Studies to reveal correlation between terrain, energy use and giraffe locomotion

Photo: Supplied.

More than half of giraffes in captivity in Europe are afflicted by lameness. This high prevalence represents an important welfare issue, similar to other large zoo animals.

Veterinarian at the Royal Veterinary College in the United Kingdom (UK), Dr Chris Basu, says giraffes in captivity are often afflicted by overgrown hooves, laminitis and joint problems.

Diagnosis and treatment is limited by our understanding of anatomy and function, more specifically the locomotion of these animals.

Although the giraffe is such a well-known and iconic animal, relatively little has been studied about their locomotor behaviour.

Basu recently visited South Africa to do fieldwork on the locomotion of giraffes as part of his PhD studies under the mentorship of world-renowned Professor of Evolutionary Biomechanics, John Hutchinson.

This project is a joint venture between Basu and Francois Deacon, a researcher in the Department of Animal, Wildlife, and Grassland Sciences at the University of the Free State (UFS). Deacon is a specialist in giraffe habitat-related research.

Together Hutchinson and Drs Deacon and Basu form a research group, working on studies about giraffe locomotion.

“Locomotion is one of the most common animal behaviours and comes with a significant daily energetic cost. Studying locomotion of wild animals aids us in making estimates of this energetic cost. Such estimates are useful in understanding how giraffes fit into ecosystems. Future conservation efforts will be influenced by knowledge of the energy demands in giraffes.

“Understanding aspects of giraffe locomotion also helps us to understand the relationships between anatomy, function and evolution. This is relevant to our basic understanding of the natural world, as well as to conservation and veterinary issues,” said Dr Deacon.

On face value it seems as if foot disease pathologies are more common in zoo giraffes than in wild giraffes.

“However, we need a good sample of data from both populations to prove this assumption,” said Basu.

This phenomenon is not well understood at the moment, but it’s thought that diet, substrate (e.g. concrete, straw, sand and grass) and genetics play a part in foot disease in giraffes. “Understanding how the feet are mechanically loaded during common activities (standing, walking, running) gives our research group ideas of where the highest strains occur, and later how these can be reduced through corrective foot trimming,” said Basu.

Through the studies on giraffe locomotion, the research group plans to devise strategies for corrective foot trimming. At the moment, foot trimming is done with the best evidence available, which is extrapolation from closely related animals such as cattle.

“But we know that giraffes’ specialist anatomy will likely demand specialist foot care,” Basu added.

The research group has begun to study the biomechanics of giraffe walking by looking at the kinematics (the movement) and the kinetics (the forces involved in movement) during walking strides. For this he studied adult giraffes at three zoological parks in the UK.

However, due to the close proximity of fencing and buildings, it is not practical to study fast speeds in a zoo setting.

A setting such as the Willem Pretorius Nature Reserve, near Ventersburg in the Free State, Kwaggafontein Nature Reserve, near Colesberg in the Karoo, and the Woodland Hills Wildlife Estate in Bloemfontein are all ideal for studying crucial aspects such as “faster than walking” speeds and gaits to measure key parameters (such as stride length, step frequency and stride duration). These studies are important to understand how giraffe form and function are adapted to their full range of locomotor behaviours. It also helps to comprehend the limits on athletic capacity in giraffes and how these compare to other animals.

The increasing availability of unmanned aerial vehicles (UAVs)/drones opens up unique opportunities for studying locomotion in animals like giraffes. Cameras mounted onto remotely controlled UAVs are a straightforward way to obtain high-quality video footage of giraffes while they run at different speeds.

“Using two UAVs, we have collected high definition slow motion video footage of galloping giraffes from three locations in the Free State. We have also collected detailed information about the terrain that the giraffes walked and ran across. From this we have created 3D maps of the ground. These maps will be used to examine the preferred terrain types for giraffes, and to see how different terrains affect their locomotion and energy use,” said Deacon.

“The raw data (videos) will be digitised to obtain the stride parameters and limb angles of the animals. Later this will be combined with anatomical data and an estimation of limb forces to estimate the power output of the limbs and how that changes between different terrains,” said Basu.

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