Lions could prevent their prey from adapting to increasing heat, study says
Lions could limit their prey’s ability to adjust to warming temperatures, according to a new study making use of camera traps across southern Africa.
The research finds that prey species, such as gemsbok, zebra and waterbuck, switch to feeding at hotter times of the day when they are in the presence of lions. They do this because lions prefer to hunt in cooler times of the day.
The switch leaves these large herbivores more vulnerable to heat stress – and less able to adapt to rising temperatures, the lead author tells Carbon Brief.
Understanding how some animals could affect the adaptability of others “is an important step forward for projecting climate change risk to biodiversity”, another scientist tells Carbon Brief.
Balancing act
For mammals living in the African savannah, every day is a calculated balancing act between finding enough food and water and avoiding dangers, such as predators and heat stress.
Climate change could make this tightrope walk even narrower. Scientists expect that temperatures over the continent of Africa will rise at a faster rate than the global average.
To adapt to the increases in heat, many African mammals may need to try to change their behaviour or move into new areas. The new study, published in Nature Ecology and Evolution , explores why adapting to rising heat might not be straightforward for some species.
It finds that lions could limit the ability of their prey – medium-sized herbivores – to adapt to increasing heat, says study lead author Prof Michiel Veldhuis , an ecologist at Leiden University in the Netherlands. He tells Carbon Brief:
“Now the world is warming up, these herbivores face a tightening window and will probably, depending on their traits, respond in different ways.”
Caught on camera
For the research, the scientists used 32 camera traps spread across wildlife-protected areas in southern Africa, including South Africa and Eswatini. Veldhuis explains:
“Cameras take a picture when something moves in front of the camera and record the time. This makes it possible to investigate when animals are active and calculate overlap in activity between predators and prey.”
A camera trap image of a hippopotamus. Credit: Prof Joris Cromsigt
Lions had been hunted to extinction in all of the 32 sites around the 1950s. However, they were later reintroduced to around half of the sites. This provided the scientists with a “natural experiment” – allowing them to study how the presence or absence of lions could affect the activity of herbivores.
The researchers tracked the movements of 29 different herbivores in the African savannah, ranging in size from the “3kg scrub hare to the 4,000kg elephant”.
The map below shows the distribution of camera traps where lions were present (triangles) and (absent). The mean annual temperature is...
