in short, yes. The migration of birds is heavely dependant on the environment they reside. Normally birds will migrate to warmer climates when there existing climate becomes cold. In England, we had a 2 week heat wave about 4 weeks ago. A week before that people were walking around with gloves and scarfs on. This heat wave had delayed some birds leaving. With sudden temperature changes birds will not be able to make an intelligent decision to leave or stay.