Caterpillars Count!

Arthropods are an important food source for birds and other wildlife. They also have economic and environmental impacts on our forests and crops. Caterpillars, a type of arthropod, are one of the most important sources of food for many migratory birds, and provide a tasty snack for growing nestlings.

Climate change is affecting the timing of spring leaf out, insect activity, and bird migration and breeding.

But are the plants, insects and birds all responding to the same degree?

If either insects or birds are not keeping up with phenological shifts of the other organisms that they depend on, then further climate change may have negative consequences for their populations.

The data you collect on the abundance and phenology of caterpillars and other insects during the growing season (spring and summer) is used by researchers to relate trends in arthropod populations to bird population trends in those same areas, and to better understand how changes in climate and land use impact the plants and animals around us.

Research questions your data help us answer include:

• Are caterpillars more abundant on certain tree species over others?
• Does the peak abundance of caterpillars vary from year to year, and has it been changing with climate?
• Does the peak abundance of caterpillars coincide with the time when birds are raising their young?