Urban heat islands, created by impervious surfaces and waste heat from buildings and vehicles, are creating thermal stress in urban wildlife and altering the phenology and distribution of species adapted to cooler conditions.
Urban wildlife faces increasing thermal stress as heat islands intensify with climate change. Animals with limited thermoregulatory capacity, including hedgehogs, urban foxes, and many invertebrates, experience physiological distress during heatwaves. Heat stress suppresses immune function, reduces foraging efficiency, and can cause direct mortality in vulnerable individuals. Phenological mismatches driven by urban heat alter the availability of food sources and can lead to nutritional deficits for species that cannot adapt rapidly.