Arecycling station accidentally mixed together hundreds of glass jars with steel cans. what is the easiest way way to separate the cans from the jars

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food