Wildebeest muscles have an extremely high efficiency of 62.6%, meaning that almost two thirds of the energy used by the muscles appears as useful work in the form of movement rather than as wasteful heat. By comparison, most animal muscles and a car engine are only 25% efficient.
These findings come from research conducted by a team from the Royal Veterinary College’s (RVC) Structure & Motion Laboratory, who travelled to Botswana to examine how wildebeest are famously able to undertake long-range travel in arid conditions with little to no food or water.
In Botswana’s Makgadikgadi National Park there is only one water source in the dry season, the Boteti river, but the best grazing grounds are located 15km-30km away. The RVC’s team, led by Professor Alan Wilson, attached GPS tracking collars equipped with environmental sensors to 20 blue wildebeest to determine how the wildebeest tackle this challenge. Tiny muscle samples, less than 1mm across and 10mm long were also taken from the sedated wildebeest and electrically stimulated to assess the efficiency of the muscle.
From the collar data, Professor Wilson’s team found that wildebeest can go up to five days between visits to the river and walk up to 80km in that period, which enables them to spend most of their time eating the high-quality grass. Their strikingly high muscle efficiency rate is essential to enabling this.
The researchers found that the wildebeest continued this behaviour even when the daily temperature exceeded 40 degrees Celsius. In these conditions the wildebeest must sweat or pant to lose the heat created by locomotion, losing water in the process. Having more efficient muscles means less heat is produced and the wildebeest can conserve water, enabling them to last longer before having to drink again.
As wildebeest live on a nutritional and thermoregulatory knife-edge which could see them severely affected by climate change, this physiological adaptation may prove to be critical to their survival, particularly as it is predicted that Southern Africa will see higher temperatures and less reliable rainfall.
Commenting on the findings of the study, Professor Alan Wilson said:
“Carrying out complex laboratory measurements on wildebeest muscles in the African savannah was a physically challenging and technically complex task that produced striking findings. It was not known that wildebeest can travel for such long distances through hot regions without access to water, and we were surprised to discover just how energy-efficient their muscles are. The results of our study have helped inform how climate change will impact the nomadic lifestyle of these creatures.”
The RVC’s paper, ‘Remarkable muscles, remarkable locomotion in desert dwelling wildebeest’, has been published in Nature.