The Northern Parula is a small and beautiful warbler that can be found high in the canopy of riparian forests, easily identified by its distinctive, buzzing song (sometimes compared to the sound made by running your nail along the teeth of a plastic comb). Northern Parulas are closely associated with epiphytes, flowering plants that grow on tree limbs often referred to as “air plants”. They forage in hanging moss for insects, and hollow out of clumps of the stuff to make their nests. This reliance on epiphytes makes the Northern Parula uniquely susceptible to air pollution: epiphytes, which absorb their nutrients from the air, can’t survive in areas with poor air quality, so Parulas, although not seriously harmed by air pollution, are robbed of homes by it. In central Texas, the northern Parula can be heard and seen throughout spring and summer in mature forests near water.