In today's lecture, we'll discuss the impact of urbanization on local ecosystems. One key point is that cities often create 'heat islands', where temperatures are significantly higher than surrounding rural areas due to concrete and asphalt absorbing heat. However, a lesser-known effect is on bird migration patterns. Many birds rely on natural landmarks for navigation, but tall buildings and artificial lights can confuse them, leading to collisions. Researchers in Chicago have found that turning off lights during peak migration seasons reduces bird deaths by up to 80%. This simple measure, known as 'Lights Out', is now adopted in over 30 cities worldwide.