FIGURE 2.

Predicted interactive effects between rising temperatures and urbanisation in relation to the urban heat island (UHI) effect: Birds in urban areas might be genetically pre‐adapted to a warmer future through experiencing selective pressures of the UHI. The UHI might also result in accelerated temperature‐related changes to migration, phenology and pathogen assemblages, and an earlier onset of deleterious heat stress including heat‐related mortality. Cities in arid and semi‐arid regions show a modified UHI effect, often exhibiting lower temperatures than non‐urban areas during the day, buffering the above‐mentioned diurnal effects. The UHI under globally warming temperatures will likely continue to lead to relaxed thermoregulatory costs in temperate, continental and polar cities during winter, while exacerbating thermoregulatory costs in summer and in tropical cities compared with non‐urban environments.