These findings not only reshape our understanding of elephant intelligence and adaptability, but also provide important guidance for conservation strategies that must consider energy efficiency, individual behavior and a rapidly changing climate.
The life of an elephant is full of challenges. These giant herbivores, weighing several tons, need to eat large amounts of low-calorie plants every day. But their size also means that searching for food requires a lot of energy. In the vast and often harsh environment they inhabit, every step comes with a cost.
Understanding how elephants move across the landscape is critical to effective conservation, especially as habitat loss and human activities increasingly threaten their survival. Until recently, however, the main factors driving elephant movement patterns remained unclear.
Now, a new study led by researchers from the University of Oxford, the German Center for Integrated Biodiversity Research (iDiv) and Friedrich Schiller University Jena sheds light on the problem. The team used GPS tracking data from 157 African elephants collected in northern Kenya over a 22-year period (1998-2020) to analyze how elephants survive in their environment. The data was provided by Save the Elephants, a UK-based registered conservation organization based in Kenya.
Key findings:
Elephants are very fond of terrain with low travel costs, and 94% of elephants will avoid steep slopes and rugged terrain. This shows that they understand their surroundings and make cost-effective decisions, choosing the most energy-efficient path.
Elephants will actively choose areas with higher vegetation productivity, and 93% of elephants said they prefer resource-rich environments.
Water sources play an important role in elephant choice, but each elephant may respond differently. Some elephants stayed close to water sources, while others traveled further, suggesting their choices of movement were more complex than heading to the nearest river or pond.
Elephants moving at high speeds show stronger avoidance behavior on difficult, energy-intensive terrain. 74% of the elephants avoided areas that consumed more energy when moving at a slow speed, this proportion increased to 87% when moving at a medium speed, and to 93% when moving at a fast speed. This suggests that elephants find a balance between effort and energy efficiency, especially when traveling long distances.
According to the researchers, elephants behave similarly to birds and appear to intentionally take advantage of favorable thermal rise to reduce the energy expenditure of flight.
To analyze elephant tracking data, the research team used an innovative modeling method called ENERSCAPE, which estimates the energy expenditure of movement based on elephant weight and terrain slope. By combining these estimates with satellite data on vegetation productivity and water availability, they constructed a detailed energy landscape that helps explain the elephants' movement decisions.
The researchers used a statistical method called the step choice function to evaluate how elephants choose their paths. This technique compares the locations that elephants actually visit to other nearby areas that they could have chosen but didn't. By doing so, the researchers determined which environmental factors play a role in elephants' movement decisions and habitat selection.
The findings have direct applications to wildlife conservation and could help guide the design of protected areas and migration corridors to reduce conflicts with humans. The study also suggests that conservation strategies should take into account individual differences in habitat preferences, particularly in water access.
The findings could also help predict how elephant migrations will respond to climate change, which affects both the energy costs of migration and the availability of food and water.
In the future, the researchers aim to refine the energy landscape model by incorporating other factors such as seasonal changes, human disturbance and the impact of climate change on elephant activity.
Co-author Professor Fritz Vollrath (University of Oxford) said: "While more detailed research is needed to fully understand how elephants use their habitat, this study identifies a core decision-making factor for elephants traveling: saving as much energy as possible."
Lead researcher Dr. Emilio Berti (German Center for Integrated Biodiversity Research and Friedrich Schiller University Jena) adds: "These new results have important implications for the evaluation and planning of conservation and restoration measures, such as evacuation corridors, since these measures explicitly take into account the energetic costs of movement."
Compiled from /ScitechDaily