I am happy to report that Bear and Duke are now seeing eye to eye, as you can see from this picture. Once they had become acclimatized to each other, we let them loose together and studiously ignored both of them. I have to tell you though that the peripheral vision got a real workout while they were being "ignored"! Happily, they got along well. Bear is fascinated by Duke and his immense size - she runs as fast as she can trying to catch up with Duke and then when Duke turns around, she runs twice as fast the other way.
Once playtime is over, they flake out together like the best of friends!