Tokyo Bay's night lights reveal hidden boundaries between species

A key characteristic of modern human society is rapid urbanization, a process that can reshape natural environments and disrupt the habitats of many organisms. One widespread byproduct of urbanization is artificial light at night (ALAN), which has become one of the most pervasive human-made environmental disturbances. ALAN can affect animals by changing their physiology, behavior, and geographic distribution. In particular, it disrupts natural day-night cycles, circadian rhythms, predator-prey interactions, and reproduction across a wide range of species.