Scientists uncover elephant’s extraordinary ability to plan journeys

By Stephen Beech

Elephants have an "extraordinary" ability to meet their colossal food needs as efficiently as possible, reveals new research.

Data from more than 150 African elephants shows that the iconic species plan their journeys based on energy costs and resource availability.

Conservationists say the findings, published in the Journal of Animal Ecology, could provide "crucial" information to help protect endangered elephants and their habitats.

As massive herbivores weighing several tons, the research team explained that elephants must consume "vast" amounts of low-calorie vegetation every day.

But their sheer bulk means that moving around to find food costs "significant" physical effort.

Every step matters in the vast, often harsh landscapes they traverse.

The research team said that understanding how elephants move through the landscape is essential for designing effective conservation plans, particularly as habitat fragmentation and human activities continue to threaten populations in Africa.

But, until now, key drivers behind elephant movements had been unclear.

The new study, led by researchers from the University of Oxford, the German Centre for Integrative Biodiversity Research (iDiv), and Friedrich-Schiller-University Jena, used GPS tracking data from 157 African elephants collected over 22 years from 1998 to 2020 in Northern Kenya.

Data was collected by Save the Elephants, a UK-registered, Kenya-based research and conservation charity.

The findings showed that elephants "strongly" prefer landscapes with lower movement costs, with 94% of the elephants studied avoiding steep slopes and rough terrain.

The researchers say that suggests they are aware of their surroundings and make cost-benefit decisions to choose the most energy-efficient paths.

The study also showed that elephants actively select areas with higher vegetation productivity, with 93% indicating a preference for resource-rich environments.

Water sources were also found to play a role in where elephants choose to go, but individual elephants can respond differently.

Some remain close to water sources, while others roam farther, showing that their movement choices are more complex than traveling to the nearest river or pond.

The research team also found that elephants moving at speed show an even stronger avoidance of difficult, more energetically costly terrain.

Three out of four elephants in the study (74%) avoided costly areas when moving slowly, which increased to 87% when moving at intermediate speeds and to 93% when moving fast.

The researchers say that suggests they carefully balance effort and energy efficiency, especially during long journeys.

The team believes the elephants’ behavior is comparable to birds appearing to deliberately use favorable thermal uplifts to reduce the energetic costs of flying.

The researchers used a modeling method called Enerscape, which estimates the energy costs of movement based on body mass and terrain slope.

Combining those estimates with satellite data on vegetation productivity and water availability, they built detailed energy landscapes that help explain elephants' movement decisions.

A statistical approach called step-selection functions was used to assess how elephants chose their paths.

The researchers say their findings could help guide the design of protected areas and migration corridors to reduce conflict with humans.

They believe the results could also help predict how elephant movements may respond to climate change, which affects both the energy costs of moving and the availability of food and water.

Study co-author Oxford University Professor Fritz Vollrath said: “While more detailed research is needed to fully understand how an elephant uses its habitat, this study identifies a central decision-making factor for travelling elephants: save energy whenever possible.”

Lead researcher Dr. Emilio Berti, of iDiv, added: “These new results have important implications for assessing and planning conservation and restoration measures, such as dispersal corridors, by explicitly accounting for the energy costs of moving.”

The researchers plan to refine energy landscape models by incorporating other factors including seasonal changes, human disturbances, and the impact of climate change on elephant movements.