Which mountain cliffs do Apis laboriosa honey bees select as nesting sites and why?
Jerzy Woyke, Jerzy Wilde and Maria Wilde
Apis laboriosa and Apis dorsata are closely related migratory open-air nesting bees which nest at mountain cliffs. It is not known why they select certain cliffs over others. We examined 16 nesting cliffs, at which 258 A. laboriosa colonies nested. The studies were conducted in Nepal in 1998 and 1999 and in Bhutan in 2008. Most cliffs are of a grey to black colour, but all A. laboriosa bees selected as nesting sites light -coloured unweathered cliffs. The light cliffs appear as a result of water erosion, and the unweathered cleared surface assures strong fixation of the combs to the rock. This way the nest will not tear away from the cliff overhangs. Near some nests, a white area is present on the vertical wall of the cliff. This is the surface cleared by bees, which previously nested here. It is possible to spot actual or potential nesting cliffs of these bees from far away.