The lone individual was caught and killed by people around 30 km from the border with Sudan, a paper in Mammalia reports.

"My first reaction was disbelief until I checked the photos and videos of the remains," said the study's lead author, Dr. Abdullah Nagy from Al-Azhar University, Egypt. "Seeing the evidence, I was completely taken aback. It was beyond anything we had expected to find in Egypt."

The sighting took place some 500 km north of the known range of spotted hyena in neighboring Sudan. The researchers theorized that a regional, decadal weather cycle, part of the Active Red Sea Trough phenomenon, could have resulted in increased rainfall and plant growth, opening up a migration corridor for the hyena where better grazing opportunities supported sufficient prey.

To test this idea, they used a normalized difference vegetation index (NDVI) as a measure of precipitation and corresponding pastoral grazing opportunity, with NDVI values obtained from Landsat 5 and 7 satellite images between 1984 and 2022.

Analysis revealed multi-year droughts with shorter relatively wet periods. The last five years had higher NDVI values than the previous two decades, suggesting increased plant growth could support prey for a curious spotted hyena on the move.

"The fact that the corridor area has become less environmentally harsh, offering easier passage along 'the highway,' may explain how the hyena reached this far north," says Nagy. "However, the motivation for its extensive journey into Egypt is still a mystery that demands further research."