Abstract Previous work with the cryptic sister species pair of field crickets, Gryllus texensis Cade & Otte and Gryllus rubens Scudder, has implicated sexual selection in the speciation process. That study examined reproductive character displacement . . .

Abstract Most functional analyses of problem behavior include a common condition (play or noncontingent reinforcement) as a control for both positive and negative reinforcement. However, test?specific conditions that control for each potential source . . .