African Elephants Have Sneaky Nighttime Feeds on Crops, but Avoid Raids During Full Moon Nights

New research from the UK's Anglia Ruskin University indicates that elephants track the lunar cycle and purposefully wait until nighttime to eat crops being grown by humans, often avoiding a "night raid" during a full moon when the night sky is illuminated.

The researchers studied troops elephants in Tanzania's Mikumi National Park in Tanzania, approximately 185 miles west of Dar es Salaam. The park has one of the largest wild elephant populations in Africa.

Five villages bordering the park were selected for the research; villagers and researchers took a record of instances when elephants raided crops being grown close to of within the villages.

Elephant "night raids" were found to vary in frequency throughout the lunar cycle, with significantly fewer raids during a full moon.

The extent of crop damage also fell considerably during the full moon phase.

"Our results support the belief that elephants alter their behavior to reduce the risks of encountering humans," said study author Rachel Grant, who lectures on Animal Behavior at Anglia Ruskin.

"Elephants are cathemeral, meaning they are active during day and night, but raid crops almost exclusively at night, suggesting they only venture close to villages when they believe they are harder to detect," Grant said.

"An elephant's awareness of the higher risk of being detected on moonlit nights, because of the visual advantage gained by humans, could account for the changes in their behavior during the lunar cycle and explain why elephants are less likely to venture close to villages during the full moon."

Grant said that some animals that vary their activity according to the lunar cycle have an internally arising biological rhythm, which could explains why the elephants prefer night raids. Alternatively the pachyderms may base their decision making on local conditions at the time, she said.

"Many animals alter their behavior according to varying light levels and the perceived risk of predation, and this is likely to be a partly evolved, partly learned response."

"This evidence of avoiding the full moon is likely to be a feature of elephant behavior in other populations outside of Tanzania and, importantly, could be used to provide information to help protect people's farms from the extensive damage these animals can cause."

Grant and her colleagues research is published in the African Journal of Ecology.