When the artist Thomas Jackson began working on "Emergent Behavior," in 2011, he started with found objects. He collected fallen leaves in the Catskills and picked junk off the street in New York, then moved on to purchasing hundreds of cups and cheese balls, construction fences, glow necklaces, hula hoops, and balloons. He assembles these objects on outdoor frameworks, then photographs the installations. The resulting pictures show inanimate objects caught up in restless movement: some circle, some gather, some dip. In the color palette of a birthday party, Jackson's bits of plastic and rubber evoke schools of fish that move like ink in the water, or birds streaking the sky.