and air movement can affect where insects are active. If insects become easier to catch at lower altitudes, birds may follow them downward. Swallows, for example, are known for catching insects while flying, so their flight height can reflect where their prey is. The Royal Meteorological Society describes this as one reason swallows may fly lower when air pressure is low and rain is more likely: insects can be found closer to the ground.
That does not mean every bird is responding to the same conditions. Different species have different
