In a large bowl toss together black beans, corn, chicken, cilantro, and red pepper. Set aside. In a small bowl stir together yogurt and chipotle mayonnaise and stir sauce into chicken mixture until well combined. Chill, covered, 1 hour for flavors to develop. Serve in avocado halves.
Mince chipotle chile to a paste with 1/2 teaspoon of adobo sauce. In a bowl stir all ingredients together until combined well. Sauce may be made 1 week ahead and chilled, covered.
*available in specialty shops and mail order from Mo Hotto-Mo Betta (800) 462-3220.