What is a consequence of the high specialization and endemism developed by Hawaiian *Hylaeus* species?
Their adaptation to very specific local conditions makes them extremely vulnerable to environmental shifts
The intense specialization that characterized the evolutionary success of the Yellow-faced Bees—particularly their endemism, meaning they are restricted to specific islands or host plants—is paradoxically the source of their current precarious status. When an organism's survival is tightly linked to a narrow set of local conditions, any significant negative change, such as habitat degradation or the introduction of non-native threats, can have catastrophic consequences because the species lacks the phenotypic plasticity or broad niche breadth to adapt quickly to new stressors. This vulnerability is starkly demonstrated by species like *Hylaeus finitimus*.
