Fig. 1. The proportion of species declining in each jurisdiction (states and provinces), and locally weighted regression lines for aerial insectivorous passerines (circles and solid lines) and for all other passerines (squares and stippled lines) in the lower 48 United States and in southern Canada. Aerial insectivores in the east and north of North America are disporpotionately more likely to be declining than other passerine species in these areas.