Skinner, 2009a,b, 2010; Van Sittert, Skinner & Mitchell, 2010; Mitchell & Skinner, 2011; Mitchell et al., 2013a,b; Mitchell, Roberts & Van Sittert, 2015; Van Sittert & Mitchell, 2015; Van Sittert, Skinner & Mitchell, 2015).

 
 

One of the groundbreaking findings to arise from the BVC giraffe project was a rebuttal of the idea that sexual selection has led to the extraordinary long neck in giraffes (Mitchell, Van Sittert & Skinner, 2009a). The authors of the study found that female giraffes invest just as much into neck growth per kg body mass as males, a fact that makes sexual selection unlikely. This research has been well received and has even been reported on in the popular media (Switek, 2013).

Other significant findings of the BVC giraffe project include that giraffe neck growth starts at a disproportionate rate only after birth (Van Sittert, Skinner & Mitchell, 2010), that giraffes do not have a larger heart than expected for their body mass (also receiving attention in popular media, Bourton, 2009), explanations on how giraffes cope with the large respiratory dead space (Mitchell & Skinner, 2011) and a finding that showed that larger, longer giraffes were not the best survivors of a drought (Mitchell, Van Sittert & Skinner, 2010).

Under the leadership of Prof Graham Mitchell and the late Prof John Skinner, eight veterinary science students received first hand training in data collection and research methodology on site at the BVC. In addition, the project has led to the attainment of a PhD degree (Dr Brand van Sittert) under Professors Mitchell and Skinner’s supervision, while Dr David Roberts is currently enrolled for an MSc degree under Prof Mitchell.

Current and on-going projects of the CVWS at the BVC include investigations into the bone physiology and microstructure of giraffe long bones and growth patterns of the wildebeest cardiovascular and respiratory systems. These and other projects’ success can be directly attributed to BVC’s extraordinary support and commitment to research and those involved at the CVWS look forward to future fruitful collaborations.

References

Bourton J. 2009.BBC - Earth News - “Supercharged” heart pumps blood up a giraffe’s neck. Available at http://news.bbc.co.uk/earth/hi/earth_news/newsid_8368000/8368915.stm (accessed March 19, 2017).

Mitchell G., Roberts DG., Van Sittert SJ. 2015. The digestive morphophysiology of wild, free-living, giraffes. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 187:119–129.

Mitchell G., Roberts DG., Van Sittert SJ., Skinner JD. 2013a. Growth patterns and masses of the heads and necks of male and female giraffes. Journal of Zoology 290:49–57. DOI: 10.1111/jzo.12013.

Mitchell G., Roberts DG., Van Sittert SJ., Skinner JD. 2013b. Orbit orientation and eye morphometrics in giraffes (Giraffa camelopardalis). African Zoology 48:333–339.

Mitchell G., Skinner JD. 2009. An allometric analysis of the giraffe cardiovascular system. Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology 154:523–529.

Mitchell G., Skinner JD. 2011. Lung volumes in giraffes, Giraffa camelopardalis. Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 158:72–78. DOI: 10.1016/j.cbpa.2010.09.003.

Mitchell G., Van Sittert SJ., Skinner JD. 2009a. Sexual selection is not the origin of long necks in giraffes. Journal of Zoology (London) 278:281–286.

Mitchell G., Van Sittert SJ., Skinner JD. 2009b. The structure and function of giraffe jugular vein valves. South African Journal of Wildlife Research 39:175–180.

Mitchell G., Van Sittert SJ., Skinner JD. 2010. The demography of giraffe deaths in a drought. Transactions of the Royal Society of South Africa 65:165–168.

Switek B. 2013.Giraffe Necks Not for Sex – Phenomena. Available at http://phenomena.nationalgeographic.com/2013/01/15/giraffe-necks-not-for-sex/ (accessed March 19, 2017).

Van Sittert SJ., Mitchell G. 2015. On reconstructing Giraffa sivalensis, an extinct giraffid from the Siwalik Hills, India. PeerJ 3:e1135. DOI: 10.7717/peerj.1135.

Van Sittert SJ., Skinner JD., Mitchell G. 2010. From fetus to adult - an allometric analysis of the giraffe vertebral column. Journal of Experimental Zoology Part B Molecular and Developmental Evolution 314B:469–479.

Van Sittert SJ., Skinner JD., Mitchell G. 2015. Scaling of the appendicular skeleton of the giraffe (Giraffa camelopardalis). Journal of Morphology 276:503–516. DOI: 10.1002/jmor.20358.