Answer:
The black and yellow bird population would begin to starve and would be forced to find alternative food, or die off. This would then send ripples through the food web, causing almost every species to be effected by the grasshoppers being gone.
"Crepuscular" means active at dawn and dusk, so if you wanted to avoid coming across the Gila monster when hiking in Arizona you would want to avoid dawn and dusk.
