Giraffes really struggle with slopes

In a perhaps unsurprising turn of events new research has found that giraffes, which aren’t known for their grace, prefer to remain on flatter ground.

In fact it revealed they flat-out refuse to climb slopes of more than 20°!

The research, which was presented at the British Ecological Society’s Annual Meeting in Liverpool last week and is yet to be published in a peer-reviewed journal, highlights a mismatch between giraffes’ ideal, flat habitats and the areas in which they are being conserved.  

It found that giraffes will tolerate some steepness to access food, but only up to 12° and only if it leads to favourable vegetation.

According to Jessica Granweiler, a PhD candidate at the University of Manchester in the UK, giraffes simply cannot access areas above a 20° gradient.

“It’s quite shocking when you look at distribution maps,” she says.

“Giraffes are tolerant animals and resilient to many things like food availability and human pressures, but this is a scenario where they simply may not be able to adapt due to physiological limits.”

Giraffes are found in 21 countries across Africa, but have been in decline due to habitat loss, poaching, and human-wildlife conflict. Despite conservation initiatives being critical to their survival, traditional habitat suitability models mainly focus on vegetation distribution, predation, and human disturbance – not topography.

Granweiler and collaborators used data from GPS collars fitted on 33 giraffes in South African reserves between 2011-2023. They combined this data with topographic maps to work out the gradients that giraffes could navigate.

“Steep and rugged environments are challenging for large-bodied animals, like giraffes,” says Susanne Shultz, also from the University of Manchester.

“Unfortunately, natural and protected areas are more likely to be placed in such places, which can lead to a mismatch between the landscapes animals ‘want’ to use and the landscapes that we have ‘left’ for them.

“Incorporating geography and physical limitations in habitat assessments can help avoid conserving animals in inappropriate places.”

After discovering the 20° threshold, the researchers calculated the proportion of inaccessible habitats in key African countries where giraffes are currently found.

“In Namibia and Tanzania, there is approximately 8,000km² that may be unusable to giraffes,” says Granweiler.

“In Kenya and South Africa, there’s approximately 4,000km² that may be unusable. What’s even more worrying is that of all the countries we mapped, 1 in 3 had more unusable areas in protected areas than outside of protected areas.”

This issue is exacerbated when reserves are fenced, like many in South Africa.

“If a reserve is 200 hectares but has a large mountain in the middle, from a giraffe’s perspective, this reserve is not 200 hectares anymore,” says Granweiler.

“We need to start including topography in giraffe conservation planning and habitat assessments, especially for small, fenced reserves.”