How Do Springbok Keep Cool?

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Springbok (Antidorcas marsupialus) live in South Africa which, obviously, can get very hot during the day. Many animals that live in Africa tend to try and stay in the shade during the day to keep cool but there are also those that store heat in their body during the day and then let their body temperature decrease rapidly during the night so that the next day they can do the same again. This technique is called adaptive heterothermy and has been seen in often in captive animals. Fuller et al (2005) carried out a study to see whether this technique was also found in wild animals and decided to investigate a free ranging herd of Springbok.

For this study some very impressive technology was used to save time and also to make the results more accurate. Small data recorders where implanted inside each animal and these measured the body temperature of the animals every 30 minutes for a year. If this technology had not been used then the Springbok would have had to have been captured every 30 minutes, every day for a year. Not only would this be very time consuming, it would also affect the results of the study because the animals would likely be stressed about being caught all the time. While the animals were doing their own thing for a year, the team measured the temperature of the air, the wind speed and the humidity so that at the end of the year the body temperature could be compared with the weather.

If the Springbok used the technique described above then the body temperature would be expected to change often with very wide swings. They actually found that the opposite happened. No matter what the weather was like, the body temperature of the animals hardly changed. This technique is called homeothermy and it was a very surprising find. Even stressful events like giving birth did not affect the body temperature a great amount.

This study highlighted a very important point to consider when carrying out experiments on body temperature. When animals are roaming free in their natural environment they often use behavioural mechanisms to change body temperature instead of using physiological mechanisms such as adaptive heterothermy. Behavioural mechanisms like this include huddling together when it is cold or finding a shady area when it is too warm. Fuller and team made a mistake in this study because they did not watch the behaviour of the animals, they only took physiological measurements. Hopefully further studies will be carried out that will learn from this mistake!

References

Fuller, A., Kamerman, P. R., Maloney, S. K., Matthee, A., Mitchell, G. and Mitchell, D. (2005). A year in the thermal life of a free-ranging herd of springbok Antidorcas marsupialis. J. Exp. Biol. 208, 2855-2864.