Why does the Fennec Fox and the long-eared jerboa have such big ears?

The Fennec Fox and the long-eared jerboa have large ears primarily for thermoregulation and enhanced hearing. In their arid habitats, the large surface area of their ears helps dissipate heat, keeping them cool in hot environments. Additionally, their oversized ears enhance their ability to detect sounds, aiding in locating prey and avoiding predators. This adaptation is crucial for survival in their challenging ecosystems.